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Systematic Review

The Global Prevalence of Bacillus spp. in Milk and Dairy Products: A Systematic Review and Meta-Analysis

by
Tianmei Sun
1,
Ran Wang
1,
Yanan Sun
1,
Xiaoxu Zhang
1,
Chongtao Ge
2,* and
Yixuan Li
1,*
1
Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China
2
Aseptic Science and Technology, R&D AP, SIG Combibloc (Suzhou) Co., Ltd., Suzhou 215028, China
*
Authors to whom correspondence should be addressed.
Foods 2025, 14(15), 2599; https://doi.org/10.3390/foods14152599
Submission received: 25 June 2025 / Revised: 17 July 2025 / Accepted: 23 July 2025 / Published: 24 July 2025
(This article belongs to the Special Issue Predictive Modelling in Food: Food Safety Validation and Risk Assessment)
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Abstract

The spoilage of dairy products and foodborne diseases caused by Bacillus spp. are important public concerns. The objective of this study was to estimate the global prevalence of Bacillus spp. in a range of milk and dairy products by using a meta-analysis of literature data published between 2001 and 2023. A total of 3624 publications were collected from Web of Science and PubMed databases. Following the principles of systematic review, 417 sets of prevalence data were extracted from 142 eligible publications. Estimated by the random-effects model, the overall prevalence of Bacillus spp. in milk and dairy products was 11.8% (95% CI: 10.1–13.7%), with highly severe heterogeneity (94.8%). Subgroup analyses revealed substantial heterogeneity in Bacillus spp. prevalence according to geographical continents, sources of sampling, types of dairy products, microbial species, and detection methods. The prevalence of Bacillus spp. was highest in Asia (15.4%, 95% CI: 12.3–19.1%), lowest in Oceania (3.5%, 95% CI: 3.3–3.7%) and generally higher in developing versus developed countries. The prevalence of Bacillus spp. isolated from retail markets (16.1%, 95% CI: 13.0–19.7%) was higher than from farms (10.3%, 95% CI: 6.9–15.0%) or dairy plants (9.2%, 95% CI: 7.1–12.0%). This finding is likely attributable to its inherent characteristic of the resistant endospores and ubiquitous presence in the environment—Bacillus spp. can potentially cyclically contaminate farms, dairy products and human markets. Regarding the species distribution, Bacillus cereus presented a cosmopolitan distribution across all continents. The epidemic patterns of different Bacillus species vary depending on the sample sources. In addition, the detection method utilized also affected the reported prevalence of Bacillus spp. It is recommended to use molecular-based rapid detection methods to obtain a more accurate prevalence of Bacillus contamination. Therefore, a better understanding of variations in Bacillus spp. prevalence across different factors will enable competent authorities, industries, and other relevant stakeholders to tailor their interventions for effectively controlling Bacillus spp. in milk and dairy products.

1. Introduction

For centuries, dairy products such as milk, cheese, and yogurt have been recognized as essential components of the human diet, owing to their high nutrient content and moisture, and are consumed by people across all age groups worldwide [1,2]. Meanwhile, dairy products are also highly susceptible to microbial spoilage due to their favorable conditions for microbial growth, including the presence of nutritious proteins and fats [3]. The spoilage of dairy products caused by microbial contamination may result in substantial financial losses and damage to reputation [4]. In the dairy sector, spoilage causes losses of billions of dollars every year; in Europe, it accounts for 20% of the annual total production losses [5]. Furthermore, dairy products are a major source of bacteria-associated foodborne diseases, responsible for 4% of the global foodborne disease burden. This causes an annual economic burden of at least $4 billion in low- and middle-income countries [6,7]. Therefore, the need to increase knowledge on microbial contamination is fundamental to improving the quality of dairy products.
The contamination of milk and dairy products with endospore-forming bacteria is a daily challenge for the dairy industry. Members of the Bacillus genus with general characteristics of gram-positive, rod-shaped, aerobic and endospore-forming are among the most common bacteria encountered in the dairy environments [8,9]. Due to the abundant presence of these bacteria in the natural environment and their ability to form endospores, they can survive in various stress conditions, thereby maintaining endurance over a wide range of temperatures and pH values [10,11]. Moreover, highly resistant endospores of Bacillus species can protect them from food processing such as drying, pasteurization, etc. [12,13]. Germination and outgrowth of endospores of Bacillus species are not only associated with spoilage of milk but also responsible for foodborne diseases [14]. Among the endospore-forming Bacillus species, Bacillus cereus group is well known for its potential to cause two forms of food poisoning, namely the emetic and diarrheal syndromes [15]. Also, other Bacillus species, including Bacillus licheniformis, Bacillus amyloliquefaciens, and Bacillus pumilus, can produce toxic components such as surfactin, amylosin, and pumilacidin, contributing to food safety concerns [4,16,17]. Due to the potential hazard posed by Bacillus species in dairy products, there has been a substantial increase in related scientific publications. However, due to differences in regions, sampling plans, and detection methods, there is significant heterogeneity in the prevalence data [18]. It is thus critical to regularly review the published literature and obtain up-to-date insights to gain a comprehensive and systematic understanding of the prevalence of Bacillus spp. in milk and milk products worldwide.
Meta-analysis can use statistical approaches to combine the results from multiple individual studies on a specific research question. Additionally, meta-analysis can be used to identify the sources of heterogeneity or differences among findings of the primary studies [19]. In the past few years, meta-analysis has been increasingly applied to address a broad range of food safety issues such as disease incidence, prevalence and concentrations of microorganisms, effects of interventions, consumer practices, etc. [20,21,22,23,24]. The results from such independent meta-analyses can further provide valuable quantified estimates as input into microbial risk assessment models.
The present study was designed to use the meta-analysis tool to obtain an overview of the prevalence of Bacillus spp. in different types of milk and dairy products worldwide. It also aimed to delineate the distribution of Bacillus species, evaluate the variations in the prevalence of Bacillus in different geographical regions and determine the effect of microbial detection methods on the prevalence.

2. Materials and Methods

2.1. Search Strategy

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used to perform this systematic review [25]. The research question guiding the data search was “estimate the prevalence of Bacillus spp. in milk and dairy products worldwide and evaluate the effects of different sampling factors on Bacillus spp. prevalence level”. A comprehensive search was performed for the prevalence of Bacillus spp. in two databases, i.e., Web of Science (WoS) and PubMed, using the same keywords. The following keywords were used as search queries in each database: “Bacillus” AND (“dairy products” OR “dairy” OR “milk products” OR “milk” OR “cream” OR “ice cream” OR “cheese*” OR “butter” OR “yogurt”) AND (“incidence” OR “prevalence” OR “prevalence rate*” OR “occurrence” OR “concentration” OR “contamination” OR “count” OR “survey” OR “sampling”). The search was limited to publication dates from 1 January 2000 to 31 December 2023. Publications with any of the selected keywords in the abstract, title, or main text were included.

2.2. Selection Criteria

During the screening stage of publications, in accordance with PRISMA guidelines, possible and suitable criteria regarding the objectives of the present study were considered in the screening and selection of obtained data [26]. After removing duplicate records, all the articles were checked according to a set of exclusion criteria. A study was excluded if (1) it was published as a conference abstract or was not a research paper (review); (2) it was not relevant, such as studies focusing on the detection method, predictive modeling, or hurdle technology; (3) it had overlapping information; (4) incomplete data on the prevalence and concentration of Bacillus spp. in dairy products were reported; (5) the sample size was lower than 20; (6) full text was not found. To minimize possible error, two researchers reviewed the publications separately.

2.3. Data Extraction

Data for Bacillus spp. prevalence on milk and dairy products were extracted from the studies identified through the systematic review of the literature independently by a single reviewer and validated by a second reviewer. The following data were extracted from each eligible study of records: author, publication year, survey year, dairy product category, sampling location (i.e., continent and country), source of sampling (i.e., farm, dairy plant, or retail market), detection method, sample size, number of positive samples, and identified Bacillus species. Subgroup analysis was conducted using the following potential moderator variables: types of milk and dairy products, geographic regions, sources of sampling, Bacillus species, and detection methods.

2.4. Meta-Analysis and Statistical Analyses

In this meta-analysis, the positive samples ( p i ) divided by the total sample size ( n i ) indicates the prevalence of Bacillus spp. in milk and dairy products ( I = p i n i ). The pooled prevalence was calculated using random-effects models [with 95% confidence intervals (95% CI)]. Cochran’s Q test and the I-square index ( I 2 ) were used to detect heterogeneity between studies. The statistical significance for heterogeneity using Cochran’s Q test was defined as p < 0.05 , and the degree of heterogeneity using I 2 was defined as low, moderate, and high when I 2 values (as percentages) were around 25%, 50%, and 75% [27]. No publication bias is considered when the prevalence rate is obtained based on the ratio of positive sample size to total sample size [28,29]. Meta-analysis and forest plot generation in this study were conducted using R (version 4.4.3, http://www.R-project.org/ accessed on 1 January 2025), specifically the ‘meta’ package.

3. Results and Discussion

3.1. Systematic Review Process

Figure 1 summarizes the systematic review process conducted for this study. A total of 3624 publications were initially extracted from two selected databases. After deduplication, 2913 unique studies remained for relevance screening. Of the 2913 studies, 2125 were excluded during the title and abstract screening due to the lack of the mentioned inclusion criteria. A total of 788 studies were entered into the selection phase to be evaluated based on full text eligibility (inclusion and exclusion) criteria. Finally, 142 articles were deemed relevant with data successfully extracted. The included studies described Bacillus spp. prevalence in milk and dairy products in various countries all over the world.

3.2. Overall Prevalence of Bacillus spp.

Given the large number of included studies (142) and the wide range of dairy product type, Table 1 provides a summary of the meta-analysis. In this meta-analysis, a total of 54,772 samples were tested, including liquid milk, cheese, milk powder, ice cream, concentrated milk, other dairy products, and environmental samples. The overall pooled prevalence of Bacillus spp. in milk and dairy products was 11.8% (95% CI: 10.1–13.7%) based on all studies included in this global meta-analysis, with heterogeneity (as indicated by the inverse variance index) as high as 94.8%. Subsequently, subgroup analysis was conducted to identify the causes of heterogeneity.

3.3. Prevalence of Bacillus spp. Considering Geographic Regions

For the geographic region subgroup, the results showed that the rank order of pooled prevalence of Bacillus spp. in milk and dairy products was Asia > Africa > Europe > America > Oceania. The highest prevalence of Bacillus spp. was in Asia at 15.4% (95% CI: 12.3–19.1%) and the lowest prevalence was observed in Oceania at 3.5% (95% CI: 3.3–3.7%) (Table 2). The largest sample size was reported in studies across America. Conversely, Africa had the lowest number of included studies as well as the smallest sample size.
The prevalence of Bacillus spp. in milk and dairy products investigated in different countries varies substantially. A total of 42 countries from five continents were included in this study (see Supplementary Material Table S1). In Asia, Bangladesh showed the highest prevalence of Bacillus spp. in milk and dairy products (29.2%) and Korea showed the lowest (4.7%). In Africa, the prevalence of Bacillus spp. in dairy products was 13.9% (95% CI: 9.3–20.3%) which was the second-highest prevalence after Asia, although Africa had the fewest samples in this subgroup analysis. In Africa, the highest prevalence reported was in Ghana (39.1%), and the lowest was in Algeria (3.6%). In Europe, the pooled prevalence of Bacillus spp. was 11.4% (95% CI: 8.2–15.6%) which was the lowest after Africa. Among European countries, the highest prevalence of Bacillus spp. was reported in Germany and the lowest was in Britain. These study results, consistent with previous studies [11], show a higher prevalence of Bacillus spp. in food in developing countries (e.g., Ghana, Bangladesh, and Pakistan) compared to developed countries. Notably, exceptions were observed; Germany, despite being a developed country, reported a very high prevalence of Bacillus spp. contamination. Therefore, Bacillus spp. contamination also warrants attention in developed countries. The observed difference may be caused by variations in sample size, sampling method, environmental conditions, etc. [30]. In terms of environmental conditions, hygiene practices and climates (e.g., temperature, humidity) are the key factors influencing the prevalence of Bacillus spp. in both developing and developed countries. Poor hygienic conditions during milking, processing, and storage may significantly accelerate cross-contamination risks, thereby increasing the prevalence of Bacillus spp. [31]. Furthermore, warmer climates characteristic of tropical regions create favorable conditions for the growth and multiplication of microorganisms, potentially explaining the increased prevalence of Bacillus spp. observed in these geographical areas in this study [32,33,34]. Therefore, it is logical that the Bacillus prevalence in milk and dairy products varies between different geographical regions.

3.4. Prevalence of Bacillus spp. Considering the Source of Sampling and Type of Samples

In terms of sample sources, the prevalence of Bacillus spp. varied among samples from different sources. In this study, 92.64% (50,741 out of 54,772) of the total samples had definitive source information, among which 10,764 samples were isolated from farms, 24,581 samples were from dairy plants and 15,216 samples were from retail markets. As shown in Table 3, the pooled prevalence of Bacillus spp. isolated from retail markets (16.1%, 95% CI: 13.0–19.7%) was significantly higher than that from farms (10.3%, 95% CI: 6.9–15.0%) and dairy plants (9.2%, 95% CI: 7.1–12.0%). Due to their abundant presence in the natural environment, Bacillus spp. and their endospores have a high chance of circularly contaminating farms, dairy products, and human markets [35].
In the present study, we divided the types of included samples into seven categories: liquid milk, cheese, milk powder, ice cream, concentrated milk, other dairy products and environmental samples. The proportion of liquid milk samples was the largest (45.0%, 24,662/54,772), accounting for nearly half of the total included samples, followed by milk powder samples and cheese samples. Among the isolated samples from farms, the pooled prevalence of Bacillus spp. was relatively high in milk powder samples and environmental samples, which were 73.3% and 45.5% respectively. Though milk powder samples from farms showed the highest pooled prevalence result, it may need more investigations as only one study was included in this subgroup, which is insufficient in terms of representativeness [36]. The lack or the scarcity of representative research may generate a misconception about the real prevalence result [29]. By contrast, the significantly higher prevalence of Bacillus spp. in farm environmental samples is more conclusive. Its high prevalence may be due to the abundant presence of Bacillus endospores in the soil and consequent contamination of grass, feed, bedding material, air and cows [37]. This result is in accordance with findings of previous studies, which show that vegetables and cereals usually have a high prevalence of Bacillus species, indicating the impact from natural environmental factors such as soil contamination in agricultural products [11,38,39]. Thus, the environmental conditions of farms are one of the main sources of Bacillus spp. in dairy products. Strict farm management is necessary to decrease the contamination of Bacillus spp. at the farm level.
Among the isolated samples from dairy plants, the highest pooled prevalence of Bacillus spp. was found in cheese samples, at 24.2%. Likewise, Bacillus is also a major contaminant in retail ice cream and cheese samples. The pooled prevalence of Bacillus spp. contamination in retail ice cream and cheese samples was 44.2% and 17.6%, respectively. These findings further confirm that Bacillus species can grow and/or survive in foods with lower pH and at freezing temperatures. Cheese samples are a group of fermented milk-based food products that are produced in various flavors and forms around the world [40]. During the cheesemaking stage, the use of raw milk and the manufacturing process are the primary sources of microbial contamination [41,42]. A compilation of studies from 1973 to 2006, conducted in Switzerland, the United States, Sweden, Canada, France, Brazil, the United Kingdom, Spain, Malta, Scotland, England, and Finland, analyzed 84 cheese-associated outbreaks. The results showed that 69.0% of the outbreaks were linked to cheeses made from raw milk, while 7.2% involved cheeses without heat treatment [43]. In Brazil, 8% of the reported foodborne outbreaks related to artisanal cheeses made with raw milk were caused by Bacillus cereus contamination [44]. Furthermore, it is worth noting that the liquid milk samples from retail markets had a significantly higher prevalence of contamination than those sourced directly from farms or dairy plants. This elevated prevalence may also be related to the consumption of raw milk. Previous studies on milk consumption practices revealed that some people refrain from heating milk before consumption because they believe that heat treatment is detrimental to nutritional quality [45,46]. In several European countries, like France, Germany, and parts of the UK, raw milk may be available through numerous distribution channels, including direct sale to consumers at farms, sale through approved retailers, vending machines and the internet [47]. A study performed by Peng et al. indicated that raw milk posed higher contamination risks of aerobic Bacillus, with a prevalence of 54.02%, compared to pasteurized milk (14.41%) and sterilized milk (1.30%) [48]. Additionally, liquid milk samples in the retail markets often undergo temperature fluctuations during cold chain transportation and subsequent shelf-life storage, which may pose a risk for Bacillus spp. multiplication and recontamination [49]. Therefore, enhancing raw milk quality, ensuring adequate heat treatment, and maintaining cold chain transportation and storage are of great importance for achieving the quality and safety of dairy products.
Another reason for the high prevalence of Bacillus spp. in retail samples may be that dairy products are often sold in bulk or without aseptic packaging in some small-scale stores. Aseptic packaging, which involves sterilizing dairy products and sealing them in sterilized packages, has been growing in popularity due to its ability to enhance dairy safety and sustainability [50]. When at retail, unpackaged dairy products may be at a higher risk of exposure to microbial contamination during the handling process. Taken together, subgrouping based on the types of samples in addition to the source of samples can affect the pooled key measure levels.

3.5. Distribution of Bacillus Species

In this survey, a total of 35 species of the Bacillus genus were reported. The pooled prevalence calculation results for each Bacillus species in milk and dairy products are given in Table 4. Of these, Bacillus sporothermodurans (36.5%, 95% CI: 21.8–54.3%), followed by Bacillus licheniformis (26.3%, 95% CI: 16.0–40.1%) and Bacillus cereus (19.8%, 95% CI: 16.6–23.3%), are the most prevalent species contaminating milk and dairy products. Meanwhile, in terms of the number of studies and samples analyzed, B. licheniformis and B. cereus received considerable attention from researchers.
Figure 2 displays a worldwide distribution of Bacillus species by continents. B. cereus, B. pumilus and B. subtilis presented a ubiquitous profile, having been detected in milk and dairy products across all continents. Among these three species, the overall prevalence of B. cereus was the highest. This finding is supported by the fact that this species is commonly known for food pathogenicity within the Bacillus genus and has been reported in foodborne outbreaks worldwide. In the United States, B. cereus was linked to 1.74% of reported foodborne outbreaks from 1998 to 2008 [51]. In China, it accounted for 11.2% of outbreaks caused by pathogenic microorganisms between 2011 and 2016 [52]. In 2015, the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC) reported that B. cereus ranked as the fourth most common cause of foodborne outbreaks in the European Union [53]. Food poisoning caused by B. cereus accounted for 17.8% of the total bacterial outbreaks in Finland, 11.5% in The Netherlands, 2.2% in Canada, 0.8% in Scotland, 0.7% in England and Wales, and 0.7% in Japan [54]. In addition, B. subtilis and B. pumilus have also been reported in connection with food poisoning due to their ability to produce toxic substances in food [55,56]. Nowadays, given the significant impact on public health of pathogenic Bacillus species in milk and dairy products, an increasing number of studies have been conducted to investigate their prevalence.
Figure 3 illustrates the distribution of Bacillus species in different types of dairy products from different sampling sources. Variations existed in the prevalence patterns of different Bacillus species depending on the sample sources. Overall, B. cereus and B. licheniformis were commonly detected in different types of samples across various sampling sources. In contrast, B. sporothermodurans was predominantly detected only in dairy plants and retail markets. According to the prevalence results, this study identified high-risk associations between Bacillus species and dairy products, including B. cereus in farm-sourced environments, B. licheniformis in farm-sourced cheese, B. sporothermodurans in dairy plant-sourced liquid milk products, B. licheniformis in dairy plant-sourced cheese, B. cereus in retail-sourced ice cream, and B. licheniformis in retail-sourced milk powder. On the other hand, these variations in this subgroup analysis may be related to the inherent characteristics of Bacillus endospores. Endospore-forming bacteria, especially B. sporothermodurans and B. licheniformis, can produce high thermoresistant endospores that can survive at an ultra-high temperature (UHT) [57]. The D140 °C-values of B. sporothermodurans endospores from UHT milk isolates vary between 3.4 and 7.9 s [58,59]. Furthermore, B. cereus, B. sporothermodurans and B. licheniformis also have been reported to have a strong ability to adhere to the surfaces of industrial equipment and form biofilms. The above characteristics help them survive and persist at all stages of farms, dairy plants and retailers, thus becoming frequently prevalent among different dairy products.

3.6. Prevalence of Bacillus spp. by Detection Methods

The detection methods of Bacillus spp. in the included studies were divided into three groups: culture–biochemical, culture–molecular, and culture–biochemical–molecular (see Table 5). The pooled prevalence of Bacillus spp. was calculated for each method. The results showed that the pooled prevalence of Bacillus spp. in milk and dairy products based on the detection method was 9.2% (95% CI: 7.4–11.3%) for the culture–biochemical method, 16.6% (95% CI: 13.1–20.8%) for the culture–molecular method, and 10.8% (95% CI: 6.6–17.0%) for the culture–biochemical–molecular method. This subgroup analysis based on detection methods indicated that this variable had a considerable effect on Bacillus prevalence in milk and dairy products.
As shown in Table 5, among the included studies, the culture-biochemical method was the most widely applied approach, having been used in the largest number of samples tested for Bacillus spp. This traditional biochemical method is known as the “gold standard” due to its sensitivity, low cost, and operational simplicity. However, this approach is also regarded as time-consuming and labor-intensive [60]. In addition, there is a probability that false negative results may occur due to viable but nonculturable cells (VBNC) [61]. Therefore, alternative molecular detection methods like polymerase chain reaction (PCR) methods are required to detect microorganisms more easily, quickly, and with high accuracy, reliability and sensitivity. The molecular methods are based on the amplification of specific DNA sequences and enable the detection of microorganisms even at low microbial concentrations [62]. Hence, the results of this subgroup analysis showed that the pooled prevalence of Bacillus spp. in milk and dairy products detected by molecular and biochemical-molecular methods was higher than that detected by the biochemical method alone. The use of molecular-based rapid detection methods for bacterial identification can provide more robust results.

4. Conclusions

In recent years, there has been a considerable rise in the demand for milk and dairy products. Compared with other foods, milk and dairy products are particularly susceptible to microbial contamination throughout the farm-to-table chain and are subject to rapid spoilage and foodborne diseases. In the present systematic review, the global prevalence of Bacillus spp. in milk and dairy products based on defined subgroups was meta-analyzed. The results revealed that the prevalence of Bacillus spp. in developing countries is higher than that in most developed countries. The prevalence and species distribution of Bacillus spp. also varied among different types of milk and dairy products from different sources. Notably, B. cereus, as a pathogenic species within the Bacillus genus, was found to be widespread across all continents and in diverse dairy products globally, posing a greater potential risk to consumers. These findings underscore the imperative of implementing stringent, enforceable, and monitorable hygiene standards (covering facilities, equipment, processes, personnel, and the environment) to prevent the spread of contamination by Bacillus spp. and their endospores. However, due to the lack of detailed sampling information (e.g., the time when dairy products leave the processing plant, transport time, storage time in retail, etc.) limiting this study, it is impossible to further predict dynamic contamination patterns of Bacillus species. Implementing rigorous microbial sampling and monitoring frameworks coupled with more accurate detection methods, such as PCR and other molecular techniques, can yield more precise prevalence data. In the future, the integration of such data can better assess the ultimate exposure and risk of Bacillus species in dairy products and assist government authorities, industry, and other relevant stakeholders in enhancing food safety and preventing new outbreaks.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/foods14152599/s1, Table S1: Prevalence and sample size of Bacillus spp. based on countries.

Author Contributions

Conceptualization, T.S., C.G., and Y.L.; methodology, T.S.; software, T.S.; validation, T.S., C.G., and R.W.; formal analysis, T.S.; investigation, T.S., Y.S., and X.Z.; resources, C.G.; data curation, T.S. and C.G.; writing—original draft preparation, T.S.; writing—review and editing, C.G., R.W., and Y.L.; visualization, T.S.; supervision, C.G.; project administration, Y.L.; funding acquisition, Y.L. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the 111 Project of the Education Ministry of China (No. B18053).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

No new data were created or analyzed in this study. Data sharing is not applicable to this article.

Acknowledgments

We thank SIG Combibloc (Suzhou) Co., Ltd. for funding this project and providing technical guidance.

Conflicts of Interest

Author Chongtao Ge was employed by SIG Combibloc (Suzhou) Co., Ltd. This author declares that this study received funding and technical guidance from Aseptic Science and Technology, R&D AP, SIG Combibloc (Suzhou) Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

  1. Górska-Warsewicz, H.; Rejman, K.; Laskowski, W.; Czeczotko, M. Milk and Dairy Products and Their Nutritional Contribution to the Average Polish Diet. Nutrients 2019, 11, 1771. [Google Scholar] [CrossRef] [PubMed]
  2. Yang, S.; Bhargava, N.; O’Connor, A.; Gibney, E.R.; Feeney, E.L. Dairy Consumption in Adults in China: A Systematic Review. BMC Nutr. 2023, 9, 116. [Google Scholar] [CrossRef] [PubMed]
  3. Das, S.; Saha, A.; Aggarwal, K. Natural Biopreservatives for Dairy Products: Microbial and Plant-Derived Solutions and Recent Advancements. Int. Dairy J. 2025, 166, 106256. [Google Scholar] [CrossRef]
  4. Pereira, A.P.M.; Sant’Ana, A.S. Diversity and Fate of Spore Forming Bacteria in Cocoa Powder, Milk Powder, Starch and Sugar during Processing: A Review. Trends Food Sci. Technol. 2018, 76, 101–118. [Google Scholar] [CrossRef]
  5. Quintieri, L.; Caputo, L.; Brasca, M.; Fanelli, F. Recent Advances in the Mechanisms and Regulation of QS in Dairy Spoilage by Pseudomonas spp. Foods 2021, 10, 3088. [Google Scholar] [CrossRef] [PubMed]
  6. Pires, S.M.; Vieira, A.R.; Perez, E.; Wong, D.L.F.; Hald, T. Attributing Human Foodborne Illness to Food Sources and Water in Latin America and the Caribbean Using Data from Outbreak Investigations. Int. J. Food Microbiol. 2012, 152, 129–138. [Google Scholar] [CrossRef] [PubMed]
  7. Grace, D.; Wu, F.; Havelaar, A.H. MILK Symposium Review: Foodborne Diseases from Milk and Milk Products in Developing Countries—Review of Causes and Health and Economic Implications. J. Dairy Sci. 2020, 103, 9715–9729. [Google Scholar] [CrossRef] [PubMed]
  8. Sharma, M.; Anand, S.K. Characterization of Constitutive Microflora of Biofilms in Dairy Processing Lines. Food Microbiol. 2002, 19, 627–636. [Google Scholar] [CrossRef]
  9. Ostrov, I.; Sela, N.; Belausov, E.; Steinberg, D.; Shemesh, M. Adaptation of Bacillus Species to Dairy Associated Environment Facilitates Their Biofilm Forming Ability. Food Microbiol. 2019, 82, 316–324. [Google Scholar] [CrossRef] [PubMed]
  10. Cempírková, R. Psychrotrophic vs. Total Bacterial Counts in Bulk Milk Samples. Vet. Med. 2002, 47, 227–233. [Google Scholar] [CrossRef]
  11. Flint, S.; Gonzaga, Z.J.; Good, J.; Palmer, J. Bacillus Thermoamylovorans—A New Threat to the Dairy Industry—A Review. Int. Dairy J. 2017, 65, 38–43. [Google Scholar] [CrossRef]
  12. Chemat, F.; Rombaut, N.; Meullemiestre, A.; Turk, M.; Perino, S.; Fabiano-Tixier, A.-S.; Abert-Vian, M. Review of Green Food Processing Techniques. Preservation, Transformation, and Extraction. Innov. Food Sci. Emerg. Technol. 2017, 41, 357–377. [Google Scholar] [CrossRef]
  13. Rahnama, H.; Azari, R.; Yousefi, M.H.; Berizi, E.; Mazloomi, S.M.; Hosseinzadeh, S.; Derakhshan, Z.; Ferrante, M.; Conti, G.O. A Systematic Review and Meta-Analysis of the Prevalence of Bacillus Cereus in Foods. Food Control 2023, 143, 109250. [Google Scholar] [CrossRef]
  14. Faille, C.; Bénézech, T.; Midelet-Bourdin, G.; Lequette, Y.; Clarisse, M.; Ronse, G.; Ronse, A.; Slomianny, C. Sporulation of Bacillus spp. within Biofilms: A Potential Source of Contamination in Food Processing Environments. Food Microbiol. 2014, 40, 64–74. [Google Scholar] [CrossRef] [PubMed]
  15. Fogele, B.; Granta, R.; Valciņa, O.; Bērziņš, A. Occurrence and Diversity of Bacillus Cereus and Moulds in Spices and Herbs. Food Control 2018, 83, 69–74. [Google Scholar] [CrossRef]
  16. Lücking, G.; Stoeckel, M.; Atamer, Z.; Hinrichs, J.; Ehling-Schulz, M. Characterization of Aerobic Spore-Forming Bacteria Associated with Industrial Dairy Processing Environments and Product Spoilage. Int. J. Food Microbiol. 2013, 166, 270–279. [Google Scholar] [CrossRef] [PubMed]
  17. Logan, N. Bacillus and relatives in foodborne illness. J. Appl. Microbiol. 2012, 112, 417–429. [Google Scholar] [CrossRef] [PubMed]
  18. Ortuzar, J.; Martinez, B.; Bianchini, A.; Stratton, J.; Rupnow, J.; Wang, B. Quantifying Changes in Spore-Forming Bacteria Contamination along the Milk Production Chain from Farm to Packaged Pasteurized Milk Using Systematic Review and Meta-Analysis. Food Control 2018, 86, 319–331. [Google Scholar] [CrossRef]
  19. Gonzales-Barron, U.; Butler, F. The Use of Meta-Analytical Tools in Risk Assessment for Food Safety. Food Microbiol. 2011, 28, 823–827. [Google Scholar] [CrossRef] [PubMed]
  20. den Besten, H.M.W.; Zwietering, M.H. Meta-Analysis for Quantitative Microbiological Risk Assessments and Benchmarking Data. Trends Food Sci. Technol. 2012, 25, 34–39. [Google Scholar] [CrossRef]
  21. Gonzales-Barron, U.; Cadavez, V.; Sheridan, J.J.; Butler, F. Modelling the Effect of Chilling on the Occurrence of Salmonella on Pig Carcasses at Study, Abattoir and Batch Levels by Meta-Analysis. Int. J. Food Microbiol. 2013, 163, 101–113. [Google Scholar] [CrossRef] [PubMed]
  22. Gonzales-Barron, U.; Gonçalves-Tenório, A.; Rodrigues, V.; Cadavez, V. Foodborne Pathogens in Raw Milk and Cheese of Sheep and Goat Origin: A Meta-Analysis Approach. Curr. Opin. Food Sci. 2017, 18, 7–13. [Google Scholar] [CrossRef]
  23. Liu, Y.; Sun, W.; Sun, T.; Gorris, L.G.M.; Wang, X.; Liu, B.; Dong, Q. The Prevalence of Listeria Monocytogenes in Meat Products in China: A Systematic Literature Review and Novel Meta-Analysis Approach. Int. J. Food Microbiol. 2020, 312, 108358. [Google Scholar] [CrossRef] [PubMed]
  24. Sun, T.; Liu, Y.; Aspridou, Z.; Zheng, J.; Wang, X.; Li, Z.; Dong, Q. The Prevalence and Epidemiology of Salmonella in Retail Raw Poultry Meat in China: A Systematic Review and Meta-Analysis. Foods 2021, 10, 2757. [Google Scholar] [CrossRef] [PubMed]
  25. Page, M.J.; Moher, D.; Bossuyt, P.M.; Boutron, I.; Hoffmann, T.C.; Mulrow, C.D.; Shamseer, L.; Tetzlaff, J.M.; Akl, E.A.; Brennan, S.E.; et al. The PRISMA 2020 Explanation and Elaboration: Updated Guidance and Examples for Reporting Systematic Reviews. BMJ 2021, 372, n160. [Google Scholar] [CrossRef] [PubMed]
  26. PRISMA 2020 Flow Diagram. Available online: https://www.prisma-statement.org/prisma-2020-flow-diagram (accessed on 5 September 2024).
  27. Higgins, J.P.T.; Thompson, S.G. Quantifying Heterogeneity in a Meta-analysis. Stat. Med. 2002, 21, 1539–1558. [Google Scholar] [CrossRef] [PubMed]
  28. Fakhri, Y.; Gasser, R.B.; Rostami, A.; Fan, C.K.; Ghasemi, S.M.; Javanian, M.; Bayani, M.; Armoon, B.; Moradi, B. Toxocara Eggs in Public Places Worldwide—A Systematic Review and Meta-Analysis. Environ. Pollut. 2018, 242, 1467–1475. [Google Scholar] [CrossRef] [PubMed]
  29. Dadar, M.; Fakhri, Y.; Shahali, Y.; Mousavi Khaneghah, A. Contamination of Milk and Dairy Products by Brucella Species: A Global Systematic Review and Meta-Analysis. Food Res. Int. 2020, 128, 108775. [Google Scholar] [CrossRef] [PubMed]
  30. Taghizadeh, M.; Nematollahi, A.; Bashiry, M.; Javanmardi, F.; Mousavi, M.; Hosseini, H. The Global Prevalence of Campylobacter spp. in Milk: A Systematic Review and Meta-Analysis. Int. Dairy J. 2022, 133, 105423. [Google Scholar] [CrossRef]
  31. El-Zamkan, M.A.; Abdel Hameed, K.G. Prevalence of Campylobacter jejuni and Campylobacter coli in Raw Milk and Some Dairy Products. Vet World 2016, 9, 1147–1151. [Google Scholar] [CrossRef] [PubMed]
  32. Bertasi, B.; Losio, M.N.; Daminelli, P.; Finazzi, G.; Serraino, A.; Piva, S.; Giacometti, F.; Massella, E.; Ostanello, F. Seasonal Variability of Thermophilic Campylobacter spp. in Raw Milk Sold by Automatic Vending Machines in Lombardy. Ital. J. Food Saf. 2016, 5, 5848. [Google Scholar] [CrossRef] [PubMed]
  33. Firstenberg-Eden, R.; Rosen, B.; Mannheim, C.H. Seasonal and Processing Influences on Bacterial Count of Raw and Processed Milk. J. Food Prot. 1979, 42, 683–685. [Google Scholar] [CrossRef] [PubMed]
  34. Liang, L.; Wang, P.; Zhao, X.; He, L.; Qu, T.; Chen, Y. Single-Molecule Real-Time Sequencing Reveals Differences in Bacterial Diversity in Raw Milk in Different Regions and Seasons in China. J. Dairy Sci. 2022, 105, 5669–5684. [Google Scholar] [CrossRef] [PubMed]
  35. Liu, X.-Y.; Hu, Q.; Xu, F.; Ding, S.-Y.; Zhu, K. Characterization of Bacillus cereus in Dairy Products in China. Toxins 2020, 12, 454. [Google Scholar] [CrossRef] [PubMed]
  36. Rezende-Lago, N.C.M.; Rossi, O.D., Jr.; Vidal-Martins, A.M.C.; Amaral, L.A. Occurrence of Bacillus Cereus in Whole Milk and Enterotoxigenic Potential of the Isolated Strains. Arq. Bras. Med. Vet. Zootec. 2007, 59, 1563–1569. [Google Scholar] [CrossRef]
  37. Kumari, S.; Sarkar, P.K. Bacillus Cereus Hazard and Control in Industrial Dairy Processing Environment. Food Control 2016, 69, 20–29. [Google Scholar] [CrossRef]
  38. Lesley, M.B.; Velnetti, L.; Yousr, A.N.; Kasing, A.; Samuel, L. Presence of Bacillus Cereus s.l. from Ready-to-Eat Cereals (RTE) Products in Sarawak. Int. Food Res. J. 2013, 20, 1031–1034. [Google Scholar]
  39. Kim, J.-B.; Choi, O.-K.; Kwon, S.-M.; Cho, S.-H.; Park, B.-J.; Jin, N.Y.; Yu, Y.M.; Oh, D.-H. Prevalence and Toxin Characteristics of Bacillus thuringiensis Isolated from Organic Vegetables. J. Microbiol. Biotechnol. 2017, 27, 1449–1456. [Google Scholar] [CrossRef] [PubMed]
  40. Fox, P.F.; McSweeney, P.L.H. Cheese: An Overview. In Cheese: Chemistry, Physics and Microbiology; Fox, P.F., McSweeney, P.L.H., Cogan, T.M., Guinee, T.P., Eds.; General Aspects; Academic Press: Cambridge, MA, USA, 2004; Volume 1, pp. 1–18. [Google Scholar] [CrossRef]
  41. Button, J.E.; Dutton, R.J. Cheese Microbes. Curr. Biology 2012, 22, R587–R589. [Google Scholar] [CrossRef] [PubMed]
  42. Zhao, Z.; Ning, C.; Chen, L.; Zhao, Y.; Yang, G.; Wang, C.; Chen, N.; Zhang, Z.; Li, S. Impacts of Manufacture Processes and Geographical Regions on the Microbial Profile of Traditional Chinese Cheeses. Food Res. Int. 2021, 148, 110600. [Google Scholar] [CrossRef] [PubMed]
  43. FSANZ. Microbiological Risk Assessmet of Raw Cow Milk. Risk Assessment Microbiology Section. Available online: https://www.foodstandards.gov.au/sites/default/files/food-standards-code/proposals/Documents/P1007%20PPPS%20for%20raw%20milk%201AR%20SD1%20Cow%20milk%20Risk%20Assessment.pdf (accessed on 5 June 2025).
  44. Ruwer, C.M.; de Moura, J.F.; Gonçalves, M.J.F. Outbreaks of Foodborne Diseases in Manaus, Amazonas (2005–2009): The Problem of Cheese Curd. Segurança Aliment. E Nutr. 2011, 18, 60–66. [Google Scholar] [CrossRef]
  45. Amenu, K.; Wieland, B.; Szonyi, B.; Grace, D. Milk Handling Practices and Consumption Behavior among Borana Pastoralists in Southern Ethiopia. J. Health Popul. Nutr. 2019, 38, 6. [Google Scholar] [CrossRef] [PubMed]
  46. Keba, A.; Rolon, M.L.; Tamene, A.; Dessie, K.; Vipham, J.; Kovac, J.; Zewdu, A. Review of the Prevalence of Foodborne Pathogens in Milk and Dairy Products in Ethiopia. Int. Dairy J. 2020, 109, 104762. [Google Scholar] [CrossRef]
  47. Zastempowska, E.; Grajewski, J.; Twarużek, M. Food-Borne Pathogens and Contaminants in Raw Milk—A Review. Ann. Anim. Sci. 2016, 16, 623–639. [Google Scholar] [CrossRef]
  48. Peng, Z.; Li, Y.; Yan, L.; Yang, S.; Yang, D. Correlation Analysis of Microbial Contamination and Alkaline Phosphatase Activity in Raw Milk and Dairy Products. Int. J. Environ. Res. Public Health 2023, 20, 1825. [Google Scholar] [CrossRef] [PubMed]
  49. Aleksic, B.; Djekic, I.; Miocinovic, J.; Miloradovic, Z.; Savic-Radovanovic, R.; Zdravkovic, N.; Smigic, N. The Hygienic Assessment of Dairy Products’ Selling Places at Open Markets. Food Control 2023, 148, 109628. [Google Scholar] [CrossRef]
  50. Mitchell, R. Aseptic and other designs that extend the shelf life of dairy products are driving functionality and efficiency. Dairy Foods 2023, 124, 12. [Google Scholar]
  51. Bennett, S.D.; Walsh, K.A.; Gould, L.H. Foodborne Disease Outbreaks Caused by Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus—United States, 1998–2008. Clin. Infect. Dis. 2013, 57, 425–433. [Google Scholar] [CrossRef]
  52. Liu, J.; Bai, L.; Li, W.; Han, H.; Fu, P.; Ma, X.; Bi, Z.; Yang, X.; Zhang, X.; Zhen, S.; et al. Trends of Foodborne Diseases in China: Lessons from Laboratory-Based Surveillance since 2011. Front. Med. 2018, 12, 48–57. [Google Scholar] [CrossRef] [PubMed]
  53. EFSA; ECDC. The European Union Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents and Food-Borne Outbreaks in 2013. EFSA J. 2015, 13, 3991. [Google Scholar] [CrossRef]
  54. Schoeni, J.L.; Lee Wong, A.C. Bacillus Cereus Food Poisoning and Its Toxins. J. Food Prot. 2005, 68, 636–648. [Google Scholar] [CrossRef] [PubMed]
  55. From, C.; Hormazabal, V.; Granum, P.E. Food Poisoning Associated with Pumilacidin-Producing Bacillus Pumilus in Rice. Int. J. Food Microbiol. 2007, 115, 319–324. [Google Scholar] [CrossRef] [PubMed]
  56. Apetroaie-Constantin, C.; Mikkola, R.; Andersson, M.A.; Teplova, V.; Suominen, I.; Johansson, T.; Salkinoja-Salonen, M. Bacillus subtilis and B. mojavensis Strains Connected to Food Poisoning Produce the Heat Stable Toxin Amylosin. J. Appl. Microbiol. 2009, 106, 1976–1985. [Google Scholar] [CrossRef] [PubMed]
  57. Scheldeman, P.; Herman, L.; Foster, S.; Heyndrickx, M. Bacillus sporothermodurans and Other Highly Heat-resistant Spore Formers in Milk. J. Appl. Microbiol. 2006, 101, 542–555. [Google Scholar] [CrossRef] [PubMed]
  58. Huemer, I.A.; Klijn, N.; Vogelsang, H.W.J.; Langeveld, L.P.M. Thermal Death Kinetics of Spores of Bacillus sporothermodurans Isolated from UHT Milk. Int. Dairy J. 1998, 8, 851–855. [Google Scholar] [CrossRef]
  59. Alonso, V.P.P.; de Oliveira Morais, J.; Kabuki, D.Y. Incidence of Bacillus cereus, Bacillus sporothermodurans and Geobacillus stearothermophilus in Ultra-High Temperature Milk and Biofilm Formation Capacity of Isolates. Int. J. Food Microbiol. 2021, 354, 109318. [Google Scholar] [CrossRef] [PubMed]
  60. Lazcka, O.; Campo, F.J.D.; Muñoz, F.X. Pathogen Detection: A Perspective of Traditional Methods and Biosensors. Biosens. Bioelectron. 2007, 22, 1205–1217. [Google Scholar] [CrossRef] [PubMed]
  61. Baraketi, A.; Salmieri, S.; Lacroix, M.; Baraketi, A.; Salmieri, S.; Lacroix, M. Foodborne Pathogens Detection: Persevering Worldwide Challenge. In Biosensing Technologies for the Detection of Pathogens—A Prospective Way for Rapid Analysis; Rinken, T., Kivirand, K., Eds.; IntechOpen: London, UK, 2018. [Google Scholar] [CrossRef]
  62. Razzuoli, E.; Vencia, W.; Fedele, V.; Mignone, G.; Lazzara, F.; Rubini, D.; Vito, G.; Porcario, C.; Bozzetta, E.; Ferrari, A. Evaluation and Validation of an Alternative Method to Detect Campylobacter spp. in Dairy Products. Ital. J. Food Safety 2018, 7, 89–94. [Google Scholar] [CrossRef] [PubMed]
Foods 14 02599 g001
Figure 1. Flowchart of the literature search and data collection process.
Figure 1. Flowchart of the literature search and data collection process.
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Figure 2. Worldwide distribution of Bacillus species by continents.
Figure 2. Worldwide distribution of Bacillus species by continents.
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Figure 3. Distribution of Bacillus species across different types of milk and dairy products isolated from farms (a), dairy plants (b), and retail markets (c).
Figure 3. Distribution of Bacillus species across different types of milk and dairy products isolated from farms (a), dairy plants (b), and retail markets (c).
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Table 1. Summarized information of the meta-analysis of Bacillus spp. prevalence in dairy products.
Table 1. Summarized information of the meta-analysis of Bacillus spp. prevalence in dairy products.
Total Included StudyTotal InputsTotal Sample SizePooled Prevalence (95% CI) aτ2 bI2 c
14241754,77211.8% (10.1–13.7%)2.960094.80%
a 95% CI: 95% confidence interval; b τ2: between-study variance; c I2: inverse variance index.
Table 2. Prevalence and sample size of Bacillus spp. by continent.
Table 2. Prevalence and sample size of Bacillus spp. by continent.
ContinentsTotal InputsTotal Sample SizePooled Prevalence (95% CI) aτ2 bI2 c
Asia13413,95315.4% (12.3–19.1%)2.120792.30%
Africa31225213.9% (9.3–20.3%)1.454286.20%
Europe11012,84111.4% (8.2–15.6%)3.425594.90%
America12319,09610.2% (7.5–13.7%)3.181595.60%
Oceania1328773.5% (3.3–3.7%)5.450196.00%
Unknown637533.1% (0.5–16.0%)4.859298.80%
a 95% CI: 95% confidence interval; b τ2: between-study variance; c I2: inverse variance index.
Table 3. Prevalence and sample size of Bacillus spp. by different types of samples from different sources.
Table 3. Prevalence and sample size of Bacillus spp. by different types of samples from different sources.
Sampling SiteSample TypeTotal InputsTotal Sample SizePooled Prevalence(95% CI) aτ2 bI2 c
FarmLiquid milk7796067.6% (5.1–11.2%)3.301494.40%
Cheese210520.8% (7.3–46.7%)0.615790.30%
Milk powder13073.3% (55.0–86.1%)--
Other dairy products1270.0%--
Environmental sample1290645.5% (20.1–72.8%)4.049394.00%
Total/9310,67410.3% (6.9–15.0%)4.161494.60%
Dairy plantLiquid milk7694928.6% (6.0–12.2%)2.455294.70%
Cheese1586524.2% (10.7–46.0%)3.530394.60%
Milk powder4913,3565.9% (3.3–10.5%)4.374897.10%
Ice cream1240.0%--
Concentrated milk920914.6% (8.2–24.4%)0.536760.50%
Other dairy products1158419.7% (9.1–37.6%)2.068190.30%
Environmental sample632113.4% (3.9–37.0%)2.341793.20%
Total/16724,8519.2% (7.1–12.0%)3.225695.40%
Retail Liquid milk60417116.4% (12.0–22.1%)1.855388.90%
Cheese35285317.6% (12.7–23.7%)1.122385.50%
Milk powder26447212.9% (7.0–22.4%)2.766396.70%
Ice cream6101244.2% (28.3–61.4%)0.645688.70%
Other dairy products15270810.9% (4.7–23.2%)3.011593.20%
Total/14215,21616.1% (13.0–19.7%)2.020393.50%
a 95% CI: 95% confidence interval; b τ2: between-study variance; c I2: inverse variance index.
Table 4. Prevalence and sample size of Bacillus spp. by microbial species.
Table 4. Prevalence and sample size of Bacillus spp. by microbial species.
SpeciesTotal InputsTotal Sample SizePooled Prevalence (95% CI) aτ2 bI2 c
Bacillus cereus21021,83719.8% (16.6–23.3%)2.239493.50%
Bacillus licheniformis32602726.3% (16.0–40.1%)3.101594.40%
Bacillus pumilus2541653.1% (1.6–5.9%)2.289188.10%
Bacillus safensis53113.6% (1.4–9.2%)0.694864.60%
Bacillus subtilis3151845.3% (3.4–8.2%)1.428191.40%
Bacillus altitudinis32321.7% (0.7–4.5%)0.00000.00%
Bacillus mojavensis21351.5% (0.4–5.7%)0.00000.00%
Bacillus wiedmannii1663.0% (0.8–11.3%)--
Bacillus weihenstephanensis1661.5% (0.2–1.0%)--
Bacillus zhangzhouensis1663.0% (0.7–11.3%)--
Bacillus paramycoides1666.1% (2.3–15.1%)--
Bacillus sonorensis39065.7% (2.4–12.9%)0.497490.30%
Bacillus circulans612123.4% (0.7–14.6%)3.375395.10%
Bacillus coagulans711023.1% (1.0–9.0%)1.772488.90%
Bacilus weithenstephanensis1831.2% (0.2–8.1%)--
Bacillus amyloliquefaciens25817.2% (9.5–29.2%)0.00000.00%
Bacillus thuringiensis33214.52% (0.65–25.5%)2.542288.40%
Bacillus mycoides21693.6% (1.4–8.8%)0.124160.10%
Bacillus megaterium47592.9% (1.8–4.7%)0.044932.10%
Bacillus lentus31952.1% (0.8–5.3%)0.00000.00%
Bacillus sporothermodurans448336.5% (21.8–54.3%)0.502495.00%
Bacillus clausii715702.4% (1.0–5.8%)1.041870.70%
Bacillus brevis324010.2% (2.2–37.1%)1.857792.20%
Bacillus paralicheniformis11140.9% (0.1–6.0%)--
Bacillus toyonesis11141.8% (0.4–6.7%)--
Bacillus invictae11140.9% (0.1–6.0%)--
Bacillus thermoamylovorans515232.5% (0.5–11.3%)2.633088.00%
Bacillus simplex1224.6% (0.6–26.2%)--
Bacillus fusiformis1698.7% (4.0–18.0%)--
Bacillus sphaericus11110.9% (0.1–6.1%)--
Bacillus macerans11110.9% (0.1–6.1%)--
Bacillus firmus11110.9% (0.1–6.1%)--
Bacillus polymyxa11111.8% (0.5–7.0%)--
Bacillus stearothermophilus11112.7% (0.9–8.0%)--
Bacillus aerophilus1224.6% (0.6–26.2%)--
Other Bacillus44698611.9% (7.8–17.6%)2.139295.30%
a 95% CI: 95% confidence interval; b τ2: between-study variance; c I2: inverse variance index.
Table 5. Prevalence and sample size of Bacillus spp. by detection method.
Table 5. Prevalence and sample size of Bacillus spp. by detection method.
Detection MethodTotal InputsTotal Sample SizePooled Prevalence (95% CI) aτ2 bI2 c
Culture–biochemical22234,5729.2% (7.4–11.3%)2.832095.50%
Culture–molecular16517,42816.6% (13.1–20.8%)3.034293.70%
Culture–biochemical–molecular30277210.8% (6.6–17.0%)1.954891.00%
a 95% CI: 95% confidence interval; b τ2: between-study variance; c I2: inverse variance index.
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Sun, T.; Wang, R.; Sun, Y.; Zhang, X.; Ge, C.; Li, Y. The Global Prevalence of Bacillus spp. in Milk and Dairy Products: A Systematic Review and Meta-Analysis. Foods 2025, 14, 2599. https://doi.org/10.3390/foods14152599

AMA Style

Sun T, Wang R, Sun Y, Zhang X, Ge C, Li Y. The Global Prevalence of Bacillus spp. in Milk and Dairy Products: A Systematic Review and Meta-Analysis. Foods. 2025; 14(15):2599. https://doi.org/10.3390/foods14152599

Chicago/Turabian Style

Sun, Tianmei, Ran Wang, Yanan Sun, Xiaoxu Zhang, Chongtao Ge, and Yixuan Li. 2025. "The Global Prevalence of Bacillus spp. in Milk and Dairy Products: A Systematic Review and Meta-Analysis" Foods 14, no. 15: 2599. https://doi.org/10.3390/foods14152599

APA Style

Sun, T., Wang, R., Sun, Y., Zhang, X., Ge, C., & Li, Y. (2025). The Global Prevalence of Bacillus spp. in Milk and Dairy Products: A Systematic Review and Meta-Analysis. Foods, 14(15), 2599. https://doi.org/10.3390/foods14152599

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