Search Results (17)

Objectives: This observational and cross-sectional study investigated differential associations between entero-invasive and non-entero-invasive enteric pathogens and HIV infection, considering socioeconomic, clinical and immunological aspects. In a Ghanaian population with a high prevalence of enteric pathogens, stool samples from people living with HIV (PLWH) were screened for Salmonella spp., Shigella spp./EIEC (enteroinvasive Escherichia coli), and Campylobacter jejuni as entero-invasive bacteria, for enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC) as non-entero-invasive bacteria. Arcobacter butzleri, with uncertain enteropathogenicity, was also included. Methods: Stool samples from PLWH (with and without antiretroviral therapy) and HIV-negative controls were analyzed by real-time PCR for the presence and quantity of the selected enteropathogens. Results were correlated with socioeconomic, clinical, and immunological parameters. Results: The presence of Shigella spp. /EIEC in stool was both qualitatively and quantitatively associated with reduced CD4+ T lymphocyte counts and was qualitatively associated with clinically apparent diarrhea. EAEC showed a weak positive association with HIV infection, supported by a negative correlation between EAEC DNA quantity and CD4+ T lymphocyte counts. EPEC colonization was associated with HIV negativity, higher CD4+ T lymphocyte counts, and lower socioeconomic status. Abundance of Salmonella enterica was associated with clinically apparent diarrhea. Conclusions: This explorative, hypothesis-forming study suggests species- or pathovar-specific associations between enteric bacterial pathogens and HIV-related immunosuppression. Observed relationships with clinically apparent diarrhea largely align with findings from sub-Saharan African children, except for a more pronounced association between diarrhea and Salmonella in this cohort. Full article

Campylobacter spp. and Arcobacter spp. are recognized etiological agents of gastroenteritis worldwide. While poultry is their best-known reservoir, human exposure can also occur via environmental pathways, particularly through contaminated water sources, which play a significant role in their transmission dynamics. In addition to their pathogenicity and widespread environmental prevalence, increasing antibiotic resistance has contributed to the global emergence of multidrug-resistant strains, hindering effective treatment. Here, the distribution and antibiotic resistance potential of Campylobacter spp. and Arcobacter spp. isolates collected from water bodies in Portugal were investigated. Water samples were collected from rivers, their tributaries, and springs, at 25 sites over a six-month period. Campylobacter spp. were isolated from 13.3% of the samples, whereas Arcobacter spp. were detected in 57.6% of the samples. Of the 27 isolated Campylobacter isolates, 44.0% were resistant to at least one antibiotic, while only one strain exhibited a multidrug-resistant (MDR) phenotype. In contrast, 98.9% of the 177 Arcobacter isolates were resistant to at least one antibiotic, with 15.8% classified as MDR. These findings contribute to the surveillance of Campylobacter spp. and Arcobacter spp., highlighting the critical role of aquatic environments in their epidemiology and supporting the need to incorporate waterborne transmission pathways into integrated surveillance and control strategies within the One Health framework. Full article

The consumption of fresh fruit and vegetables is essential for a healthy diet as they contain a diverse composition of vitamins, minerals, fibre, and bioactive compounds. However, cross-contamination during harvest and post-harvest poses a high risk of microbial contamination. Therefore, handling fruit and vegetables during processing and contact with wet equipment and utensil surfaces is an ideal environment for microbial contamination and foodborne illness. Nevertheless, less attention has been paid to some emerging pathogens that are now increasingly recognised as transmissible to humans through contaminated fruit and vegetables, such as Arcobacter and Cronobacter species in various products, which are the main risk in fruit and vegetables. Cronobacter and Arcobacter spp. are recognised food-safety hazards because they pose a risk of foodborne disease, especially in vulnerable groups such as newborns and immunocompromised individuals. Cronobacter spp. have been linked to severe infant conditions—notably meningitis and sepsis—most often traced to contaminated powdered infant formula. Although Arcobacter spp. have been less extensively studied, they have also been associated with foodborne disease, chiefly from dairy products and meat. With this in mind, this review provides an overview of the main chemical and physical sanitisation methods in terms of their ability to reduce the contamination of fresh fruit and vegetable products caused by two emerging pathogens: Arcobacter and Cronobacter. Emerging chemical (organic acid compounds, extracts, and essential oils) and physical methods (combination of UV-C with electrolysed water, ultrasound, and cold atmospheric plasma) offer innovative and environmentally friendly alternatives to traditional approaches. These methods often utilise natural materials, less toxic solvents, and novel techniques, resulting in more sustainable processes compared with traditional methods that may use harsh chemicals and environmentally harmful processes. This review provides the fruit and vegetable industry with a general overview of possible decontamination alternatives to develop optimal and efficient processes that ensure food safety. Full article

This study aimed to isolate and genetically characterize Arcobacter species from broiler chickens sampled at three slaughterhouses in Grenada, West Indies. A total of 126 samples—including cloacal swabs, intestinal contents, and meat—from 42 birds were cultured using a chromogenic agar medium. Arcobacter spp. were detected in 21.4% (9/42) of the birds. Among the sample types, meat exhibited the highest prevalence at 14.3% (6/42), followed by fecal samples at 7.1% (3/42) and cloacal swabs at 2.4% (1/42). Genus- and species-specific polymerase chain reaction assays on 33 isolates identified five Arcobacter species: A. butzleri, A. cryaerophilus, and A. skirrowii (each 18.2%), as well as A. cibarius and A. thereius (each 6.1%). Genetic diversity was further assessed via Enterobacterial Repetitive Intergenic Consensus–polymerase chain reaction, which revealed 13 distinct genotypic fingerprints forming six clusters, with a high discriminatory power (D = 0.96). This study represents the first documented isolation and molecular characterization of five Arcobacter species from broiler chickens in Grenada across multiple sample types. These findings underscore the zoonotic implications of isolating Arcobacter spp., particularly in contaminated poultry meat destined for human consumption. The presence of Arcobacter spp. in poultry carcasses poses a significant public health concern. To mitigate this public health risk, recommendations include surveillance for the presence of this pathogen in Hazard Analysis and Critical Control Points plans or other tools used to identify pathogens compromising food safety and public health. Full article

Investigating human pathogens in wastewater is crucial for identifying and predicting potential occupational health risks faced by wastewater treatment plant (WWTP) workers. This study aimed to determine the occurrence and levels of Legionella pneumophila, Mycobacterium spp., Arcobacter butzleri, and Aeromonas hydrophila in untreated municipal wastewater. Grab influent, activated sludge, and secondary settling tank (SST) effluent samples were collected bi-weekly over 6 months from 5 WWTPs in Tshwane, South Africa. Mycobacterium spp., A. butzleri, and A. hydrophila were detected using quantitative PCR (qPCR), while Legionella was detected using both a culture method and qPCR. The four pathogens were identified in most samples at varying levels. Legionella pneumophila had a positivity rate of 92%, ranging from 2 to 5.4 log₁₀ MPN/100 mL. Detection rates of Legionella spp., L. pneumophila, and L. pneumophila serogroup 1 were 97%, 75%, and 69%, respectively, with up to 5.3 log₁₀ gene copies (GC)/mL. Importantly, this study demonstrates molecular typing of L. pneumophila serogroup 1 in wastewater, a topic that has been rarely documented. Mycobacterium spp. were detected in all samples at varying levels (log₁₀ GC/mL) in influent (2.8–7.6), activated sludge (4.8–8.9), and SST effluent (3.8–8.9) samples. Arcobacter butzleri and A. hydrophila were detected in 96% and 82% of the samples, respectively, with GC levels in influent, activated sludge, and SST effluent ranging from 0.8 to 6.6, 1.5 to 6.5, and 0.7 to 6.6 log₁₀ GC/mL for A. butzleri, and similar levels for A. hydrophila. These findings underscore the presence of respiratory and enteric pathogens at various treatment points, suggesting potential occupational exposure for WWTP workers. This emphasises the need for microbiological risk assessments (RAs) or reviewing existing RAs and implementing necessary control measures to protect WWTP workers. Full article

Background: In recent years, significant resistance of microorganisms to antibiotics has been observed. A biofilm is a structure that significantly aids the survival of the microbial population and also significantly affects its resistance. Methods: Thyme and clove essential oils (EOs) were subjected to chemical analysis using gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID). Furthermore, the antimicrobial effect of these EOs was tested in both the liquid and vapor phases using the volatilization method. The effect of the EOs on growth parameters was monitored using an RTS-8 bioreactor. However, the effect of the EOs on the biofilm formation of commonly occurring bacteria with pathogenic potential was also monitored, but for less described and yet clinically important strains of Arcobacter spp. Results: In total, 37 and 28 compounds were identified in the thyme and clove EO samples, respectively. The most common were terpenes and also derivatives of phenolic substances. Both EOs exhibited antimicrobial activity in the liquid and/or vapor phase against at least some strains. The determined antimicrobial activity of thyme and clove oil was in the range of 32–1024 µg/mL in the liquid phase and 512–1024 µg/mL in the vapor phase, respectively. The results of the antimicrobial effect are also supported by similar conclusions from monitoring growth curves using the RTS bioreactor. The effect of EOs on biofilm formation differed between strains. Biofilm formation of Pseudomonas aeruginosa was completely suppressed in an environment with a thyme EO concentration of 1024 µg/mL. On the other hand, increased biofilm formation was found, e.g., in an environment of low concentration (1–32 µg/mL). Conclusions: The potential of using natural matrices as antimicrobials or preservatives is evident. The effect of these EOs on biofilm formation, especially Arcobacter strains, is described for the first time. Full article

The Arcobacteraceae bacterial family includes species isolated from animals and related food products. Moreover, these species have been found in other ecological niches, including water. Some species, particularly Arcobacter butzleri and Arcobacter cryaerophilus, have been isolated from human clinical cases and linked to gastrointestinal symptoms. The presence of antibiotic-resistant strains is a concern for public health, considering the possible zoonoses and foodborne infections caused by contaminated food containing bacteria resistant to antibiotic treatments. This review aims to highlight the importance of antibiotic resistance in Arcobacter spp. isolates from several sources, including information about antibiotic classes to which this bacterium has shown resistance. Arcobacter spp. demonstrated a wide spectrum of antibiotic resistance, including several antibiotic resistance genes. Antibiotic resistance genomic traits include efflux pumps and mutations in antibiotic target proteins. The literature shows a high proportion of Arcobacter spp. that are multidrug-resistant. However, studies in the literature have primarily focused on the evaluation of antibiotic resistance in A. butzleri and A. cryaerophilus, as these species are frequently isolated from various sources. These aspects underline the necessity of studies focused on several Arcobacter species that could potentially be isolated from several sources. Full article

Bivalves can concentrate biological and chemical pollutants, causing foodborne outbreaks whose occurrence is increasing, due to climatic and anthropic factors that are difficult to reverse, hence the need for improved surveillance. This study aimed to evaluate the hygienic qualities of bivalves sampled along the production and distribution chain in Sicily and collect useful data for consumer safety. Bacteriological and molecular analyses were performed on 254 samples of bivalves for the detection of enteropathogenic Vibrio, Arcobacter spp., Aeromonas spp., Salmonella spp., and beta-glucuronidase-positive Escherichia coli. A total of 96 out of 254 samples, collected in the production areas, were processed for algal biotoxins and heavy metals detection. Bacterial and algal contaminations were also assessed for 21 samples of water from aquaculture implants. Vibrio spp., Arcobacter spp., Aeromonas hydrophila, Salmonella spp., and Escherichia coli were detected in 106/254, 79/254, 12/254, 16/254, and 95/254 molluscs, respectively. A total of 10/96 bivalves tested positive for algal biotoxins, and metals were under the legal limit. V. alginolyticus, A. butzleri, and E. coli were detected in 5, 3, and 3 water samples, respectively. Alexandrium minutum, Dinophysis acuminata, Lingulodinium polyedra, and Pseudonitzschia spp. were detected in water samples collected with the biotoxin-containing molluscs. Traces of yessotoxins were detected in molluscs from water samples containing the corresponding producing algae. Despite the strict regulation by the European Commission over shellfish supply chain monitoring, our analyses highlighted the need for efficiency improvement. Full article

In response to growing global interest in organic agriculture, this study delves into the microbial landscape of organically grown raw produce with a focus on food safety. Vegetables that are consumed raw are potential vehicles for the transmission of any type of microorganism capable of causing human disease. Free-living amoebae (FLA) are ubiquitous protozoa found in many ecosystems and can serve as hosts to pathogenic bacteria. So far, data regarding the FLA bacterial microbiome in fresh produce remain scarce and are non-existent for those of organic origin. Thus, the aim of this preliminary work is to characterize the microbiome of FLA in commonly consumed raw vegetables to know their possible implications for consumers. A total of 40 organic cabbage, lettuce, spinach, and strawberry samples were analyzed. FLA were found in all samples, and their bacterial microbiome was obtained via amplicon sequencing using the Illumina MiSeq platform and pair-end protocol. Acanthamoeba spp. and Vermamoeba vermiformis were identified via qPCR in 65.0% and 25.0% of the samples, respectively. Regarding the bacterial microbiome of FLA, the most abundant genera were Pseudomonas (1.8–17.8%) and Flavobacterium (1.7–12.6%). Bacteria not previously related to FLA, such as Prosthecobacter or Cellvibrio, are described in this work. Importantly, several bacterial genera found within the FLA microbiome were identified as potential human pathogens, including Pseudomonas, Flavobacterium, Arcobacter, Klebsiella, Mycobacterium, Salmonella and Legionella. This is the first work in which FLA microbiome isolated from organic products has been characterized, underscoring the significance of understanding FLA’s role as carriers of pathogenic bacteria in the context of organic food safety. Full article

Wastewater storage before reuse is regulated in some countries. Investigations of pathogens and antibiotic resistance genes (ARGs) during wastewater storage are necessary for lowering the risks for wastewater reuse but are still mostly lacking. This study aimed to investigate pathogens, including harmful plant pathogens, and ARGs during 180 d of swine wastewater (SWW) storage in an anaerobic storage experiment. The contents of total organic carbon and total nitrogen in SWW were found to consistently decrease with the extension of storage time. Bacterial abundance and fungal abundance significantly decreased with storage time, which may be mainly attributed to nutrient loss during storage and the long period of exposure to a high level (4653.2 μg/L) of sulfonamides in the SWW, which have an inhibitory effect. It was found that suspected bacterial pathogens (e.g., Escherichia–Shigella spp., Vibrio spp., Arcobacter spp., Clostridium_sensu_stricto_1 spp., and Pseudomonas spp.) and sulfonamide-resistant genes Sul1, Sul2, Sul3, and SulA tended to persist and even become enriched during SWW storage. Interestingly, some suspected plant fungal species (e.g., Fusarium spp., Ustilago spp. and Blumeria spp.) were detected in SWW. Fungi in the SWW, including threatening fungal pathogens, were completely removed after 60 d of anaerobic storage, indicating that storage could lower the risk of using SWW in crop production. The results clearly indicate that storage time is crucial for SWW properties, and long periods of anaerobic storage could lead to substantial nutrient loss and enrichment of bacterial pathogens and ARGs in SWW. Full article

Campylobacter jejuni is the most frequent cause of bacterial gastrointestinal food-borne infection worldwide. The transmission of Campylobacter and Arcobacter-like species is often made possible by their ability to adhere to various abiotic surfaces. This study is focused on monitoring the biofilm ability of 69 strains of Campylobacter spp. and lesser described species of the Arcobacteraceae family isolated from food, water, and clinical samples within the Czech Republic. Biofilm formation was monitored and evaluated under an aerobic/microaerophilic atmosphere after cultivation for 24 or 72 h depending on the surface material. An overall higher adhesion ability was observed in arcobacters. A chi-squared test showed no association between the origin of the strains and biofilm activity (p > 0.05). Arcobacter-like species are able to form biofilms under microaerophilic and aerobic conditions; however, they prefer microaerophilic environments. Biofilm formation has already been demonstrated at refrigerator temperatures (5 °C). Arcobacters also showed higher biofilm formation ability at the temperature of 30 °C. This is in contrast to Campylobacter jejuni NP 2896, which showed higher biofilm formation ability at temperatures of 5–30 °C. Overall, the results demonstrated the biofilm formation ability of many strains, which poses a considerable risk to the food industry, medical practice, and human health. Full article

Sea urchins, in many instances, are collected from the wild, maintained in the laboratory aquaculture environment, and used as model animals for various scientific investigations. It has been increasingly evident that diet-driven dysbiosis of the gut microbiome could affect animal health and physiology, thereby impacting the outcome of the scientific studies. In this study, we compared the gut microbiome between naturally occurring (ENV) and formulated diet-fed laboratory aquaculture (LAB) sea urchin Lytechinus variegatus by amplicon sequencing of the V4 region of the 16S rRNA gene and bioinformatics tools. Overall, the ENV gut digesta had higher taxa richness with an abundance of Propionigenium, Photobacterium, Roseimarinus, and Flavobacteriales. In contrast, the LAB group revealed fewer taxa richness, but noticeable abundances of Arcobacter, Agarivorans, and Shewanella. However, Campylobacteraceae, primarily represented by Arcobacter spp., was commonly associated with the gut tissues of both ENV and LAB groups whereas the gut digesta had taxa from Gammaproteobacteria, particularly Vibrio spp. Similarly, the co-occurrence network displayed taxonomic organizations interconnected by Arcobacter and Vibrio as being the key taxa in gut tissues and gut digesta, respectively. Predicted functional analysis of the gut tissues microbiota of both ENV and LAB groups showed a higher trend in energy-related metabolisms, whereas amino acids, carbohydrate, and lipid metabolisms heightened in the gut digesta. This study provides an outlook of the laboratory-formulated diet-fed aquaculture L. variegatus gut microbiome and predicted metabolic profile as compared to the naturally occurring animals, which should be taken into consideration for consistency, reproducibility, and translatability of scientific studies. Full article

Arcobacter spp. are emerging waterborne and foodborne zoonotic pathogens responsible for gastroenteritis in humans. In this work, we evaluated the occurrence and the antimicrobial resistance profile of Arcobacter isolates recovered from different aquatic sources. Besides, we searched for Arcobacter spp. in seaweeds and the corresponding seawater samples. Bacteriological and molecular methods applied to 100 samples led to the isolation of 28 Arcobacter isolates from 27 samples. The highest prevalence was detected in rivers followed by artificial ponds, streams, well waters, and spring waters. Seaweeds contained a higher percentage of Arcobacter than the corresponding seawater samples. The isolates were identified as Arcobacter butzleri (96.4%) and Arcobacter cryaerophilus (3.6%). All the isolates showed a multi-drug resistance profile, being resistant to at least three different classes of antibiotics. Molecular analysis of genetic determinants responsible for tetracycline resistance in nine randomly chosen isolates revealed the presence of tetO and/or tetW. This work confirms the occurrence and the continuous emergence of antibiotic-resistant Arcobacter strains in environmental samples; also, the presence of quinolone-resistant Arcobacter spp. in aquatic sources used for water supply and irrigation represents a potential risk for human health. Full article

The evaluation of effluent wastewater quality mainly relies on the assessment of conventional bacterial indicators, such as fecal coliforms and enterococci; however, little is known about opportunistic pathogens, which can resist chlorination and may be transmitted in aquatic environments. In contrast to conventional microbiological methods, high-throughput molecular techniques can provide an accurate evaluation of effluent quality, although a limited number of studies have been performed in this direction. In this work, high-throughput amplicon sequencing was employed to assess the effectiveness of chlorination as a disinfection method for secondary effluents. Common inhabitants of the intestinal tract, such as Bacteroides, Arcobacter and Clostridium, and activated sludge denitrifiers capable of forming biofilms, such as Acidovorax, Pseudomonas and Thauera, were identified in the chlorinated effluent. Chloroflexi with dechlorination capability and the bacteria involved in enhanced biological phosphorus removal, i.e., Candidatus Accumulibacter and Candidatus Competibacter, were also found to resist chlorination. No detection of Escherichia indicates the lack of fecal coliform contamination. Mycobacterium spp. were absent in the chlorinated effluent, whereas toxin-producing cyanobacteria of the genera Anabaena and Microcystis were identified in low abundances. Chlorination significantly affected the filamentous bacteria Nocardioides and Gordonia, whereas Zoogloea proliferated in the disinfected effluent. Moreover, perchlorate/chlorate- and organochlorine-reducing bacteria resisted chlorination. Full article

Routine diagnostic methods for the aetiologic agents of diarrhoea in most developing countries are usually not sensitive enough, leading to under-diagnosis. Thus, this study investigated possible mixed diarrhoeal aetiology by using cultures and real-time polymerase chain reactions (PCR) in children younger than four years old in the Northwest Province, South Africa. In total, 505 stool samples were collected from symptomatic and asymptomatic children who were attending three clinics and the Brits hospital in Madibeng District, between September 2016 and December 2017. Rotavirus, norovirus, Campylobacter, Arcobacter, and diarrhoeagenic Escherichia coli (DEC) were targeted. Campylobacter spp. (24.6%), Arcobacter (15.8%) and DEC (19.6%) were detected using PCR; only Campylobacter spp. (29.7%) and DEC (26.9%) were detected through the culture. Campylobacter jejuni (36%), Campylobacter coli (28%), Campylobacter upsalensis (12%), and Arcobacter butzleri (15.8%) were the only spp. of Campylobacter and Arcobacter identified. The eaeA gene (31.4%) of enteropathogenic E. coli/enterohaemorrhagic E. coli (EPEC/EHEC) was the most prevalent DEC virulence gene (VG) identified. Rotavirus and norovirus were detected at 23.4% and 20%, respectively. Mixed viral aetiology (7.3%) and the co-infection of A. butzleri and Campylobacter (49%) were recorded. A mixed bacterial-viral aetiology was observed in 0.6% of the specimens. Sensitive diagnostic procedures like PCR should be considered to provide the best treatment to children experiencing diarrhoea. Full article