Microbiology Research

Research

16 pages, 1659 KiB

Open AccessArticle

Enhancing Diagnostic Resilience: Evaluation of Extraction Platforms and IndiMag Pathogen Kits for Rapid Animal Disease Detection

by Anne Vandenburg-Carroll, Douglas G. Marthaler and Ailam Lim

Microbiol. Res. 2025, 16(4), 80; https://doi.org/10.3390/microbiolres16040080 - 3 Apr 2025

Viewed by 228

Abstract

The United States is facing outbreaks of highly pathogenic avian influenza H5N1 in birds and dairy cattle, along with threats of African swine fever, classical swine fever, and foot-and-mouth disease. While the National Animal Health Laboratory Network (NAHLN) depends on high-throughput testing, the [...] Read more.

The United States is facing outbreaks of highly pathogenic avian influenza H5N1 in birds and dairy cattle, along with threats of African swine fever, classical swine fever, and foot-and-mouth disease. While the National Animal Health Laboratory Network (NAHLN) depends on high-throughput testing, the KingFisher Duo Prime, IndiMag 48s, and IndiMag 2 are viable alternatives to aid in outbreak assessments. This study evaluates extraction platforms and the IndiMag Pathogen Kit for detecting the previous listed pathogens. Samples and reference materials were extracted using the MagMAX Viral RNA Isolation Kit, MagMAX CORE Nucleic Acid Purification Kit, and IndiMag Pathogen Kit. Real-time RT-PCR was performed following NAHLN protocols to assess analytical and diagnostic performance. Comparable limits of detection across extraction chemistries, instrumentation, and pathogens were demonstrated, with PCR efficiency ranging between 82.5% and 107.6%. The precision variability was low, with the coefficient of variation ranging from 0.16% to 1.76%. Diagnostic sensitivity and specificity were 100%, with a kappa coefficient of 1.0, indicating strong agreement between methods. These findings support the KingFisher Duo Prime, IndiMag 48s, IndiMag 2, and IndiMag Pathogen Kits as reliable options for NAHLN-approved testing, increasing equipment and reagent alternatives to enhance diagnostic resilience and improve response capabilities to emerging animal health threats. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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10 pages, 1638 KiB

Open AccessCommunication

Microbiota of Punctuated Snake Eel Ophichthus remiger (Valenciennes, 1842) Reared in Recirculation System Is Dominated by Latilactobacillus

by Jaime Romero, Carolina Ramírez, Luz Hurtado, Edison Serrano and Rodrigo Rojas

Microbiol. Res. 2025, 16(2), 38; https://doi.org/10.3390/microbiolres16020038 - 5 Feb 2025

Viewed by 605

Abstract

Research on microbiota has underscored the crucial influence of microbial communities on numerous biological functions that yield positive outcomes for the host, such as digestion, nutrient metabolism, resistance against pathogen invasion, and growth performance. Concurrently, numerous variables, including the host’s diet, genetics, and [...] Read more.

Research on microbiota has underscored the crucial influence of microbial communities on numerous biological functions that yield positive outcomes for the host, such as digestion, nutrient metabolism, resistance against pathogen invasion, and growth performance. Concurrently, numerous variables, including the host’s diet, genetics, and physiological condition and environmental factors, influence the gut microbiota. Our study aims to characterize the bacterial community composition of the common snake eel (Ophichthus remiger), captured wild and then reared under controlled conditions. We employed a 16S rRNA gene-based approach facilitated by next-generation sequencing to conduct this analysis. The gut microbiota of the snake eel was highly dominated by bacteria from the phylum Firmicutes, comprising over 80% of the relative abundance, with Lactilactobacillus being the most important genus. The results suggest that feed-associated bacteria may influence the composition of the microbiota, contributing the most relevant bacteria within the intestinal content. This study provides the first comprehensive analysis of the gut microbiota in Ophichthus remiger, offering novel insights into the potential roles of Firmicutes and Lactilactobacillus in marine eels. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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12 pages, 2311 KiB

Open AccessArticle

Genomic Characterization of Laodelphax striatellus Permutotetra-like Virus and Self-Cleavage Function of Viral Capsid Protein

by Jun Piao, Jiarui Zhang, Lujie Zhang, Jingai Piao, Haitao Wang, Yilin Xie and Shuo Li

Microbiol. Res. 2025, 16(1), 9; https://doi.org/10.3390/microbiolres16010009 - 2 Jan 2025

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Abstract

Laodelphax striatellus permutotetra-like virus (LsPLV) is a novel insect virus identified via small RNA deep sequencing. At present, there is a lack of awareness of LsPLV, restricting research on its utilization in biocontrol. In this paper, the full-length genome of LsPLV was cloned [...] Read more.

Laodelphax striatellus permutotetra-like virus (LsPLV) is a novel insect virus identified via small RNA deep sequencing. At present, there is a lack of awareness of LsPLV, restricting research on its utilization in biocontrol. In this paper, the full-length genome of LsPLV was cloned and analyzed, then viral capsid protein (CP) was expressed and prepared as an antibody, and CP property was tested. It was found that the LsPLV genome was 4667 nt in length, encoding two proteins, RNA-dependent RNA polymerase (RdRP) and CP, and the palm subdomain conserved region in RdRp was arranged in a “C–A–B” permutation pattern, exhibiting the typical characteristics of permutotetra-like viruses. Phylogenetic analysis suggested that LsPLV shared the highest homology (excluding LsPLV1) with a Nodaviridae virus (QLI47702.1), and their nucleotide identities of RdRP and CP were 55.4% and 59.2%, respectively. After expression, purified CP exhibited two bands of 60 kDa and 47 kDa, suggesting a potential cleavage in the protein. LsPLV CP in L. striatellus was detected by Western blot, and except for the complete CP band, the specific bands with molecular weights lower than CP were also detected, indicating that CP underwent cleavage. Detection of purified CP in vitro showed that the cleavage could occur independent of any protease, confirming that CP has self-cleavage characteristics. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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16 pages, 9495 KiB

Open AccessArticle

Detection and Phylogenetic Analysis of Alphacoronaviruses in Bat Populations of Rostov and Novosibirsk Regions of Russia, 2021–2023

by Olesia V. Ohlopkova, Igor V. Popov, Ilia V. Popov, Kristina A. Stolbunova, Marina A. Stepanyuk, Alexey D. Moshkin, Aleksei A. Maslov, Ivan A. Sobolev, Aleksey V. Malinovkin, Elizaveta V. Tkacheva, Daria A. Bogdanova, Ekaterina A. Lukbanova, Alexey M. Ermakov, Alexander Y. Alekseev, Svetoslav D. Todorov and Alexander M. Shestopalov

Microbiol. Res. 2025, 16(1), 3; https://doi.org/10.3390/microbiolres16010003 - 29 Dec 2024

Viewed by 686

Abstract

Bats are natural reservoirs for many emerging viruses, including coronaviruses that were probably progenitors to human coronaviruses with epidemic and pandemic potential, which highlights the importance of screening studies of bat-derived viruses. This study investigates the prevalence and phylogenetic characteristics of coronaviruses in [...] Read more.

Bats are natural reservoirs for many emerging viruses, including coronaviruses that were probably progenitors to human coronaviruses with epidemic and pandemic potential, which highlights the importance of screening studies of bat-derived viruses. This study investigates the prevalence and phylogenetic characteristics of coronaviruses in bat populations from the Rostov and Novosibirsk regions of Russia between 2021 and 2023. Utilizing PCR screening and sequencing, viruses belonging to the Alphacoronavirus genus were detected in several bat species, with prevalence rates ranging from 4.94% to 62.5%. Phylogenetic analysis of detected sequences revealed the presence of three subgenera: Pedacovirus, Myotacovirus, and Nyctacovirus. These sequences shared over 90% identity with alphacoronaviruses previously identified in bats across Northern Europe and Russia, underscoring the viruses’ wide geographic distribution and evolutionary connections. The results highlight the adaptability of alphacoronaviruses and the role of bat migratory behavior in their dispersal. The study underscores the importance of continuous monitoring and phylogenetic studies of bat-derived coronaviruses to better understand their ecological dynamics and potential zoonotic threats. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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15 pages, 1369 KiB

Open AccessArticle

Blood Parasites (Haemosporida, Trypanosomatida) in Culex pipiens: A Study and Review of Hibernating and Active Mosquitoes

by Kristina Valavičiūtė-Pocienė, Margarita Kazak, Tatjana Iezhova, Gabrielė Kalinauskaitė and Rasa Bernotienė

Microbiol. Res. 2024, 15(4), 2184-2198; https://doi.org/10.3390/microbiolres15040146 - 25 Oct 2024

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Abstract

Culex pipiens mosquitoes (Diptera: Culicidae) are widespread during warm periods and actively feed on blood while serving as vectors for various human and animal pathogens. Culex mosquitoes overwinter as adults in temperate zones, raising the question of whether hibernating Cx. pipiens can act [...] Read more.

Culex pipiens mosquitoes (Diptera: Culicidae) are widespread during warm periods and actively feed on blood while serving as vectors for various human and animal pathogens. Culex mosquitoes overwinter as adults in temperate zones, raising the question of whether hibernating Cx. pipiens can act as pathogen reservoirs. In this study, hibernating mosquitoes and mosquitoes collected during the warm season were tested for the presence of trypanosomatids and avian haemosporidian parasites using PCR. Midgut preparations were made from Cx. pipiens females in order to search for trypanosomatids morphologically. In total, 1037 Cx. pipiens mosquitoes (556 collected during the warm season and 481 overwintering mosquitos) were investigated. The parasite prevalence differed for mosquitoes collected during the warm season and hibernating ones for both Haemosporida (2.9% in warm-season and no infections in overwintering mosquitoes) and Trypanosomatida (1.6% and 0.4%, respectively) parasites. A phylogenetic analysis confirmed that the trypanosomatids found in hibernating mosquitoes were monoxenous and were not parasites of vertebrates. The peak prevalence of Haemosporida parasites was detected in July (4.9%) and August (2.8%), and for Trypanosomatida, it was detected in May (3.5%). The results of the present study show that overwintering Cx. pipiens mosquitoes are questionable reservoirs for avian haemosporidian parasites, but some monoxenous trypanosomatids can be found in overwintering females. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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17 pages, 4777 KiB

Open AccessArticle

Development of a Quadruplex RT-qPCR for the Detection of Feline Kobuvirus, Feline Astrovirus, Feline Bufavirus, and Feline Rotavirus

by Kaichuang Shi, Mengyi He, Feng Long, Junxian He, Yanwen Yin, Shuping Feng and Zongqiang Li

Microbiol. Res. 2024, 15(4), 2129-2145; https://doi.org/10.3390/microbiolres15040143 - 21 Oct 2024

Viewed by 966

Abstract

Feline kobuvirus (FeKoV), feline astrovirus (FeAstV), feline bufavirus (FeBuV), and feline rotavirus (FRV) are important pathogens for gastroenteritis, which is characterized by vomiting, diarrhea, and dehydration. Four pairs of primers and probes were designed to target the FeKoV VP1, FeAstV ORF2, FeBuV VP2, [...] Read more.

Feline kobuvirus (FeKoV), feline astrovirus (FeAstV), feline bufavirus (FeBuV), and feline rotavirus (FRV) are important pathogens for gastroenteritis, which is characterized by vomiting, diarrhea, and dehydration. Four pairs of primers and probes were designed to target the FeKoV VP1, FeAstV ORF2, FeBuV VP2, and FRV NSP4 genes, and a quadruplex real-time quantitative RT-PCR (RT-qPCR) assay capable of the simultaneous detection of four feline enteroviruses was developed after optimization of reaction conditions. The established quadruplex RT-qPCR assay showed high specificity, sensitivity, and reproducibility. The assay could detect and discriminate FeKoV, FeAstV, FeBuV, and FRV, but not other feline-related pathogens. The limits of detection (LODs) of FeKoV, FeAstV, FeBuV, and FRV were 109.761, 115.834, 125.481, and 113.875 copies/reaction, respectively. The intra- and inter-assay coefficients of variation (CV) were 0.15–1.61% and 0.15–1.59%, respectively. In all, 1869 clinical samples from Guangxi province in Southern China were tested using the developed assay, and the positivity rates of FeKoV, FeAstV, FeBuV, and FRV were 1.93%, 9.36%, 0.32%, and 0.75%, respectively. These samples were also tested using reference assays, and the coincidence rates of the results between the developed and reference methods were 99.63% (FeKoV), 98.72% (FeAstV), 100% (FeBuV), and 100% (FRV), respectively. The results indicated that the developed assay could provide a new detection method for these four viruses associated with feline gastroenteritis. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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8 pages, 1164 KiB

Open AccessArticle

Correlation between Anti-Toxoplasma gondii IgG Antibodies in Serum and Colostrum of Naturally Infected Sheep and Passive Immunization in Lambs

by Felipe Boniedj Ventura Alvares, Brendo Andrade Lima, Ana Maria Santos Lima, Samira Pereira Batista, Antônia Aniellen Raianne Moisés Aguiar, Larissa Claudino Ferreira, Welitânia Inácia Silva, Thais Ferreira Feitosa and Vinícius Longo Ribeiro Vilela

Microbiol. Res. 2024, 15(3), 1806-1813; https://doi.org/10.3390/microbiolres15030120 - 6 Sep 2024

Viewed by 889

Abstract

Toxoplasmosis, caused by Toxoplasma gondii, poses a significant threat to sheep flocks, affecting reproductive performance and meat quality, and leading to economic losses. This study aimed to evaluate the correlation between anti-T. gondii IgG antibodies in the serum and colostrum of [...] Read more.

Toxoplasmosis, caused by Toxoplasma gondii, poses a significant threat to sheep flocks, affecting reproductive performance and meat quality, and leading to economic losses. This study aimed to evaluate the correlation between anti-T. gondii IgG antibodies in the serum and colostrum of naturally infected ewes and to assess passive immunity in newborn lambs. Blood and colostrum samples were collected from 162 ewes and 182 lambs across 20 sheep farms in Paraíba, Brazil. Samples were tested for anti-T. gondii and anti-Neospora caninum IgG using indirect fluorescence antibody tests (IFATs), with titers ≥ 1:64 considered positive. Among the ewes, 45.1% tested positive for anti-T. gondii IgG in serum, with titers ranging from 1:64 to 1:16,384. The colostrum from 94.6% of the ewes also tested positive, although 74% had higher titers in their serum than in their colostrum. Concordance between serum and colostrum was high, with a kappa coefficient of 0.950. Lamb serum showed a perfect agreement with maternal colostrum (kappa = 0.962), demonstrating effective passive transfer of antibodies. This study confirms that colostrum is a reliable matrix for detecting anti-T. gondii antibodies and assessing passive immunity in lambs. The high concordance between serum, colostrum, and lamb titers suggests that IFATs on colostrum can be a practical tool for monitoring maternal antibody transfer, contributing to the better management of T. gondii infections in sheep flocks. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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14 pages, 1161 KiB

Open AccessArticle

Detection of Bacteria with Potential to Cause Hospital-Associated Infections in a Small-Species Veterinary Hospital in Mexico

by Diego Josimar Hernández-Silva, Ana Isabel Rivera-González, Laura Karina Avilés-Benitez, Mayra M. Becerra-Reyes, Carlos Rivera-Ballesteros, Rodrigo Morales-García, Larisa García-Ramírez, Orlando Federico Chávez-Moreno, Gabriela Aguilar-Tipacamu, José Guadalupe Gómez-Soto and Juan Mosqueda

Microbiol. Res. 2024, 15(3), 1758-1771; https://doi.org/10.3390/microbiolres15030117 - 31 Aug 2024

Viewed by 1807

Abstract

Hospital-Associated Infections (HAIs) are caused by microorganisms that are not present before patients are admitted to healthcare facilities, and usually have multidrug resistance profiles. There is ample information and active research in human medicine to create preventive and control measures, but there have [...] Read more.

Hospital-Associated Infections (HAIs) are caused by microorganisms that are not present before patients are admitted to healthcare facilities, and usually have multidrug resistance profiles. There is ample information and active research in human medicine to create preventive and control measures, but there have been fewer efforts in animal medicine, and studies in only a few countries have been examining how this problem presents in veterinary hospitals. In Mexico, there have been no studies on the presence of multidrug-resistant bacteria associated with HAIs in veterinary medicine. Therefore, the surfaces of inanimate objects and equipment in a university veterinary hospital for small species were sampled to search for bacteria with the potential to cause HAIs. After isolation, molecular identification and multidrug resistance tests were carried out. One bacterial strain was found to be resistant to carbapenems, third-generation cephalosporines, and penicillin/β-lactamase inhibitors. Additionally, other susceptible bacterial genera were identified as potential nosocomial pathogens in humans and animals. The presence of multidrug-resistant bacteria was confirmed. Further studies should be conducted to determine the isolate’s origin and its relationship with reported human clinical genotypes. This type of study highlights the importance of epidemiological surveillance and the need to not underestimate the potential risk posed by multidrug-resistant microorganisms. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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11 pages, 2074 KiB

Open AccessArticle

Temporal Trends in Antimicrobial Resistance of Klebsiella pneumoniae in Clinically Affected Canine and Feline Populations in Germany: A 2019–2021 Analysis

by Stefanie Katharina Frenzer, Leonie Feuer, Wolfgang Bäumer, Antina Lübke-Becker, Babette Klein and Roswitha Merle

Microbiol. Res. 2024, 15(3), 1634-1644; https://doi.org/10.3390/microbiolres15030108 - 22 Aug 2024

Viewed by 1282

Abstract

Klebsiella (K.) pneumoniae is a major pathogen in human and veterinary medicine, known for its high resistance rates. Comprehensive resistance data are essential to combat global antibiotic resistance. This study aims to (a) document the prevalence of resistant K. pneumoniae and [...] Read more.

Klebsiella (K.) pneumoniae is a major pathogen in human and veterinary medicine, known for its high resistance rates. Comprehensive resistance data are essential to combat global antibiotic resistance. This study aims to (a) document the prevalence of resistant K. pneumoniae and (b) assess the utility of routine laboratory data for passive monitoring. We analyzed a dataset of 175,171 samples from diseased dogs and cats in Germany collected between 2019 and 2021, identifying 1185 K. pneumoniae isolates with measurable minimum inhibitory concentration values. We evaluated resistance rates to a third-generation cephalosporin (cefovecin) (16.3%), chloramphenicol (16.1%), doxycycline (13.9%), enrofloxacin (8.9%), gentamicin (6.0%), nitrofurantoin (24.8%), and sulfamethoxazole-trimethoprim (15.0%). Notably, feline K. pneumoniae isolates from the urinary tract showed a high cefovecin resistance rate of 70.0%. Comparing our findings with third-generation cephalosporin-resistant human isolates from the Antimicrobial Resistance Surveillance database (ARS) maintained by the Robert Koch Institute revealed a lower resistance rate (7.7%). This study presents Germany’s most comprehensive dataset on K. pneumoniae resistance in companion animals over a three-year period. These findings can strengthen national resistance monitoring efforts and enhance data interpretation through substantial datasets. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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17 pages, 993 KiB

Open AccessArticle

New Insights into Molecular Characterization, Antimicrobial Resistance and Virulence Factors of Methicillin-Sensitive Coagulase-Positive Staphylococcus spp. from Dogs with Pyoderma and Otitis Externa

by Faten Ben Chehida, Wafa Tombari, Haythem Gharsa, Youssef Rabia, Sana Ferhi, Maha Jrad and Lilia Messadi

Microbiol. Res. 2024, 15(3), 1208-1224; https://doi.org/10.3390/microbiolres15030081 - 12 Jul 2024

Viewed by 1281

Abstract

The first Tunisian national molecular survey of coagulase-positive staphylococci (CoPS) isolated from dogs with pyoderma and otitis externa was conducted to evaluate the prevalence of CoPS and identify its phenotypic and genotypic diversities. A total of 99 out of the 195 samples collected [...] Read more.

The first Tunisian national molecular survey of coagulase-positive staphylococci (CoPS) isolated from dogs with pyoderma and otitis externa was conducted to evaluate the prevalence of CoPS and identify its phenotypic and genotypic diversities. A total of 99 out of the 195 samples collected from 39 sick dogs were identified across multiple sites as methicillin-susceptible CoPS belonging to the species S. pseudintermedius (64.4%), S. aureus (20.2%), S. coagulans (10.1%), and S. hyicus (5%). Fifteen sampled dogs carried more than one Staphylococcus species. Their antibiotic resistance and virulence factors were determined using conventional and molecular methods. Of the S. pseudintermedius isolates found, 17.4% were multidrug-resistant, whereas high rates of virulence genes were observed among the S. aureus isolates. On polystyrene surfaces, 75% of S. aureus isolates were biofilm producers, of which 15% were classified as strong producers. The capsular polysaccharide cap8 genotype was predominant among them. A MultiLocus Sequence Typing (MLST) analysis clustered the S.aureus isolates into five distinct sequence types (STs), with four assigned for the first time. Our findings highlight the spread of CoPS among diseased dogs and, especially, the emergence of S. hyicus, S. coagulans, multidrug-resistant S. pseudintermedius and S. aureus isolates with high genetic variability. The precise characterization of these strains, as well as their continuous monitoring, is necessary for the implementation of preventive strategies given the significant public health risk. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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16 pages, 4806 KiB

Open AccessArticle

A Quadruplex Reverse Transcription Quantitative Polymerase Chain Reaction for Detecting Canine Coronavirus, Canine Rotavirus, Canine Parvovirus, and Canine Distemper Virus

by Yandi Shi, Feng Long, Kaichuang Shi, Mengyi He, Yuwen Shi, Shuping Feng, Yanwen Yin, Xiankai Wei and Zongqiang Li

Microbiol. Res. 2024, 15(2), 746-761; https://doi.org/10.3390/microbiolres15020049 - 10 May 2024

Cited by 2 | Viewed by 1617

Abstract

Background: Canine coronavirus (CCoV), canine rotavirus (CRV), canine parvovirus (CPV), and canine distemper virus (CDV) cause gastroenteritis in dogs, and co-infections of these pathogens are common in China. In particular, CCoV and CRV are confirmed to have important zoonotic potential and cause public [...] Read more.

Background: Canine coronavirus (CCoV), canine rotavirus (CRV), canine parvovirus (CPV), and canine distemper virus (CDV) cause gastroenteritis in dogs, and co-infections of these pathogens are common in China. In particular, CCoV and CRV are confirmed to have important zoonotic potential and cause public health issues. It is difficult to diagnose these diseases based only on clinical manifestations and pathological damage. Methods: In this study, four pairs of specific primers and probes targeting the CCoV M, CRV VP7, CPV VP2, and CDV N genes were designed. The reaction conditions, including the primer and probe concentrations, annealing temperatures, and reaction cycles, were optimized for the development of a quadruplex RT-qPCR for the detection of CCoV, CRV, CPV, and CDV. The assay was used to test 1028 clinical samples to validate its application. Results: A quadruplex RT-qPCR was successfully established for the differential detection of CCoV, CRV, CPV, and CDV, with good specificity, high sensitivity, and excellent repeatability. The assay could specifically detect CCoV, CRV, CPV, and CDV without cross-reactivity with the other canine viruses tested. It showed high sensitivity with limits of detection (LOD) of 1.1 × 10² copies/reaction for all four plasmid constructs. It showed excellent repeatability, with 0.05–0.90% intra-assay variation and 0.02–0.94% inter-assay variation. The 1028 clinical samples were tested using the quadruplex RT-qPCR and a reported reference RT-qPCR. The positivity rates of CCoV, CRV, CPV, and CDV were 9.53%, 0.97%, 25.68%, and 5.06% using the developed assay, and 9.05%, 0.88%, 25.68%, and 4.86% using the reference assay, with agreements higher than 99.32%. Conclusion: The results indicated that a rapid and accurate quadruplex RT-qPCR was developed for the detection and differentiation of CCoV, CRV, CPV, and CDV. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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Review

Jump to: Research, Other

19 pages, 804 KiB

Open AccessReview

In Ovo Vaccination Technology: An Alternative Approach to Post-Hatch Vaccination in Modern Poultry Operations

by Wafaa A. Abd El-Ghany

Microbiol. Res. 2025, 16(1), 7; https://doi.org/10.3390/microbiolres16010007 - 30 Dec 2024

Viewed by 1696

Abstract

Poultry production systems are usually exposed to important infections that could be prevented by vaccination programs. Conventional methods of vaccination such as drinking water; spray, eye, or nose inoculation; and injection are usually given after hatching and have many disadvantages. Therefore, there is [...] Read more.

Poultry production systems are usually exposed to important infections that could be prevented by vaccination programs. Conventional methods of vaccination such as drinking water; spray, eye, or nose inoculation; and injection are usually given after hatching and have many disadvantages. Therefore, there is a great need for searching of alternative ways for vaccination process. In ovo vaccination technology is now regarded as an alternative approach to post-hatch vaccination in modern poultry operations. This technique is effective, fast, provides uniform vaccine dosing and delivery, is suitable for massive production, and reduces labor costs. Routine in ovo vaccination is applied during the late stage of embryonic development between days 17.5 and 19.25 of egg incubation. The best route of inoculation of the vaccine is in the amniotic fluid or in the embryo’s muscles, without causing any hatchability or chick quality losses. Accordingly, the inoculation site, the age of the embryos and breeders, presence of maternal antibodies, and the sanitation of equipment’s and the environment during the vaccination process affect the efficiency of the in ovo vaccination technique. In ovo vaccination technology is currently applied for vaccination against several economically important viral diseases such as Newcastle, infectious bursal disease, Marek’s disease, infectious laryngotracheitis, infectious bronchitis, avian influenza, and avian metapneumovirus. Moreover, vaccines used for prevention of mycoplasmosis and coccidiosis could be applied in ovo instead of in post-hatching application. It can be concluded that in ovo vaccination is a rapidly growing trend of vaccine technology, and it can replace post-hatching vaccination conventional methods. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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11 pages, 538 KiB

Open AccessReview

Alteration of the Intestinal Bacterial Community in Rainbow Trout (Oncorhynchus mykiss): The Role of Animal, Plant, and Microbial Diets

by Aleksandra S. Chervochkina, Nadezhda O. Pastukhova and Andrey S. Aksenov

Microbiol. Res. 2024, 15(4), 2199-2209; https://doi.org/10.3390/microbiolres15040147 - 26 Oct 2024

Viewed by 1457

Abstract

Intestinal bacterial community in rainbow trout (Oncorhynchus mykiss) is increasingly recognized as important for aquaculture and fish health. This review summarizes the current knowledge on how various feed components, including animal- and plant-derived ingredients, as well as other feed additives, influence [...] Read more.

Intestinal bacterial community in rainbow trout (Oncorhynchus mykiss) is increasingly recognized as important for aquaculture and fish health. This review summarizes the current knowledge on how various feed components, including animal- and plant-derived ingredients, as well as other feed additives, influence the gut microbiota of rainbow trout. Studies using 16S rRNA gene profiling and metagenomics demonstrate how dietary changes affect the composition, diversity, and functionality of bacterial communities. The findings suggest that there is no single optimal alternative ingredient for fish feeds, but emphasize that the ratio of natural components plays a more significant role in shaping the intestinal bacterial community of trout. This balance is crucial for maintaining diversity, functionality, and overall fish health, thereby promoting growth and disease resistance, while enhancing aquaculture efficiency. The use of popular animal protein derived from the larva of Hermetia illucens increases the amount of Pseudomonadota, but the chitin they contain can prevent the absorption of nutrients. Thus, the development of optimal feed formulas requires careful selection and balancing of various natural ingredients to sustain a healthy microbiota and overall fish well-being. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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Other

Jump to: Research, Review

14 pages, 4251 KiB

Open AccessBrief Report

Effect of Tilapia Parvovirus (TiPV) on Fish Health: An In Vitro Approach

by Vikash Kumar, Basanta Kumar Das, Anupam Adhikari, Kampan Bisai and Biswajit Mandal

Microbiol. Res. 2025, 16(3), 68; https://doi.org/10.3390/microbiolres16030068 - 17 Mar 2025

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Abstract

Tilapia Parvovirus (TiPV) is a rising pathogen responsible for high mortality in tilapia aquaculture. Understanding TiPV’s pathogenesis is crucial for developing effective management strategies. This study aimed to elucidate TiPV pathogenesis by evaluating its cytotoxic effects on Danio rerio gill (DRG) cell monolayers [...] Read more.

Tilapia Parvovirus (TiPV) is a rising pathogen responsible for high mortality in tilapia aquaculture. Understanding TiPV’s pathogenesis is crucial for developing effective management strategies. This study aimed to elucidate TiPV pathogenesis by evaluating its cytotoxic effects on Danio rerio gill (DRG) cell monolayers and its impact on host immune responses. PCR-confirmed TiPV-infected DRG cell monolayers were subjected to an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay at 24, 48, 72, and 96 h post-infection to assess cell viability and cytotoxicity. The MTT assay revealed a progressive decline in DRG cell viability over time, with viable cell percentages decreasing from 66.71% at 24 h to 31.28% at 96 h in TiPV-infected cultures, compared to consistently high viability in controls. Simultaneously, quantitative real-time PCR (qPCR) was used to assess the expression of key immune-related genes, including Interleukins (IL-1β, IL-8), Toll-like receptor 7 (TLR7), Major Histocompatibility Complex II (MHC-II), Tumor Necrosis Factor α (TNF-α), Nuclear Factor Kappa B (NF-κB), and Chemokine Receptors (CRs).qPCR analysis showed an upregulation of IL-8, IL-1β, TNF-α, and CRs, indicating an early inflammatory response. However, significant downregulation of TLR7, MHC-II, and NF-κB suggests TiPV’s ability to modulate host immune responses. The results highlight that TiPV induces significant cytotoxicity in DRG cells, leading to severe cellular damage. The virus also alters host immune responses by modulating the expression of key immune genes, which may contribute to its virulence and persistence. These findings enhance our understanding of TiPV pathogenesis and highlight the need for targeted research to develop effective control strategies for TiPV in aquaculture systems. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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8 pages, 973 KiB

Open AccessBrief Report

Germination and Culturability after UV Irradiation of Metarhizium anisopliae Native from Soils of Tropical Cattle Farms

by Miguel Ángel Alonso-Díaz, María de Lourdes Lozano-Velázquez, Iván Adrián García-Galicia and Agustín Fernández-Salas

Microbiol. Res. 2024, 15(3), 1326-1333; https://doi.org/10.3390/microbiolres15030089 - 25 Jul 2024

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Abstract

The use of entomopathogenic fungi (EF) is a promising alternative for the control of Rhipicephalus microplus, an important tick affecting cattle globally. This study aimed to evaluate the effect of ultraviolet irradiation (UV) exposure on the percentage of conidia germination and number [...] Read more.

The use of entomopathogenic fungi (EF) is a promising alternative for the control of Rhipicephalus microplus, an important tick affecting cattle globally. This study aimed to evaluate the effect of ultraviolet irradiation (UV) exposure on the percentage of conidia germination and number of colony-forming units of eight strains of Metarhizium anisopliae (MaV55, MaV35, MaV31, MaV25, MaV13, Ma08, MaV05, and MaV02). The UV (UV-A and UV-A+B) irradiation was carried out with an ultraviolet radiation emission lamp. The conidia of each strain were exposed to the UV irradiation treatments for 3 h. MaV25, MaV08, MaV05, MaV13, and MaV31 showed higher tolerance to UV-A radiation exposure, as assessed by conidia germination. UV-A+B radiation decreased the germination percentage of all the M. anisopliae strains. The eight evaluated strains showed good tolerance to UV-A radiation, as assessed by the development of colony-forming units (CFU). UV-A+B radiation did not significantly affect (p > 0.05) the count of the CFU of six of the M. anisopliae strains evaluated (MaV35, MaV13, MaV08, MaV05, MaV31, and MaV02). The novel findings of the UV-tolerant M. anisopliae strains may potentially improve the effectiveness of EF under environmental conditions. Integral research under real tropical conditions is advised to evaluate the effectiveness of the EF strains. Full article

(This article belongs to the Special Issue Veterinary Microbiology and Diagnostics)

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