Research

12 pages, 2096 KiB

Open AccessArticle

Optimization of RT-QuIC Assay Duration for Screening Chronic Wasting Disease in White-Tailed Deer

by Gokhan Yilmaz, Tamara Morrill, William Pilot, Cian Ward, Gordon Mitchell, Andrei Soutyrine, Hanhong Dan, Min Lin and Jiewen Guan

Vet. Sci. 2024, 11(2), 60; https://doi.org/10.3390/vetsci11020060 - 01 Feb 2024

Viewed by 1351

Abstract

Real-time quaking-induced conversion (RT-QuIC) assays have become a common tool to detect chronic wasting disease (CWD) and are very sensitive provided the assay duration is sufficient. However, a prolonged assay duration may lead to non-specific signal amplification. The wide range of pre-defined assay [...] Read more.

Real-time quaking-induced conversion (RT-QuIC) assays have become a common tool to detect chronic wasting disease (CWD) and are very sensitive provided the assay duration is sufficient. However, a prolonged assay duration may lead to non-specific signal amplification. The wide range of pre-defined assay durations in current RT-QuIC applications presents a need for methods to optimize the RT-QuIC assay. In this study, receiver operating characteristic (ROC) analysis was applied to optimize the assay duration for CWD screening in obex and retropharyngeal lymph node (RLN) tissue specimens. Two different fluorescence thresholds were used: a fixed threshold based on background fluorescence (T_stdev) and a max-point ratio (maximum/background fluorescence) threshold (T_MPR) to determine CWD positivity. The optimal assay duration was 33 h for obex and 30 h for RLN based on T_stdev, and 29 h for obex and 32 h for RLN based on T_MPR. The optimized assay durations were then evaluated for screening CWD in white-tailed deer from an affected farm. At a replicate level, using the optimized assay durations with T_Stdev and T_MPR, the level of agreement with enzyme-linked immunosorbent assay (ELISA) was significantly higher (p < 0.05) than that when using a 40 h assay duration. These findings demonstrate that the optimization of assay duration via a ROC analysis can improve RT-QuIC assays for screening CWD in white-tailed deer. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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9 pages, 1847 KiB

Open AccessCommunication

The Microbiota Architecture of the Chinchilla Gastrointestinal Tract

by Yuhong Wu, Bo Liu, Xinyi Ma, Luo Yang, Xinyi Lu, Wei Wang and Jing Li

Vet. Sci. 2024, 11(2), 58; https://doi.org/10.3390/vetsci11020058 - 28 Jan 2024

Viewed by 1419

Abstract

The gastrointestinal microbiota develop alongside the host and play a vital role in the health of cecal fermenters such as chinchillas. However, little is known about the microbiota architecture in healthy chinchillas. Illumine-based 16S rRNA gene amplicon sequencing was used to investigate the [...] Read more.

The gastrointestinal microbiota develop alongside the host and play a vital role in the health of cecal fermenters such as chinchillas. However, little is known about the microbiota architecture in healthy chinchillas. Illumine-based 16S rRNA gene amplicon sequencing was used to investigate the microbiota present in six different gastrointestinal tract regions of three healthy adult chinchillas. The findings revealed significantly more abundant microbiota in the large intestine compared with the proximal segments. In addition, the cecum exhibited better evenness compared to the colon. The core microbiota are Firmicutes, Bacteroidota, Actinobacteriota, and Proteobacteria at the phylum level. The signature microbiota of each segment were identified. The cecum had 10 signature microbiota, which had the widest coverage and overlapped with that of the cecum. The stomach had five signature microbiota, exhibiting the second widest coverage and overlapping with the duodenum. No signature microbiota were detected in the jejunum and ileum. While similarities exist with the microbiota of other cecal fermenters, chinchillas exhibit distinct microbiota closely related to their unique digestive mechanisms. This study is a preliminary study of the gastrointestinal microbiota architecture and distribution in healthy chinchillas. Further study is needed in order to better understand the effect of gastrointestinal microbiota on the health of the chinchilla. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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14 pages, 268 KiB

Open AccessArticle

Development and Validation of PCR Diagnostic Assays for Detection of Avibacterium paragallinarum and Ornithobacterium rhinotracheale

by Ekaterina Krylova, Alexandra Bogomazova, Nataliya Kirsanova, Anastasiya Putintseva, Natalia Gorbacheva, Olga Prasolova, Irina Soltynskaya and Olga Ivanova

Vet. Sci. 2024, 11(1), 7; https://doi.org/10.3390/vetsci11010007 - 22 Dec 2023

Viewed by 1364

Abstract

PCR is the most effective method for detecting difficult-to-cultivate pathogens and pathogens that are part of mixed infections in animals, such as Ornithobacterium rhinotracheale, which causes bird ornithobacteriosis, or Avibacterium paragallinarum, which causes infectious coryza. In this work, we developed and [...] Read more.

PCR is the most effective method for detecting difficult-to-cultivate pathogens and pathogens that are part of mixed infections in animals, such as Ornithobacterium rhinotracheale, which causes bird ornithobacteriosis, or Avibacterium paragallinarum, which causes infectious coryza. In this work, we developed and validated two efficient and sensitive diagnostic assays for the rapid and accurate detection of A. paragallinarum and O. rhinotracheale DNA in bacterial isolates and clinical samples using real-time PCR with TaqMan-like probes. When designing the PCR assays, we performed in silico analysis, optimized DNA isolation methods and PCR conditions, and assessed the analytical and diagnostic performance of PCR. We designed primers and probes that have no mismatches with published whole-genome sequences of bacteria. The optimization of conditions showed that the PCR assays are sufficiently robust to changes in temperature and oligonucleotide concentration. The validation showed that the developed assays have high analytical and diagnostic sensitivity and specificity. These assays are expected to improve the differential diagnosis of respiratory diseases in chickens and turkeys. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

12 pages, 1196 KiB

Open AccessArticle

Microbiota Characterization of the Cow Mammary Gland Microenvironment and Its Association with Somatic Cell Count

by Jing Liu, Huan Liu, Guangjie Cao, Yifang Cui, Huanhuan Wang, Xiaojie Chen, Fei Xu and Xiubo Li

Vet. Sci. 2023, 10(12), 699; https://doi.org/10.3390/vetsci10120699 - 11 Dec 2023

Viewed by 1434

Abstract

Subclinical mastitis is a common disease that threatens the welfare and health of dairy cows and causes huge economic losses. Somatic cell count (SCC) is the most suitable indirect index used to evaluate the degree of mastitis. To explore the relationship between SCC, [...] Read more.

Subclinical mastitis is a common disease that threatens the welfare and health of dairy cows and causes huge economic losses. Somatic cell count (SCC) is the most suitable indirect index used to evaluate the degree of mastitis. To explore the relationship between SCC, diversity in the microbiome, and subclinical mastitis, we performed next-generation sequencing of the 16S rRNA gene of cow’s milk with different SCC ranges. The data obtained showed that the microbiota was rich and coordinated with SCC below 2 × 10⁵. SCC above 2 × 10⁵ showed a decrease in the diversity of microbial genera. When SCC was below 2 × 10⁵, the phylum Actinobacteriota accounted for the most. When SCC was between 2 × 10⁵ and 5 × 10⁵, Firmicutes accounted for the most, and when SCC exceeded 5 × 10⁵, Firmicutes and Proteobacteria accounted for the most. Pathogenic genera such as Streptococcus spp. were absent, while SCC above 2 × 10⁵ showed a decrease in the diversity of microbial genera. SCC was positively correlated with the percentage of Romboutsia, Turicibacter, and Paeniclostridium and negatively correlated with the percentage of Staphylococcus, Psychrobacter, Aerococcus, and Streptococcus. Romboutsia decreased 6.19 times after the SCC exceeded 2 × 10⁵; the SCC increased exponentially from 2 × 10⁵ to 5 × 10⁵ and above 1 × 10⁶ in Psychrobacter. Analysis of the microbiota of the different SCC ranges suggests that the development of mastitis may not only be a primary infection but may also be the result of dysbiosis in the mammary gland. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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15 pages, 1903 KiB

Open AccessArticle

Isolation, Identification and Drug Resistance Rates of Bacteria from Pigs in Zhejiang and Surrounding Areas during 2019–2021

by Xiangfei Xu, Junxing Li, Pan Huang, Xuemei Cui, Xuefeng Li, Jiaying Sun, Yee Huang, Quanan Ji, Qiang Wei, Guolian Bao and Yan Liu

Vet. Sci. 2023, 10(8), 502; https://doi.org/10.3390/vetsci10080502 - 03 Aug 2023

Cited by 1 | Viewed by 2136

Abstract

This study aimed to determine the prevalence of bacterial diseases in pig farms in various regions of Zhejiang Province and surrounding areas. A total of 526 samples were collected from 85 pig farms in Zhejiang Province and surrounding areas. In this study, samples [...] Read more.

This study aimed to determine the prevalence of bacterial diseases in pig farms in various regions of Zhejiang Province and surrounding areas. A total of 526 samples were collected from 85 pig farms in Zhejiang Province and surrounding areas. In this study, samples were analyzed using bacterial isolation and purification, Gram staining, PCR amplification, and antimicrobial susceptibility testing. A total of 36 Pasteurella multocida (Pm) isolates were detected, with an isolation rate of 6.84%; 37 Bordetella bronchiseptica (Bb) isolates were detected, with an isolation rate of 7.03%; 60 Glasserella parasuis (G. parasuis) isolates were detected, with an isolation rate of 11.41%; 170 Escherichia coli (E. coli) isolates were detected, with an isolation rate of 32.32%; 67 Streptococcus suis (SS) isolates were detected, with an isolation rate of 12.74%; 44 Actinobacillus pleuropneumoniae (APP) isolates were detected, with an isolation rate of 8.37%; and 7 Salmonella enteritis (SE) isolates were detected, with an isolation rate of 1.33%. Antimicrobial drug susceptibility testing against 21 types of antibiotics was carried out on the isolated strains, and the results showed that 228 strains had varying degrees of resistance to 21 antibiotics, including Pm, Bb, E. coli, and APP, with the highest resistance to lincomycin, at 100%. Pm and APP were the most sensitive to cephalothin, with resistance rates of 0. In terms of strains, Pm had the highest overall sensitivity to 21 antibiotics, and E. coli had the highest resistance. In short, bacterial diseases in Zhejiang and the surrounding areas were harmful, and the drug resistance situation was severe. This study provides scientific guidance for the clinical treatment of bacterial diseases. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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10 pages, 2296 KiB

Open AccessArticle

Monitoring of Paenibacillus larvae in Lower Austria through DNA-Based Detection without De-Sporulation: 2018 to 2022

by Elfriede Wilhelm, Irina Korschineck, Michael Sigmund, Peter Paulsen, Friederike Hilbert and Wigbert Rossmanith

Vet. Sci. 2023, 10(3), 213; https://doi.org/10.3390/vetsci10030213 - 10 Mar 2023

Viewed by 1375

Abstract

American foulbrood is caused by the spore-forming Paenibacillus larvae. Although the disease effects honey bee larvae, it threatens the entire colony. Clinical signs of the disease are seen at a very late stage of the disease and bee colonies are often beyond [...] Read more.

American foulbrood is caused by the spore-forming Paenibacillus larvae. Although the disease effects honey bee larvae, it threatens the entire colony. Clinical signs of the disease are seen at a very late stage of the disease and bee colonies are often beyond saving. Therefore, through active monitoring based on screening, an infection can be detected early and bee colonies can be protected with hygiene measures. As a result, the pressure to spread in an area remains low. The cultural and molecular biological detection of P. larvae is usually preceded by spore germination before detection. In this study, we compared the results of two methods, the culture detection and RT-PCR detection of DNA directly isolated from spores. Samples of honey and cells with honey surrounding the brood were used in a five-year voluntary monitoring program in a western part of Lower Austria. DNA-extraction from spores to speed up detection involved one chemical and two enzymatic steps before mechanical bashing-beat separation and additional lysis. The results are comparable to culture-based methods, but with a large time advantage. Within the voluntary monitoring program, the proportion of bee colonies without the detection of P. larvae was high (2018: 91.9%, 2019: 72.09%, 2020: 74.6%, 2021: 81.35%, 2022: 84.5%), and in most P. larvae-positive bee colonies, only a very low spore content was detected. Nevertheless, two bee colonies in one apiary with clinical signs of disease had to be eradicated. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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8 pages, 8788 KiB

Open AccessCommunication

Virome Profiling of an Amur leopard cat Reveals Multiple Anelloviruses and a Bocaparvovirus

by Yang Liu, Lanshun Sun, Zhongzhong Tu, Sheng Sun, Yue Sun, Le Yi, Changchun Tu and Biao He

Vet. Sci. 2022, 9(11), 640; https://doi.org/10.3390/vetsci9110640 - 17 Nov 2022

Cited by 4 | Viewed by 1398

Abstract

As a small top predator, Amur leopard cat (Prionailurus bengalensis euptilurus) is widely distributed in northeast Asia and plays an important role in the control of small rodent populations and in the maintenance of ecological equilibrium. However, the viruses harbored by [...] Read more.

As a small top predator, Amur leopard cat (Prionailurus bengalensis euptilurus) is widely distributed in northeast Asia and plays an important role in the control of small rodent populations and in the maintenance of ecological equilibrium. However, the viruses harbored by this creature have been rarely investigated. Here, we report the DNA and RNA eukaryotic virome profiling of an injured Amur leopard cat followed by PCR validation, which revealed diverse anelloviruses in multiple organs and a bocaparvovirus in the lymph, but no RNA viruses. These anelloviruses have diverse genomic structures and are classified into four phylogroups with viruses of various felines, while the bocaparvovirus is extremely similar to those recovered from diarrheal domestic cats, illustrating the transmission of the virus between domestic animals and wildlife. These data provide the first insight into the genetic diversity of Amur leopard cat viruses, highlighting the need for further investigation of wild animals. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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10 pages, 2571 KiB

Open AccessArticle

High Concentration of FBS Can Save mTOR Down-Regulation Caused by Mycoplasmas bovis Infection

by Xiaochun Wu, Jinrui Ma, Shangdong Jia, Xudong Zhang, Xinlan Zhang, Zhen An, Yanquan Wei, Xiaoyong Xing, Fengqin Wen, Yuan Gao and Shijun Bao

Vet. Sci. 2022, 9(11), 630; https://doi.org/10.3390/vetsci9110630 - 11 Nov 2022

Viewed by 1416

Abstract

Mycoplasmas bovis (M. bovis) is an important pathogen that causes a variety of diseases, such as bovine respiratory diseases and causes significant losses to the national cattle industry every year, seriously affecting the development of the cattle industry worldwide. The pathogenic [...] Read more.

Mycoplasmas bovis (M. bovis) is an important pathogen that causes a variety of diseases, such as bovine respiratory diseases and causes significant losses to the national cattle industry every year, seriously affecting the development of the cattle industry worldwide. The pathogenic mechanism of M. bovis infection is still unknown, which leads to the lack of timely diagnosis and treatment. In this study, embryonic bovine lung (EBL) cells, infected with M. bovis were collected for gene profiling and detection of marker genes in the mTOR signaling pathway. The result showed that M. bovis infection significantly inhibits EBL growth in a dose-dependent manner. The transcription profiling data uncovered that M. bovis infection repressed a series of gene expressions in EBL cells, which are mainly related to metabolic process and immune response. Notably, many marker genes in the PI3K-Akt-mTOR pathway showed down-regulation after M. bovis infection. Further evidence showed that M. bovis infection inhibits expression of mTOR signaling pathway marker genes in EBL cells, which are time dependent. To further understand the M. bovis-induced inhibitory effect of mTOR signaling pathway, this study employed FBS as a supplement for exogenous nutrients and found that addition of a high concentration of FBS can rescue M. bovis-induced cell damage. In addition, a high concentration of FBS can rescue down-regulated mTOR signaling, including increasing transcriptional expression and protein phosphorylation level of mTOR pathway marker genes. This study demonstrated that M. bovis infection leads to inhibition of the nutrient metabolic pathway mTOR in a time-dependent manner, which would be helpful to further understand M. bovis infection mechanism and develop a new efficient anti-mycoplasma strategy targeting mTOR signaling. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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9 pages, 1536 KiB

Open AccessCommunication

Antibiotic Resistance and Species Profile of Enterococcus Species in Dogs with Chronic Otitis Externa

by Jun Kwon, Hyoung Joon Ko, Myoung Hwan Yang, Chul Park and Se Chang Park

Vet. Sci. 2022, 9(11), 592; https://doi.org/10.3390/vetsci9110592 - 27 Oct 2022

Cited by 5 | Viewed by 2711

Abstract

Otitis externa, a common disease in dogs, has different etiologies. Enterococcus is a Gram-positive bacterium that frequently causes opportunistic ear infections. Here, we determined the distribution of Enterococcus in canine otitis externa via time-of-flight mass spectrometry and biochemical tests and evaluated their resistance [...] Read more.

Otitis externa, a common disease in dogs, has different etiologies. Enterococcus is a Gram-positive bacterium that frequently causes opportunistic ear infections. Here, we determined the distribution of Enterococcus in canine otitis externa via time-of-flight mass spectrometry and biochemical tests and evaluated their resistance patterns to 10 commonly used antibiotics. Among the 197 Enterococcus isolates, E. faecalis (48.7%; 96/197) was the most common, followed by E. faecium (21.3%; 42/197), E. casseliflavus (11.7%; 23/197), E. hirae (10.7%; 21/197), E. avium (3.6%; 7/197), E. gallinarum (2.5%; 5/197), E. canintestini (1.0%; 2/197), and E. durans (0.5%; 1/197). All isolates were tested for antibiotic resistance using the Kirby–Bauer disc diffusion method. Enterococcus faecalis strains were highly resistant to erythromycin (45.8%) and rifampin (34.3%) but were generally susceptible to penicillin class antibiotics. In contrast, E. faecium isolates were highly resistant to penicillin class antibiotics (ampicillin, 61.9%; penicillin, 71.4%). Most importantly, E. faecium demonstrated high resistance to most of the antibiotics used in this study. Multidrug resistance was found in 28.4% of the isolates (56/197). This study shows prevalence and antibiotics resistance profiles of Enterococcus species in canine chronic otitis externa. The results can contribute to establish therapeutic strategies of Enterococcus infections and be used as a comparable index of antibiotic resistance of Enterococcus in the future. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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16 pages, 4512 KiB

Open AccessArticle

Microbiological Characteristics and Pathogenesis of Klebsiella pneumoniae Isolated from Hainan Black Goat

by Meirong He, Haoyang Li, Zhenxing Zhang, Junming Jiang, Hong Li, Weijie Yang, Yiwen Cheng, Hongyan Gao, Qiaoling Chen, Li Du, Si Chen, Churiga Man and Fengyang Wang

Vet. Sci. 2022, 9(9), 471; https://doi.org/10.3390/vetsci9090471 - 31 Aug 2022

Cited by 2 | Viewed by 4110

Abstract

K. pneumoniae is an opportunistic pathogen that leads to widespread infection in humans and animals, seriously threatening human health and animal husbandry development. In our research, we investigated the biological characteristics of the isolate by using a 16S rRNA gene sequencing, biochemical [...] Read more.

K. pneumoniae is an opportunistic pathogen that leads to widespread infection in humans and animals, seriously threatening human health and animal husbandry development. In our research, we investigated the biological characteristics of the isolate by using a 16S rRNA gene sequencing, biochemical assay, and drug sensitivity test. Moreover, the pathogenicity study, including the bacteria load determination, the histopathology examination, and the RNA sequencing was carried out to explore whether the isolate could cause lung injury in mice through intraperitoneal injection. The results indicated that the isolate was identified as K. pneumoniae and named as KPHN001. The drug susceptibility test showed that KPHN001 was only sensitive to polymyxin B and furazolidone, and was resistant to other 28 antibiotics. In the bacteria load determination, the highest bacterial load of the organs was found in the spleen, and abundant bacterial colonization was also found in the lung. The histopathology showed the mainly acute inflammations in the lung were due to congestion, edema, and exudation. RNA-seq analysis revealed that the differentially expressed genes (DEGs) of inflammatory cytokines and chemokines were expressed massively in mice. In the present research, the biological characteristics and pathogenesis of clinically isolated K. pneumoniae were systematically studied, revealing the pathogenic mechanism of K. pneumoniae to animals, and providing a theoretical basis for the following prevention, control, and diagnosis research. Full article

(This article belongs to the Special Issue Advances in Veterinary Clinical Microbiology)

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