scholarly journals Isolation of Yersinia pseudotuberculosis in bovine mastitis: A potential milk-borne hazard

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Andrea Lorusso ◽  
Luciana Addante ◽  
Loredana Capozzi ◽  
Angelica Bianco ◽  
Laura Del Sambro ◽  
...  

This paper describes the first confirmed case of a subclinical mastitis caused by Yersinia pseudotuberculosis in a dairy cow from Italy. Milk samples from an adult cow of the Bruna breed were analyzed accordingly to standard milk cultivation protocols. Bacteriological examinations allowed to isolate atypical Gram-negative rods identified as Y. pseudotuberculosis using biochemical tests. The isolate was subjected to Whole Genome Sequencing (WGS) and the species identification was confirmed using rMLST. Moreover, the virulence and antibacterial susceptibility of the isolate have been also determined. The most common virulence genes were screened through WGS, showing the presence of inv, ail, pil and HPI genes. No antibiotic resistance was found. Even though scarcely described as causal agent of subclinical mastitis, the detection of Y. pseudotubercolusosis suggests that this pathogen could be spread to humans through raw milk, representing a potential food safety hazard.

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Desiye Tesfaye Tegegne ◽  
Gezahegne Mamo ◽  
Hika Waktole ◽  
Yohannes Equar Messele

Abstract Purpose Staphylococcus aureus (S. aureus) is the most important pathogen involved in bovine mastitis in dairy production. S. aureus produces a spectrum of extracellular protein toxins and virulence factors which are thought to contribute to the pathogenicity of the organism. The aim of this work was to isolate and molecular characterize S. aureus associated with bovine subclinical mastitis in the central part of Ethiopia. Methods A total of 265 lactating dairy cows from various dairy farms in four different geographical locations were screened by the California mastitis test (CMT) for bovine subclinical mastitis. One hundred thirty CMT-positive milk samples were collected and transported to the laboratory. Different biochemical tests and polymerase chain reaction (PCR) were used for the identification of S. aureus isolates. Finally, PCR was performed for molecular detection of virulence genes. Results From a total of 265 lactating dairy cows screened, 49% (n = 130) were positive for bovine subclinical mastitis. One hundred thirty mastitic milk samples were subjected to bacterial culturing, and one hundred (76%) S. aureus isolates were identified based on phenotypic characters. Sixty-eight confirmed S. aureus isolates were obtained using PCR. The confirmed S. aureus isolates were tested for six virulence genes (tsst-1, hlb, eta, sea, clfA, and icaD) using PCR. Of the six virulence genes screened from all the isolates, only two (clfA and eta) were detected in the isolates. Out of 68 isolates, 25% and 22% were possessed the eta and clfA genes, respectively. Conclusion The presence of Staphylococcus aureus having virulence genes (eta and clfA) revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.


Author(s):  
S. H. M. Faruk Siddiki

Background: Mastitis is one of the most prevalent complex diseases of mammals with high economic impact in dairy industry worldwide. Most of the published inland reports on bovine mastitis are mainly based on sub-clinical mastitis and some extent to clinical types. Objectives: The main objectives of this study are (a) to compare the bacterial pathogens associated with sub-clinical, clinical and chronic mastitis, and (b) to detect the antibiotic sensitivity and resistance status of the isolated bacteria from different types of mastitis. Materials and Methods: A total of 539 quarter milk samples, collected from lactating cows of Rajshahi and Mymensingh districts were subjected to standard bacterial culture and biochemical tests during the period of 2010-2011. Antibiogram test was done on bacteria isolated from sub-clinical (n = 444), acute (n = 35) and chronic (n = 60) mastitis cases include Staphylococcus spp., Streptococcus spp., Bacillus spp. and E. coli in 78.54%, 80% and 71.67% milk samples as a single and 21.46%, 20% and 28.33% as mixed infection, respectively. Results: The Staphylococcus spp. was recorded as major pathogen for all the sub-clinical (42.15%), acute (45.71%) and chronic (41.67%) mastitis cases. The right hind quarters were found significantly (p < 0.05) more affected with sub-clinical, acute and chronic types of mastitis than other three quarters in cows. The highest sensitivity (up to 100%) was recorded with gentamicin, ciprofloxacin, oxytetracycline and enrofloxacin against all the tested four organisms isolated from sub-clinical, clinical and chronic mastitis cases. Antibiotic resistance was highly prevalent, especially streptomycin (70-100%), amoxicillin (30-100%) and ampicillin (0-100%) against the four isolated bacteria of three different types of mastitis. Conclusions: It may be concluded that there is a need to establish a nationwide plan for monitoring the resistance of antibiotics and ensure the cautious use of antibiotics in the veterinary medical practices. Keywords: Bovine mastitis, Clinical mastitis, Subclinical mastitis, Chronic mastitis, Mastitic bacterial pathogens and Antibiogram


2016 ◽  
Vol 84 (1) ◽  
pp. 80-88 ◽  
Author(s):  
Carla Margarida Duarte ◽  
Carla Carneiro ◽  
Susana Cardoso ◽  
Paulo Peixeiro Freitas ◽  
Ricardo Bexiga

Bovine mastitis is the most costly disease for dairy farmers, hence, control measures to prevent it are crucial for dairy farm sustainability. Staphylococcus aureus is considered a major mastitis pathogen because of its impact on milk quality and low cure rates. Prevention of S. aureus mastitis includes segregation of infected animals, whilst treatment of such animals should be performed for a longer time to improve cure rates. This makes identification of S. aureus infected quarters and animals of significant importance. The experiments reported in this research paper aimed to develop and validate a sensitive method for magnetic detection of S. aureus and of the Staphylococcus genus in raw milk samples. Mastitic milk samples were collected aseptically from 47 cows with subclinical mastitis, from 12 Portuguese dairy farms. Forty nine quarter milk samples were selected based on bacteriological results. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analysed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. The antibodies used in this work were a rabbit polyclonal IgG anti-S. aureus ScpA protein and a mouse monoclonal IgM anti-S. aureus ATCC 29740. This paper describes the methodology used for magnetic detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence above 100 cfu/ml, independently of antibody and targeted bacteria used in this work. Comparison with PCR results showed sensitivities of 57·1 and 79·3%, specificity values of 75 and 50%, and PPV values of 40 and 95·8% for magnetic identification of Staphylococci species with an anti-S. aureus antibody and an anti-Staphylococcus spp. antibody, respectively. Some constraints are described as well as the method's limitations in bacterial quantification. Sensitivities and specificities require to be improved, nevertheless, the methodology described may form the basis for a means of identifying S. aureus infected cows at the point of care.


2021 ◽  
Author(s):  
Desiye Tesfaye Teegegne ◽  
Gezahegne Mamo ◽  
Hika Waktole ◽  
Yohannes Equar Messele

Abstract Purpose: Staphylococcus aureus (S. aureus) is the most important pathogen involved in bovine mastitis in dairy production. S. aureus produces a spectrum of extracellular protein toxins and virulence factors which are thought to contribute to the pathogenicity of the organism. The aim of this work was to isolate and molecular characterize S. aureus associated with bovine subclinical mastitis in central part of Ethiopia.Methods: A total of 265 lactating dairy cows from various dairy farms in four different geographical locations were screened by California mastitis test (CMT) for bovine subclinical mastitis. One-hundred thirty CMT positive milk samples were collected and transported to laboratory. Different biochemical tests and polymerase chain reaction (PCR) were used for the identification of S. aureus isolates. Finally, PCR was performed for molecular detection of virulence genes. Results: From total of 265 lactating dairy cows screened, 49% (n=130) were positive for bovine subclinical mastitis. One-hundred thirty mastitic milk samples were subjected to bacterial culturing, one hundred (76%) S. aureus isolates were identified based on phenotypic characters. Sixty-eight confirmed S. aureus isolates were obtained using PCR. The confirmed S. aureus isolates were tested for six virulence genes (tsst-1, hlb, eta, sea, clfA and icaD) using PCR. Of the six virulence genes screened from all the isolates, only two (clfA and eta) were detected in the isolates. Out of 68 isolates, 25% and 22% were possessed the eta and clfA genes, respectively. Conclusion: Presence of Staphylococcus aureus having virulence genes (eta and clfA) revealed that mastitis is a major concern nowadays affecting animal health, milk quality, and yield. Further genomic study of these isolates will provide broad new insights on virulence.


2018 ◽  
Vol 11 (2) ◽  
Author(s):  
E Mahmmoud ◽  
G Shamoon

A total of 141 milk samples were tested belong to 27 cows infected with clinical mastitis and 114 cows were diagnosed with subclinical mastitis after detected their milk samples by California Mastitis and Whiteside tests, samples were collected from different areas of Mosul city. After the first isolation, the biochemical tests were carried out on all isolation. The samples showed 33 (23.40%) isolates of Coagulase-Negative Staphylococci (C-NS). S. chromogenes & S. epidermidis were predominant in clinical mastitis, while in the sub-clinical cases the S. haemolyticus was most frequently in isolation. The sensitivity test was carried out on isolated bacteria. The test results showed that there was absolute resistance to ampicillin and 90.9% for Penicillin-G, while the lowest resistance and highest sensitivity of Chloramphenicol was 27.27%, 57.57%, respectively, as well as, isolated give varying sensitivity and resistance to other antibiotics. The use of antibiotics at random and the non-completion of treatment the animal by the owner lead to produce a normal flora resistant to most common veterinary antibiotics used, which can become a pathogen when conditions are available, this shown by the results of the current study.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.


2017 ◽  
Vol 14 (2) ◽  
pp. 277-282 ◽  
Author(s):  
M. A. Islam ◽  
S. M. L. Kabir ◽  
M. T. Rahman

The study was intended for molecular detection of S. aureus isolated from raw cow’s milk. A total of 20 milk samples were collected from different upazila markets of Jamalpur, Tangail, Kishoreganj and Netrokona districts of Bangladesh. Milk samples were cultured onto various culture media for the isolation of bacteria. The isolated bacteria were identified by studying cultural properties on different selective media, biochemical tests, and finally by PCR. Out of 20 samples, 15 (75%) milk samples were found to be positive for S. aureus. S. aureus specific 16S rRNA gene was amplified from all isolates and identified as S. aureus. Antimicrobial sensitivity test was carried out to ascertain the susceptibility of the organism to various antibiotics. Its results showed that the S. aureus isolates were resistant to amoxicillin (100%), erythromycin (73.33%) and tetracycline (73.33%) but sensitive to azithromycin (93.33%), ciprofloxacin (93.33%), gentamicin (100%), norfloxacin (86.67%) and streptomycin (86.67%).


Author(s):  
C. Ghazaei

Mycoplasmas are an important and economically significant cause of mastitis in dairy cows in various parts of the world. The organisms are highly contagious, with the main reservoir of infection originating from cows with subclinical mastitis. In 1998 the 1st cases of bovine mastitis due to Mycoplasma bovis were diagnosed in Ardabil State, Iran. An investigation was carried out with the aim of establishing the extent of mycoplasma infections in dairy cows in Ardabil State. Milk samples obtained from 80 cows with clinical mastitis were cultured in the laboratory for the presence of mycoplasmas. Similarly, 48 bulk-tank milk samples were examined for the presence of mycoplasmas. A modified Hayflick broth was used to isolate the mycoplasmas and an immunoperoxidase test used for the species identification of the isolates. Mycoplasma bovis was isolated from 39 (48.75 %) of the clinical mastitis samples and from 48 of the bulk-tank milk samples tested. This indicated that mycoplasma udder infections were more prevalent in dairy cows in Ardabil State than previously thought.


2022 ◽  
Vol 43 (2) ◽  
pp. 901-910
Author(s):  
Lilian Bernardina Ferreira ◽  
◽  
Larissa de Freitas Santiago Israel ◽  
Renata Fernandes Rabello ◽  
Guilherme Nunes de Souza ◽  
...  

Staphylococcus bacteria are often associated with subclinical bovine mastitis. This study aimed to identify multiresistant Staphylococcus spp. associated with subclinical mastitis and the associated risk factors. Twenty-three dairy farms with a history of decrease in milk production, located in the lower Acre region, Brazil, were selected. An epidemiological questionnaire was provided in all farms. All animals were examined using the California Mastitis Test (CMT) and their milk samples were collected for bacterial culture. After isolation and identification, the disk diffusion antimicrobial susceptibility test was performed against nine classes of antimicrobials. Of the 339 cows examined using the CMT, 108 had mastitis. A total of 229 milk samples were collected from individual teats. MALDI-TOF MS found isolates belonging to eight species of Staphylococcus, in 101 of these samples. S. chromogenes (58.4%) demonstrated strongest resistance to the nine classes of antimicrobial active principles. Nineteen isolates with multidrug resistance phenotypic profile were identified. This phenotypic expression indicates wide circulation of resistant genes in this species. The presence of multidrug resistance in Staphylococcus spp. in this study was correlated with lack of water for cleaning the corral, which is a preventive factor, minimizing the transmission and persistence of pathogens in the farms.


1988 ◽  
Vol 51 (11) ◽  
pp. 840-841 ◽  
Author(s):  
MICHAEL B. LIEWEN ◽  
MARK W. PLAUTZ

Raw milk samples were obtained from bulk storage tanks of individual dairy farms in eastern Nebraska during February and July of 1986. One hundred different farms were tested during each period. One-tenth ml of each sample was plated directly onto McBride's Listeria Agar (MLA) and 30 ml was subjected to a four-week cold enrichment procedure. Suspect colonies from MLA were subjected to biochemical tests to confirm identity. Nine percent of all raw milk samples examined were determined to be positive for Listeria species after the cold enrichment procedure. Four percent contained L. monocytogenes and five percent contained L. innocua. Six percent and two percent of samples were found to contain L. monocytogenes in February and July respectively.


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