&lt;em&gt;Staphylococcus aureus &lt;/em&gt;Isolates From Bovine Mastitis in Eight Countries: Genotypes, Detection of Genes Encoding Different Toxins and Other Virulence Genes

Monistero, Valentina; Graber, H.U.; Pollera, C.; Cremonesi, Paola; Castiglioni, Bianca; Bottini, Enriqueta; Ceballos-Márquez, Alejandro; Lasso-Rojas, Laura; Kroemker, Volker; Wente, Nicole; Petzer, Inge-Marié; Santisteban, Carlos; Runyan, Jeff; Santos, Marcos Veiga dos; Piccinini, R.; Bronzo, V.; Abbassi, Mohamed Salah; Said, Myriam Ben; Moroni, P.

doi:10.20944/preprints201804.0325.v1

Cited by 17 publications

(1 citation statement)

References 11 publications

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“…Future studies need to be conducted to determine antibiotic resistance genes present in S. aureus isolated from dairy cattle in South Africa, as new S. aureus strains have been identified (Monistero et al 2018). In addition, the determination of biofilm expression of these isolates should be checked for seasonal and regional patterns.…”

Section: Discussionmentioning

confidence: 99%

Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds

Karzis

Petzer

Donkin

et al. 2019

Onderstepoort Journal of Veterinary Research

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South Africa is a large country of approximately 1.22 million km 2 , made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus , of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.

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Section: Discussionmentioning

confidence: 99%

Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds

Karzis

Petzer

Donkin

et al. 2019

Onderstepoort Journal of Veterinary Research

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Characterization of Virulence Factors in Enterotoxin-Producing Staphylococcus aureus from Bulk Tank Milk

Jung

Lee

2022

Animals

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Staphylococcus aureus, a persistent mastitis-causing pathogen, produces various virulence factors, including enterotoxins. This study analyzed the genetic characteristics of bovine-mastitis-related virulence factors to evaluate the potential pathogenesis of S. aureus isolated from bulk tank milk. Among 93 S. aureus isolates from 396 dairy farms operated by 3 dairy companies in Korea, 40 (43.0%) isolates carried one or more enterotoxin genes. Moreover, S. aureus carrying enterotoxin genes showed a higher prevalence in all virulence genes tested in this study except for pvl and lukM, which were not detected in any isolate, than in the isolates without enterotoxin genes. In particular, the prevalence of six genes (hla, hlb, lukED, fnbA, clfA, and clfB) was significantly higher in S. aureus carrying the enterotoxin genes than in the isolates without the enterotoxin genes (p < 0.05). The most common multilocus sequence type of enterotoxin-producing isolates was ST188, and all isolates of ST188 harbored the see gene. S. aureus isolated from bulk tank milk, not from mastitis, had a high prevalence of virulence factors, posing a public health threat. Moreover, a high presence of enterotoxins in bulk tank milk is probably because of poor hygiene; therefore, it is important to develop strong monitoring and sanitation programs for dairy factories.

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Dairy Cows’ Udder Pathogens and Occurrence of Virulence Factors in Staphylococci

Zigo

Farkašová

Výrostková

et al. 2022

Animals

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This study investigated 960 Slovak and Czech spotted cattle from four different conventional (non-organic) dairy herds located in Eastern Slovakia and Czechia during early lactation (14–100 days after calving). Dairy cows were examined clinically; milk from fore-stripping of each udder quarter was subjected to sensory examination and assessed by the California mastitis test (CMT), and laboratory analyses of bacterial pathogens in milk, including virulence factors, were conducted. Positive CMT scores (1–3) for one or more quarters were detected in 271 (28.2%) of the examined animals. Out of 230 infected milk samples, representing 24.0% of all dairy cows, staphylococci (59.1% of positive findings) were the most commonly isolated organisms, followed by E. coli (11.3%), streptococci Str. uberis (9.1%) and Str. agalactiae (3.4%), and enterococci (6.1%). From 136 isolates of S. aureus (38 isolates) and non-aureus staphylococci (NAS; 98 isolates), virulence factors and their resistance to 14 antimicrobials were detected using the disk diffusion method, with PCR detection of the methicillin resistance gene, mecA. An increased incidence of clinical and chronic forms of mastitis has been reported in mastitic cows in which staphylococci, especially S. aureus and NAS (S. chromogenes, S. warneri, and S. xylosus), have been detected and compared to other isolated udder pathogens. From those species, S. aureus and isolates of NAS mentioned above showed multiple virulence factors that are more likely to hydrolyze DNA, hemolysis, produce gelatinase and biofilm, and have multi-drug resistance as compared to other less virulent staphylococci. Generally, the isolated staphylococci showed 77.2% resistance to one or more antimicrobials, in particular to aminoglycosides, β-lactams, macrolides, or cephalosporins. Isolates that showed the ability to form a biofilm were more resistant to more than one antimicrobial than isolates without biofilm production. Multi-drug resistance to three or more antimicrobial classes was recorded in 16 isolates (11.7%), and the presence of the mecA gene was also confirmed in two isolates of S. aureus and two species of NAS.

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<em>Staphylococcus aureus </em>Isolates From Bovine Mastitis in Eight Countries: Genotypes, Detection of Genes Encoding Different Toxins and Other Virulence Genes

Cited by 17 publications

References 11 publications

Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds

Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds

Characterization of Virulence Factors in Enterotoxin-Producing Staphylococcus aureus from Bulk Tank Milk

Dairy Cows’ Udder Pathogens and Occurrence of Virulence Factors in Staphylococci

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