Karzis Joanne, Petzer Inge-Marie, Donkin Edward F, Naidoo Vinny, Etter Eric M C
Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria.
Onderstepoort J Vet Res. 2019 Jul 10;86(1):e1-e9. doi: 10.4102/ojvr.v86i1.1674.
South Africa is a large country of approximately 1.22 million km2, 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.
南非是一个幅员辽阔的国家，面积约122万平方公里，由九个省份组成，有三个气候带。该国的农业主要由地区差异决定。从奶牛的牛奶样本中分离出的不同微生物中，金黄色葡萄球菌对维持乳房健康和生产供人类食用的健康乳制品构成挑战。因此，抗生素耐药菌是一种潜在的健康危害。本研究的目的是调查金黄色葡萄球菌抗生素耐药性的季节性和地区关系，而这方面了解甚少。本研究旨在评估一组3410株金黄色葡萄球菌分离株的数据集，这些分离株取自体细胞计数>400000个细胞/毫升的商业奶牛群的牛奶样本。使用Kirby Bauer方法对这些分离株进行氨苄西林、氯唑西林、青霉素G、克林霉素、氧四环素、头孢氨苄、头孢呋辛和泰乐菌素的抗菌药敏试验。这些样本来自830个奶牛场，而南非估计有2000个商业奶牛场。除头孢菌素外，所有测试的抗生素在大多数省份的预测耐药率均高于50%，这令人担忧。在夸祖鲁-纳塔尔省春季，对大多数测试抗生素类别的耐药率最低。在豪登省冬季，头孢菌素的细菌耐药率最低。金黄色葡萄球菌对这八种抗生素的耐药模式在不同季节和省份有所不同，这可能是由于不同的天气条件以及抗生素的作用和光谱所致。
