Investigation of the antibiotic resistance and biofilm formation of Staphylococcus aureus strains isolated from gangrenous mastitis of ewes

In this study,Staphylococcus aureusstrains (n = 110) isolated from seven ewe flocks in Sanliurfa, Turkey were screened for antibiotic resistance and biofilmforming ability as well as for genes associated with antibiotic resistance and biofilm-forming ability. All isolates were found to be susceptible to oxacillin, gentamicin, clindamycin, cefoxitin, tetracycline, vancomycin, amoxicillin-clavulanic acid, ciprofloxacin and sulphamethoxazole-trimethoprim. The percent proportions of strains resistant to penicillin G, ampicillin and erythromycin were 27.2% (n = 30), 25.4% (n = 28) and 6.3% (n = 7), respectively. Regarding the antibiotic resistance genes, 32 (29%) isolates carried theblaZ and 8 (7.2%) theermC gene. Other resistance genes were not detected in the isolates. All isolates showed biofilm-forming ability on Congo red agar (CRA), while 108 (98.18%) and 101 (91.81%) of them were identified as biofilm producers by the use of standard tube (ST) and microplate (MP) methods, respectively. All isolates carried theicaA andicaD genes but none of them harboured thebapgene. The results demonstrated thatS. aureusisolates from gangrenous mastitis were mainly resistant to penicillins (which are susceptible to the staphylococcal beta-lactamase enzyme), and less frequently to erythromycin. Furthermore, all of theS. aureusisolates produced biofilm which was considered a potential virulence factor in the pathogenesis of staphylococcal mastitis.

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Virulence Factors in Coagulase-Negative Staphylococci

Pathogens ◽

10.3390/pathogens10020170 ◽

2021 ◽

Vol 10 (2) ◽

pp. 170

Author(s):

Angela França ◽

Vânia Gaio ◽

Nathalie Lopes ◽

Luís D. R. Melo

Keyword(s):

Antibiotic Resistance ◽

Virulence Factors ◽

Resistance Genes ◽

Biofilm Formation ◽

Antibiotic Resistance Genes ◽

Coagulase Negative Staphylococci ◽

Healthcare Associated ◽

Major Pathogens

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.

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HMD-ARG: hierarchical multi-task deep learning for annotating antibiotic resistance genes

Microbiome ◽

10.1186/s40168-021-01002-3 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Yu Li ◽

Zeling Xu ◽

Wenkai Han ◽

Huiluo Cao ◽

Ramzan Umarov ◽

...

Keyword(s):

Antibiotic Resistance ◽

Deep Learning ◽

Resistance Genes ◽

Antibiotic Resistance Genes ◽

Third Party ◽

Superior Performance ◽

Beta Lactamase ◽

Learning Framework ◽

Sequence Encoding ◽

Global Threat

Abstract Background The spread of antibiotic resistance has become one of the most urgent threats to global health, which is estimated to cause 700,000 deaths each year globally. Its surrogates, antibiotic resistance genes (ARGs), are highly transmittable between food, water, animal, and human to mitigate the efficacy of antibiotics. Accurately identifying ARGs is thus an indispensable step to understanding the ecology, and transmission of ARGs between environmental and human-associated reservoirs. Unfortunately, the previous computational methods for identifying ARGs are mostly based on sequence alignment, which cannot identify novel ARGs, and their applications are limited by currently incomplete knowledge about ARGs. Results Here, we propose an end-to-end Hierarchical Multi-task Deep learning framework for ARG annotation (HMD-ARG). Taking raw sequence encoding as input, HMD-ARG can identify, without querying against existing sequence databases, multiple ARG properties simultaneously, including if the input protein sequence is an ARG, and if so, what antibiotic family it is resistant to, what resistant mechanism the ARG takes, and if the ARG is an intrinsic one or acquired one. In addition, if the predicted antibiotic family is beta-lactamase, HMD-ARG further predicts the subclass of beta-lactamase that the ARG is resistant to. Comprehensive experiments, including cross-fold validation, third-party dataset validation in human gut microbiota, wet-experimental functional validation, and structural investigation of predicted conserved sites, demonstrate not only the superior performance of our method over the state-of-art methods, but also the effectiveness and robustness of the proposed method. Conclusions We propose a hierarchical multi-task method, HMD-ARG, which is based on deep learning and can provide detailed annotations of ARGs from three important aspects: resistant antibiotic class, resistant mechanism, and gene mobility. We believe that HMD-ARG can serve as a powerful tool to identify antibiotic resistance genes and, therefore mitigate their global threat. Our method and the constructed database are available at http://www.cbrc.kaust.edu.sa/HMDARG/.

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Molecular characteristics and virulence gene profiles of Staphylococcus aureus isolates in Hainan, China

BMC Infectious Diseases ◽

10.1186/s12879-019-4547-5 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 8

Author(s):

Xuehan Li ◽

Tao Huang ◽

Kai Xu ◽

Chenglin Li ◽

Yirong Li

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Resistance Genes ◽

Virulence Genes ◽

Mainland China ◽

Geographical Location ◽

Antibiotic Resistance Genes ◽

Virulence Gene ◽

Molecular Characteristics ◽

Staphylococcal Protein A

Abstract Background There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus (S. aureus) from Hainan, the southernmost province of China. Methods Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013–2014 and 2018–2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. Results Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A (spa) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018–2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCCmec) typing. SCCmec-IVa was the predominant SCCmec type, and specifically, ST45-SCCmec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin (pvl) and eta, were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. Conclusion S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.

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Molecular detection of antibiotic resistance genes in multidrug-resistant Staphylococcus aureus isolates from dog dental plaque

BULGARIAN JOURNAL OF VETERINARY MEDICINE ◽

10.15547/bjvm.2099 ◽

2019 ◽

Vol 22 (4) ◽

pp. 419-427

Author(s):

S. Nouri Gharajalar ◽

M. Onsori

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Multiplex Pcr ◽

Resistance Genes ◽

Dental Plaque ◽

Antibiotic Resistance Genes ◽

Multidrug Resistant ◽

Diffusion Method ◽

Pcr Assay ◽

Multiplex Pcr Assay

Multidrug resistant Staphylococcus aureus strains are a major health care problem both in humans and animals. In this work we described three multiplex PCR assays for detection of clinically relevant antibiotic resistance genes in S. aureus isolated from dog dental plaques. Thirty dental plaque samples were collected; then cultural, biochemical and molecular tests performed for isolation and identification of S. aureus from samples. The antibiotic susceptibility of the isolates were checked by Kirby Bauer disc diffusion method and the prevalence of antibiotic resistance genes determined using multiplex PCR assay. As a result S. aureus was isolated from 18 dog plaque samples. Fifteen of these isolates were resistant to penicillin. The mecA gene was more prevalent than blaZ among penicillin-resistant bacteria. Ten of the isolates were resistant to tetracycline. The percentage of tetM was higher than tetK among them. Also, 10 of the isolates were resistant to cefazolin among them bla TEM detected in higher rate than blaSHV and blaOXA-1. Hence multiplex PCR assay is a suitable method for detection of antibiotic resistance patterns of S. aureus isolates.

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