Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil

Almeida, Lara Mendes de; Almeida, Mayra Zilta P.R.B. de; Mendonça, Carla Lopes de; Mamizuka, Elsa M.

doi:10.1590/s1517-83822013000200026

Cited by 23 publications

(19 citation statements)

References 33 publications

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“…The primers and amplification conditions of these genes were previously described by Darwish et al ( icaA , icaD ) [ 21 ], Otsuka et al ( fnbpA ) [ 22 ], Tristan et al ( fnbpB , clfA , clfB , cna , bbp ) [ 23 ], Campbell et al ( ebpS , sdrC , sdrD ) [ 24 ], and Peacock et al ( sdrE ) [ 25 ]. N315 was used as positive control for icaA , icaD, ebpS, sdrC,sdrD, and sdrE ; RN4220 was used as positive control for fnbpA , fnbpB , clfA , clfB ; ATCC25923 was used as positive control for cna and bbp [ 26 , 27 ]. The presence and size of the PCR products were confirmed by electrophoresis on 1.5% agarose gels.…”

Section: Methodsmentioning

confidence: 99%

Multiresistant ST59-SCCmec IV-t437 clone with strong biofilm-forming capacity was identified predominantly in MRSA isolated from Chinese children

et al. 2017

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BackgroundThis study aimed to investigate the clinical and molecular epidemiology and biofilm formation of Staphylococcus aureus (SA) isolated from pediatricians in China.MethodsSA strains were isolated from Beijing Children’s hospital from February 2016 to January 2017. Isolates were typed by multilocus sequence typing (MLST), spa and SCCmec typing (for Methicillin-resistant SA [MRSA] only). Antimicrobial susceptibility testing was performed by agar dilution method except sulphamethoxazole/trimethoprim (E-test method). Biofilm formation and biofilm associated genes were detected.ResultsTotally 104 children (41 females and 63 males; median age, 5.2 months) were enrolled in this study, in which 60 patients suffered from MRSA infection. Among the 104 cases, 54.8% were categorized as community associated SA (CA-SA) infections. The children under 3 years were more likely to occur CA-SA infections compared with older ones (P = 0.0131). ST59-SCCmec IV-t437 (61.7%) was the most prevalent genotype of MRSA, and ST22-t309 (18.2%), ST5-t002 (9.1%), ST6-t701 (9.1%), ST188-t189 (9.1%) were the top four genotypes of methicillin-sensitive SA (MSSA). All the present isolates were susceptible to linezolid, vancomycin, trimethoprim-sulfamethoxazole, mupirocin, tigecyclin, fusidic acid. No erythromycin-susceptible isolate was determined, and only a few isolates (3.8%) were identified as susceptible to penicillin. Multi-drug resistant isolates were reponsible for 83.8% of the ST59-SCCmec IV-t437 isolates. The isolates with strong biofilm formation were found in 85% of MRSA and 53.2% of MSSA, and in 88.7% of ST59-SCCmec IV-t437 isolates. Biofilm formation ability varied not only between MRSA and MSSA (P = 0.0053), but also greatly among different genotypes (P < 0.0001). The prevalence of the biofilm associated genes among ST59-SCCmec IV-t437 clone was: icaA (100.0%), icaD (97.3%), fnbpA (100.0%), fnbpB (0), clfA (100%), clfB (100%), cna (2.7%), bbp (0), ebpS (88.5%), sdrC (78.4%), sdrD (5.4%), and sdrE (94.5%). ConclusionsThese results indicated strong homology of the MRSA stains isolated from Chinese children, which was caused by spread of multiresistant ST59-SCCmec IV-t437 clone with strong biofilm formation ability. The MSSA strains, in contrast, were very heterogeneity, half of which could produce biofilm strongly.Electronic supplementary materialThe online version of this article (10.1186/s12879-017-2833-7) contains supplementary material, which is available to authorized users.

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Section: Methodsmentioning

confidence: 99%

Multiresistant ST59-SCCmec IV-t437 clone with strong biofilm-forming capacity was identified predominantly in MRSA isolated from Chinese children

et al. 2017

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“…The prevelance of lukD-lukE was variable in literatures where in a study performed in USA, it was 36.5% (Abdalrahman and Fakhr, 2015). In another study, 82.8%, of isolates were lukD-lukE positive (de Almeida et al, 2013).…”

Section: Discussionmentioning

confidence: 93%

Studies on leukocidins toxins and antimicrobial resistance in Staphylococcus aureus isolated from various clinical sources

Abdel-hamed¹,

Abdel-Rhman²,

El-Sokkary³

2016

Afr. J. Microbiol. Res.

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Staphylococcus aureus toxins represent a public health challenge all over the world. This study aims to analyze the prevalence of genes encoding the staphylococcal leukocidins and their correlation with antimicrobial susceptibility and the source of isolation. For this purpose, the susceptibility of 75 S. aureus isolates to 12 antimicrobial agents was investigated. The leukocidins genes (lukD, lukE, lukF and lukS) were detected by polymerase chain reaction (PCR). The ability to express these genes was assessed among 20 isolates by RT-PCR. The most prevalent luk genes were lukF gene (73.3%), followed by lukE (64%), lukD (44%) and lukS (34.7%). Expression of lukD, lukE and lukS genes were variable. lukF gene was not expressed by any of the tested isolates. A statistically significant association was found between lukF occurrence and burn isolates. Besides that, lukF gene was more prevalent among amoxicillin-clavulenic acid and amikacin resistant isolates, while lukE was predominant with gentamicin resistant isolates. High expression level of lukD was found in MRSA and MDR isolates.

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“…Although, these isolates were obtained from samples with negative results in California mastitis test, and they could be considered healthy, or with no indication of subclinical infection, this fact can contribute to the persistence of infection of subclinical staphylococcal infection in animals. Almeida et al (2013) suggested that the presence of clfA gene, a receptor for fibronectin, is involved in the colonization of the mammary gland epithelium despite the clinical picture of the mastitis. In this study, S. aureus samples isolated from milkers' hands were positive for clfA, clfB and hla genes, and may be a key factor for the maintenance of these virulence factors in these agents causing disease to both human and buffalo.…”

Section: Characterization Of Virulence Related Genesmentioning

confidence: 99%

Identification and production of biofilm by Staphylococcus aureus isolated from buffalo milk and milking environment

Almeida¹,

Pizauro²,

Rossi³

et al. 2017

Afr. J. Microbiol. Res.

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The interest in production of buffalo milk is increasing in Brazil due to its physico-chemical and nutritional characteristics. However, just as sheep, goats and cows are susceptible to mastitis, so are buffaloes, which is mainly caused by Staphylococcus aureus. In this regard, biofilm formation, the ability to escape host immune defense and virulence factor, is presumably a key factor for acute and chronic intra-mammary infection in buffaloes. In this study, biofilm forming capabilities and virulence genes were evaluated in S. aureus isolated from buffalo milk and milking environments, using phenotypic and genotypic assays. Thirty two S. aureus strains isolated from buffalo milk, milking machines and milkers' hands were obtained from a farm in Analândia, São Paulo State, Brazil. Samples were collected in April, June, October and November 2013. These strains were tested for the presence of sa442, icaA, icaD, clfA, clfB, sarA and hla genes, slime production using Congo Red Agar (CRA), and biofilm formation using microtiter assay. All samples of S. aureus were positive for CRA and microtiter assay. Although, icaA and icaD genes were simultaneously detected in nine of the 32 samples, none of the samples were positive for icaA; only seven were positive for icaD gene. This suggests that other factors may be involved in biofilm formation. Seventeen strains of S. aureus were positive for sarA gene, nine for clfA gene, 16 for clfB and 16 for hla. A great variability in SmaI restriction profiles of S. aureus strains was observed. Thirty isolates were typified and two strains were not by SmaI restriction. In addition, 18 pulse types were detected. It is hypothesized that biofilm can be produced by the expression of icaD gene only. Our findings suggest that S. aureus strains from buffalo milk and milking environment are similar, which contradict the findings obtained from bovine strains. This behavior may contribute to the persistence of mastitis in buffalo caused by S. aureus, which results in a potential zoonotic problem. Our results may bring new insights into the development of novel strategies for the prevention and treatment of bubaline mastitis.

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Comparative analysis of agr groups and virulence genes among subclinical and clinical mastitis Staphylococcus aureus isolates from sheep flocks of the Northeast of Brazil

Cited by 23 publications

References 33 publications

Multiresistant ST59-SCCmec IV-t437 clone with strong biofilm-forming capacity was identified predominantly in MRSA isolated from Chinese children

Multiresistant ST59-SCCmec IV-t437 clone with strong biofilm-forming capacity was identified predominantly in MRSA isolated from Chinese children

Studies on leukocidins toxins and antimicrobial resistance in Staphylococcus aureus isolated from various clinical sources

Identification and production of biofilm by Staphylococcus aureus isolated from buffalo milk and milking environment

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