scholarly journals Detection of enterotoxigenic genes and mecA gene in Staphylococcus aureus isolated from goat milk

2020 ◽  
Vol 6 (7) ◽  
pp. 45692-45703
Author(s):  
Germana Guimarães Rebouças ◽  
Maria Rociene Abrantes ◽  
Manoela de Oliveira Rebouças ◽  
Bruno Vinicios Silva de Araújo ◽  
Sidnei Miyoshi Sakamoto ◽  
...  
2012 ◽  
Vol 13 (2) ◽  
pp. 152-159 ◽  
Author(s):  
Nazar M Abdalla ◽  
Waleed O Haimour ◽  
Amani A Osman ◽  
Hassan Abdul Aziz

General objectives: This study aimed at assessment of factors affecting antimicrobial sensitivity in Staphylococcus aureus clinical isolates from Assir region, Saudi Arabia. Materials and Methods: In this study, eighty one patients presented with Staph. aureus infections either nosocomial or community acquired infections were involved by collecting nasal swabs from them at Aseer Central Hospital General Lab. These patients were from all age groups and from males and females during the period of Jan 2011- Jun 2011. These samples were undergone variable laboratory procedures mainly; bactech, culture media, antibiotics sensitivity test using diffusion disc test (MIC) and molecular (PCR) for detection of mec A gene. Clinical and laboratory data were recorded in special formats and analyzed by statistical computer program (SPSS). Results: Showed that; Descriptive and analytical statistical analysis were performed and final results were plotted in tables. In Staph aureus MecA gene positive cases (50) showed: Oxacillin/ Mithicillin, Ciprofloxacin and Fusidin resistant in diabetic patients were 13, 26.0%, 9, 18% and 7, 14% respectively and in non diabetic patients were 37, 74.0%, 22, 44% and 20, 40% respectively. While no sensitivity in diabetic and non diabetic patients using Oxacillin/ Mithicillin. In Staph aureus MecA gene negative cases (31) showed: Oxacillin/ Mithicillin, sensitivity in diabetic patients (5, 16.1%) and in non diabetic were (26, 83.9%). While no resistant in diabetic and non diabetic patients. In Ciprofloxacin and Fusidin resistant in diabetic patients were 1, 3.2% and 1, 3.2% respectively and in non diabetic patients were 12, 38.7% and 7, 22.6%respectively. Erythromycin in Staph aureus ( MecA gene) positive cases (50) showed: resistant in age (0-15) years were (5, 10%), (16-50) years were (16, 32%) and ( ›50 years) were (12, 24%). Erythromycin in Staph aureus (MecA gene) negative cases (31) showed: resistant in age (0-15) years were (6, 19.3%), (16-50) years were (5, 16.1%) and ( ›50 years) were (3, 9.7%). Conclusion: Drugs resistance is a major progressive multifactorial problem facing the treatment of Staph aureus infections. DOI: http://dx.doi.org/10.3329/jom.v13i2.12750 J Medicine 2012; 13 : 152-159


2021 ◽  
Vol 14 (5) ◽  
pp. 420
Author(s):  
Tanveer Ali ◽  
Abdul Basit ◽  
Asad Mustafa Karim ◽  
Jung-Hun Lee ◽  
Jeong-Ho Jeon ◽  
...  

β-Lactam antibiotics target penicillin-binding proteins and inhibit the synthesis of peptidoglycan, a crucial step in cell wall biosynthesis. Staphylococcus aureus acquires resistance against β-lactam antibiotics by producing a penicillin-binding protein 2a (PBP2a), encoded by the mecA gene. PBP2a participates in peptidoglycan biosynthesis and exhibits a poor affinity towards β-lactam antibiotics. The current study was performed to determine the diversity and the role of missense mutations of PBP2a in the antibiotic resistance mechanism. The methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples were identified using phenotypic and genotypic techniques. The highest frequency (60%, 18 out of 30) of MRSA was observed in wound specimens. Sequence variation analysis of the mecA gene showed four amino acid substitutions (i.e., E239K, E239R, G246E, and E447K). The E239R mutation was found to be novel. The protein-ligand docking results showed that the E239R mutation in the allosteric site of PBP2a induces conformational changes in the active site and, thus, hinders its interaction with cefoxitin. Therefore, the present report indicates that mutation in the allosteric site of PBP2a provides a more closed active site conformation than wide-type PBP2a and then causes the high-level resistance to cefoxitin.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 196
Author(s):  
Beverly Egyir ◽  
Jeannette Bentum ◽  
Naiki Attram ◽  
Anne Fox ◽  
Noah Obeng-Nkrumah ◽  
...  

Staphylococcus aureus (S. aureus) is a common cause of surgical site infections (SSIs) globally. Data on the occurrence of methicillin-susceptible S. aureus (MSSA) as well as methicillin-resistant S. aureus (MRSA) among patients with surgical site infections (SSIs) in sub-Saharan African are scarce. We characterized S. aureus from SSIs in Ghana using molecular methods and antimicrobial susceptibility testing (AST). Wound swabs or aspirate samples were collected from subjects with SSIs. S. aureus was identified by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF-MS); AST was performed by Kirby-Bauer disk diffusion, and results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guideline. Detection of spa, mecA, and pvl genes was performed by polymerase chain reaction (PCR). Whole-genome sequencing (WGS) was done using the Illumina MiSeq platform. Samples were collected from 112 subjects, with 13 S. aureus isolates recovered. Of these, 92% were sensitive to co-trimoxazole, 77% to clindamycin, and 54% to erythromycin. Multi-drug resistance was detected in 5 (38%) isolates. The four mecA gene-positive MRSA isolates detected belonged to ST152 (n = 3) and ST5 (n = 1). In total, 62% of the isolates were positive for the Panton-Valentine leukocidin (pvl) toxin gene. This study reports, for the first time, a pvl-positive ST152-t355 MRSA clone from SSIs in Ghana. The occurrence of multi-drug-resistant S. aureus epidemic clones suggests that continuous surveillance is required to monitor the spread and resistance trends of S. aureus in hospital settings in the country.


2016 ◽  
Vol 79 (4) ◽  
pp. 682-686 ◽  
Author(s):  
LÍVIA G. BAPTISTÃO ◽  
NATHALIA C. C. SILVA ◽  
ERIKA C. R. BONSAGLIA ◽  
BRUNA F. ROSSI ◽  
IVANA G. CASTILHO ◽  
...  

ABSTRACT The hands and noses of food handlers colonized by Staphylococcus aureus are an important source of food contamination in restaurants and food processing. Several virulence factors can be carried by mobile elements in strains of S. aureus, including the immune evasion cluster (IEC). This gene cluster improves the capacity of S. aureus to evade the human immune response. Many studies have reported the transmission of strains between animals and humans, such as farm workers that have close contact with livestock. However, there are few studies on the transmission between food and food handlers. The aim of this study was to detect the IEC and the mecA gene in strains isolated from food handlers and to type these strains using the spa typing method. Thirty-five strains of S. aureus isolated from the noses and hands of food handlers in three different kitchens were analyzed for the presence of the mecA gene and IEC and by spa typing. All strains were negative for the mecA gene, and the presence of IEC was observed in 10 (28.6%) strains. Fifteen different spa types were observed, with the most frequent being t127 (42.85%) and t002 (11.42%). Strains from the two most prevalent spa types and a novel spa type were typed by multilocus sequence typing. spa types t127, t002, and t13335 were determined to be multilocus sequence types (ST) ST-30, ST-5, and ST-45, respectively. The food handlers may have been contaminated by these strains of S. aureus through food, which is suggested by the low frequency of IEC and by ST that are observed more commonly in animals.


2021 ◽  
Vol 15 (2) ◽  
pp. 140-145
Author(s):  
Amanda Pereira Lucas ◽  
Andriele Renata Barbosa de Farias ◽  
Elizabete Cristina da Silva ◽  
Kleber Régis Santoro ◽  
Marcelo Mendonça ◽  
...  

There are few reports in the literature about genetic determinants of resistance to β-lactams in Staphylococcus aureusisolated from dairy cattle located in the municipality of Garanhuns, state of Pernambuco, Brazil. Thus, this study aimed to investigate the production of β-lactamase and the presence of the blaZ and mecA genes in penicillin-resistant S. aureus isolated from cases of subclinical bovine mastitis in the city of Garanhuns. Forty-six strains of penicillin-resistant S. aureus were evalu-ated using the nitrocefin disc test and duplex PCR. The results revealed that 45 strains (97.8%) were positive for β-lactamase production and 44 (95.7%) carried the blaZ gene. Among the latter, 43 (97.7%) were β-lactamase producers and only one (2.3%) was not. The mecA gene was not detected in any of the isolates investigated. The results suggest that enzymatic inacti-vation is the main β-lactam resistance mechanism expressed by S. aureus in the herds analyzed.


2021 ◽  
Vol 28 (1) ◽  
pp. 66-74
Author(s):  
D.A. Oche ◽  
U. Abdulrahim ◽  
A.S. Oheagbulem ◽  
B.O. Olayinka

Biofilm formation and resistance to methicillin are among the factors that makes Staphylococcus aureus a very important human pathogen in both health-care and community settings. This study investigated methicillin-resistance among biofilm-producing S. aureus isolated from 49 orthopaedic in-patients within a 3 months period. Wound swabs, nasal swabs, bed swabs and urine samples were collected from each patient. The samples were cultured and screened for presence of S. aureus while the micro-titre plate method was used to detect biofilm producing isolates. PCR technique was finally used to detect the presence of mecA gene in methicilin resistant S. aureus (MRSA) isolates. Findings reveal 14.8% of bacterial isolates were Staphylococcus aureus of which 96.4% were biofilm-producers. However, strong biofilm producers constitute 11.1%. The mecA gene was detected in 15.8% of the MRSA isolates. Therefore, MRSA among biofilm-producing S. aureus is a potential threat primarily to the community of National Orthopaedic Hospital Dala and a major public health challenge. Keywords: Biofilm, Methicillin-resistance Staphylococcus aureus (MRSA), mecA gene, Orthopaedic patient


Author(s):  
Shamim Rahman ◽  
Ragini Ananth Kashid

MRSA causes nosocomial and community based infections. It is associated with significant mortality and morbidity. Resistance in MRSA is encoded by mecA gene. Anterior nares are the ecological niche of Staphylococcus aureus. HCWs who are colonized with MRSA, act as agents of cross contamination of hospital and community acquired MRSA. Treating MRSA infections is a therapeutic challenge as it is resistant to beta lactam group of drugs. Therefore, there is a need for rapid and accurate detection of MRSA carriage in HCWs and to understand its antibiotic susceptibility pattern.The objective of the present study is to estimate the occurrence of MRSA in HCWs, using phenotypic and genotypic methods. A prospective study for six months was conducted after obtaining Institutional Ethical Committee clearance. Anterior nasal swabs of those HCWs who gave informed consent were taken processed for culture and sensitivity as per standard protocol. To detect MIC for oxacillin, E-strip method was used. mecA gene detection was done by PCR. A total of 300 HCWs were sampled.14.66% (44/300) of the isolates were identified as Staphylococcus aureus, of which 10 isolates were detected as MRSA. The overall isolation rate of MRSA is 3.33 %(10/300). MRSA carriage was high amongst nurses (5/59, 8.47%), followed by doctors (4/105, 3.80%).Antibiotic sensitivity pattern showed that highest resistance was to penicillin (75%) followed by amoxiclav (70.45 %).9 MRSA isolates were detected as mecA gene positive by PCR. MRSA carriers were decontaminated successfully with 2% mupirocin ointment and 2% chlorhexidine shampoo. This study reiterates the need for rapid and accurate identification of HCWs who have nasal colonization with MRSA, for reinforcing hospital infection control measures and decontamination protocol. This will help prevent the spread of MRSA in our community.


2020 ◽  
Vol 27 (07) ◽  
pp. 1363-1370
Author(s):  
Aneela Khawaja ◽  
Iffat Javed ◽  
Sohaila Mushtaq ◽  
Saeed Anwar ◽  
Faiqa Arshad ◽  
...  

Antimicrobial resistance (AMR) is a devastating question that is threatening the health globally. The extensive and indiscriminative use of antibiotics has evolved a notorious resistance in Staphylococcus aureus.  This resistance developed through possession of mecA gene, which codes for modified penicillin binding protein (PBP2a) and the emergent strain being labeled “methicillin resistant Staphylococcus aureus”. Conventional phenotypic techniques for detection of MRSA rely on standardization of cultural characteristics. The drawbacks of diagnostic error to report MRSA include: poor prognosis, expensive treatment, dissemination of multi-drug resistant strains and even treatment failure. Latex agglutination method can be adopted as a more accurate and quick strategy for rapid detection of methicillin resistance. Objectives: To compare detection of mecA gene in methicillin resistant isolates of Staphylococcus aureus by latex agglutination and PCR; by assessing the sensitivity and specificity of both methods. Study Design: Descriptive Cross-Sectional study. Setting: Pathology Department, Post Graduate Medical Institute, Lahore. Period: From January 2015 to December 2015; according to standard operating procedures at Microbiology laboratory. Material & Methods: A total 713 consecutive, non-duplicate isolates of Staphylococcus aureus were processed. Methicillin resistance was determined using cefoxitin (30mg) by Kirby-Bauer method using CLSI guideline (2016), latex agglutination method; and PCR for mecA gene. Results: The results showed that out of 713 Staphylococcus aureus isolates, 92 (12.90%) isolates were resistant to cefoxitin and were labelled as MRSA. majority MRSA isolates recovered from pus (44.57%) and wound swab (20.65%), followed by blood (13.04%), fluid (8.70%), CSF (4.35%), CVP (3.26%), HVS (3.26%) and tracheal secretion (2.17%). By latex agglutination method, 87 (94.50%) were positive for PBP2a; while on PCR mecA gene was detected only in 82 (89.10%) MRSA isolates. When assessed with PCR (gold standard) the sensitivity and diagnostic accuracy of latex agglutination was 100% and 94.57%, respectively. Conclusion: Latex agglutination test can be employed as rapid and reliable diagnostic technique in MRSA isolates for mecA gene detection, where resources for molecular methods are inadequate. This can effectually lessen the misdiagnosis of resistant strains, and over/ ill-use of antibiotics.


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