Molecular Confirmation of Vancomycin-Resistant Staphylococcus aureus with vanA Gene from a Hospital in Kathmandu

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Meera Maharjan ◽  
Anil Kumar Sah ◽  
Susil Pyakurel ◽  
Sabita Thapa ◽  
Susan Maharjan ◽  

Staphylococcus aureus, a commensal on the skin and in the nasal cavity of humans, is one of the most serious cases of nosocomial infections. Moreover, methicillin-resistant S. aureus (MRSA) is a leading cause of morbidity and mortality worldwide. For the treatment of MRSA infections, vancomycin is considered as a drug of choice. However, the emergence of vancomycin resistance among MRSA isolates has been perceived as a formidable threat in therapeutic management. To estimate the rate of vancomycin-resistant S. aureus (VRSA) and to detect the vancomycin-resistant genes, namely, vanA and vanB, among the isolates, a hospital-based cross-sectional study was conducted from July to December 2018 in Annapurna Neurological Institute and Allied Science, Kathmandu, Nepal. S. aureus was isolated and identified from different clinical samples and processed for antibiotic susceptibility testing by the modified Kirby–Bauer disc diffusion method. The screening of MRSA was performed as per Clinical and Laboratory Standard Institute (CLSI) guidelines. VRSA was confirmed by the minimum inhibitory concentration (MIC) method by employing E-test strips. All the phenotypically confirmed VRSA were further processed to detect the vanA and vanB gene by using the conventional polymerase chain reaction (PCR) method. A total of 74 (20.3%) S. aureus were isolated, and the highest percentage of S. aureus was from the wound samples (36.5%). Of 74 S. aureus isolates, the highest number (89.2%) was resistant to penicillin, and on the other hand, linezolid was found to be an effective drug. Likewise, 45 (60.81%) were found to be MRSA, five (11.11%) were VRSA, and 93.2% of S. aureus isolates showed an MAR index greater than 0.2. Two VRSA isolates (40%) were positive for the vanA gene. The higher prevalence of MRSA and significant rate of VRSA in this study recommend routine surveillance for the MRSA and VRSA in hospital settings before empirical therapy.


Objectives: Staphylococcus aureus is often linked with human infection. Clindamycin is one of the key substitute antimicrobial agents in the treatment of S. aureus, especially in methicillin-resistant S. aureus (MRSA) infections. Inducible macrolide-lincosamide-streptogramin B (iMLS B) resistance is a crucial factor in antimicrobial susceptibility testing. The intention of the research was to identify S. aureus from distinct clinical specimens and investigate the prevalence of inducible clindamycin resistance among them and also study their association with MRSA. Methods: A descriptive cross-sectional study was accomplished in the Dept. of Microbiology CMC-TH, Nepal from January 2018 to December 2020 with 525 non-repeated S. aureus obtained from a different clinical specimen. Antibiotic susceptibility test was performed by Kirby–Bauer disc diffusion method. MRSA was detected using cefoxitin (30 μg) and results were interpreted as stated by CLSI. “D-Test” was done by applying erythromycin (15 μg) and clindamycin (2 μg) as per CLSI guidelines. Data were analyzed using SPSS IBM version 20. Results: Among 525 isolates, there were 315 (60.00%) MRSA. Results of D test analysis showed that 280 (53.33%) were MLSB sensitive while 245 (46.67%) were MLSB resistant; where 80 (15.24%) iMLSB with D zone, 100 (19.05%) constitutive MLSB (cMLSB) phenotype, and 65 (12.38%) MS phenotype. Of a total of 80 iMLSB, a significant proportion of 64 (80.00%) was MRSA (p<0.001). All the isolates were sensitive to vancomycin, teicoplanin, and linezolid. The prevalence of both iMLSB and cMLSB was high among MRSA. Conclusion: In this study, cMLSB phenotype was predominant (19.05%) followed by iMLSB phenotype (15.25%) and then MS phenotype (12.38%). Inducible iMLS B phenotypes, as well as cMLSB, are higher among MRSA. It is advisable to include “D-Test” as a part of regular antibiotic susceptibility testing to detect iMLSB resistance among S. aureus.

2019 ◽  
Vol 2 (1) ◽  
Cynthia N Nwaogaraku

Antibiotic resistance is common among pathogenic bacteria associated with community acquired and nosocomial infections. Methicillin-resistant Staphylococcus aureus (MRSA) infections have become a global health problem particularly in hospital setup causing simple skin infections to life threatening infections. The present study aimed to investigate the presence of mecA genes in MRSA from pigs, using Polymerase Chain Reaction. One hundred S. aureus isolates of blood samples from Pigs in Bariga, Lagos State were collected from Molecular Biology and Biotechnology Unit, Nigeria Institute of Medical Research. Methicillin resistance was determined by Kirby-Bauer’s disc diffusion method. The PCR was used for mecA gene detection from MRSA strains. Twenty-five pure Staphylococcus aureus isolates were identified based on cultural characteristics, biochemical reactions and positive slide coagulase test. Out of these, 11 (44%) strains were MRSA by phenotypic method. Amplification of mecA gene for all the 11 MRSA isolates was negative when visualized on 2% agarose gel electrophoresis. Eleven strains of MRSA were found among Staphylococcus aureus isolates of blood samples from Pigs. The MRSA phenotype observed in the isolates was not the classical mecA mediated resistance. Hence, it is highly recommended to consider alternative mechanisms for β-lactams resistance that may compete with mecA gene in the emergence of MRSA phenomenon in Nigeria.

Fibhaa Syed ◽  
Nasim Akhtar ◽  
Mohammad Ali Arif ◽  
Adil Ramzan ◽  
Rauf Niazi ◽  

Abstract Objective: To determine the nasal carriage of staphylococcus aureus and methicillin-resistant staphylococcus aureus among healthcare workers in a tertiary care setting. Methods: The cross-sectional study was conducted at the Pakistan Institute of Medical Sciences, Islamabad, Pakistan, from April to July 2018, and comprised healthcare workers at the institution. Nasal swabs were collected and cultured on Mannitol salt agar. Mannitol fermenting colonies which were gram-positive cocci, catalase-positive and coagulase-positive were identified as staphylococcus aureus. Antibiotic susceptibility test was performed by modified Kirby-Bauer disc diffusion method. Methicillin resistance was detected using cefoxitin disc diffusion method. Data was analysed using SPSS 23. Results: Of the 210 nasal swabs, 52(24.76%) had a staphylococcus aureus growth, and, of them, 15(7.1%) were methicillin-resistant. No association could be established with either any single category of healthcare worker or an inter-department variation (p>0.05). Likewise, there was no association with age, gender, duration of service, smoking, co-morbidities, use of antibiotics in the preceding six months, treating a patient with methicillin-resistant staphylococcus aureus in the preceding six months and hospitalisation in the preceding year (p>0.05). Conclusion: The frequency of nasal carriage of methicillin resistant staphylococcus aureus amongst healthcare workers was regardless of the nature of their professional engagement. Key Words: Methicillin resistant staphylococcus aureus, Nasal carriage, Continuous...

2021 ◽  
Vol 2 (1) ◽  
pp. 52-56
Mohammed M Manga ◽  
Gloria O Michael ◽  
Aishatu A Julde ◽  
Gidado Muhammad ◽  
Umar M Hassan ◽  

Introduction: Antimicrobial resistance (AMR) is a major threat to patient safety. Methicillin and inducible clindamycin resistant Staphylococcus aureus are important multidrug resistant organisms (MDROs). Timely reporting of MDROs is necessary for rational antibiotic prescription and in combating AMR. We present the prevalence and distribution of Methicillin and inducible clindamycin resistant (iCR) isolates of Staphylococcus aureus from Gombe Nigeria. Materials and Methods: This descriptive cross-sectional study included 260 isolates of Staphylococcus aureus from clinical specimens in Federal Teaching Hospital Gombe (FTHG). Isolates identification was done using conventional biochemical methods. Methicillin resistance was detected by cefoxitin disc diffusion method while iCR isolates by erythromycin and clindamycin disc approximation test (D-test). Data analysis was done using SPSS version 23.0. Results: Methicillin resistant Staphylococcus aureus (MRSA) was detected in 178 (68.5%) isolates while 214 (82.3%) were iCR (D-test positive). Among the MRSA, 87.1% were also iCR while 72.4% of the iCR isolates were MRSA. There was significant association between MRSA and iCR (p = 0.03), MRSA and clindamycin resistance (p = 0.05) and MRSA and erythromycin resistance (p < 0.01). Conclusion: Prevalence of MDR Staphylococcus aureus is high in Gombe Nigeria. Antimicrobial stewardship programme (ASP) and good Infection Prevention and Control (IPC) are necessary in combating AMR and improving patient safety.

2019 ◽  
Vol 70 (2) ◽  
pp. 1487
T. E. MUS ◽  
R. CIBIK ◽  

The study was performed to determine the presence of vancomycin phenotyping genes and some virulence traits in enterococci species. For this purpose, a total of 42 enterococci including 6 vancomycin-resistant and 36 vancomycin-susceptible strains originated from meat/meat products and milk/dairy products were assessed for the vanA, vanB and vanC genes and agg, esp, gelE, ace and efaA virulence genes by using polymerase chain reaction or multiplex polymerase chain reaction. The vanA gene was found in 12% (n=5) of the strains and vanC gene in 50% (n=21). From these, three vanA- (E. faecalis, E. durans, E. casseliflavus) and two vanC-positive (E. durans) strains had a minimum inhibitory concentration of > 256 μg/ml as previously determined with the E-test. The strains expressing vancomycin susceptibility originating from ready-to-eat food were found to carry vanA (n=1) and vanC (n=5) genes. On the other hand, the vanB gene was not detected among strains. Moreover, no strain was found to harbor virulence traits studied. Our results indicated that resistant or susceptible enterococci from foods of animal origin can be a possible reservoir for resistance genes and may have a potential role for transfer of genetic elements among enterococci or to other bacteria. Furthermore, to develop epidemiological surveillance systems for foodborne antibiotic resistant pathogens as vancomycin-resistant enterococci and their genes responsible for resistance, primarily vanA, vanB, continues to be an essential issue all around the world. The present work provides data for foodborne enterococci isolates harboring vanA gene from Turkey.

2011 ◽  
Vol 8 (4) ◽  
pp. 947-955 ◽  
Baghdad Science Journal

Rapid and accurate identification of Methicillin Resistant Staphylococcus aureus is essential in limiting the spread of this bacterium. The aim of study is the detection of Methicillin Resistant Staphylococcus aureus (MRSA) and determining their susceptibility to some antimicrobial agent. A total of fifty clinical Staphylococcus aureus, isolated from the nose of health work staff in surgery unit of Kalar general hospital and from ear of patients attended to the same hospital. The susceptibilities of isolates were determined by the disc diffusion method with oxacillin (1 ?g) and cefoxitin (30 ?g), and by the mannitol salt agar supplemented with cefoxitin (MSA-CFOX), susceptibilities of isolates to other antimicrobial agent were determined by standard disc diffusion method, Brain heart infusion (BHI) agar with vancomycin was used for detection of vancomycin resistant Staphylococcus aureus. out of fifty clinical isolates of Staphylococcus aureus 36/50(72%) considered to be MRSA according to MSA-CFOX growth and cefoxitin disc susceptibility results with critical diameter

2021 ◽  
Vol 4 (1) ◽  
Upasana Ghimire ◽  
Rupesh Kandel ◽  
Mary Neupane ◽  
Sanjit Shrestha ◽  
Sudeep K C ◽  

(1) Background: Acinetobacter baumannii has emerged as a leading cause of nosocomial infections as they are capable of evolving resistance to various classes of antibiotics. The ability of A. baumannii to form biofilm might also be associated with increased antibiotic resistance and hence treatment failure. This study was carried to associate the biofilm formation with the drug resistance pattern of A. baumannii and to detect blaOXA-23, blaOXA-24, and blaOXA-51 from carbapenem resistance isolates. (2) Methods: Among different clinical samples, a total of 19 Acinetobacter spp. were identified with conventional microbiological procedures. The biofilm production was determined by a quantitative adherence assay. The antimicrobial susceptibility test was carried out by the Kirby-Bauer disc diffusion method, carbapenemase production detection was confirmed by Modified Hodge Test. And target resistant genes were detected by polymerase chain reaction. (3) Results: Out of 90 clinical specimens, 64.44% (58/90) showed bacterial growth. Whereas, 32.75% (19/58) isolates were identified as A. baumannii. Among all A. baumannii isolates, 84.21% (16/19) were multidrug-resistance and 63.16% (12/19) carbapenem resistance phenotypically. blaOXA-51 was detected in all the isolates and blaOXA-23 was detected only in 63.16% (12/19) isolates. However, blaOXA-24 was not detected in any of the isolates. Among A. baumannii, 89.47% (17/19) isolates produced biofilm with 47.37% (9/19) strong biofilm producers. (4) Conclusions: In the majority of MDR A. baumannii, blaOXA-51 and blaOXA-23 were detected as the determinant factor for carbapenem resistance having a direct relation with biofilm formation. This study provided a valuable clue for the management of A. baumannii infections in clinical settings.  

2016 ◽  
Vol 37 (4) ◽  
pp. 440-447 ◽  
Miriam D. Ismail ◽  
Ting Luo ◽  
Sara McNamara ◽  
Bonnie Lansing ◽  
Evonne Koo ◽  

BACKGROUNDRates of multidrug-resistant gram-negative organisms are surpassing those of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in nursing homes (NHs).OBJECTIVETo characterize the incidence and duration of carriage of ciprofloxacin-resistant Escherichia coli (CipREc) in NHs and identify those in the O25b-ST131 lineage.METHODSWe collected 227 CipREc isolates obtained by routine and regular surveillance of high-risk NH residents with indwelling devices. Repetitive element palindromic (REP)–polymerase chain reaction assay and multiplex polymerase chain reaction amplification for O25b-ST131 E. coli detection were performed using (GTG)5-primers and O25pabBspe and trpA2 primer pairs, respectively.RESULTSWe found a high period prevalence of CipREc colonization (21.5%), high rates of recolonization with the same strain following clearing (0.46 recolonizations/ person/ year), and an acquisition incidence of 1.05 cases/1,000 person-days. Almost three-quarters of colonized residents carried strains in the O25b-ST131 E. coli lineage. Compared with isolates not in the lineage, O25b-ST131 isolates were carried significantly longer (10 vs 3 months). We identified 18 different REP-types; 2 occurred in 55% of the residents colonized with CipREc, and in more than 1 NH. Duration of CipREc carriage varied by REP-type and averaged 6 months.CONCLUSIONCipREc occurred frequently in NH residents and is carried for long durations, and reacquisition following clearance is commonTrial registration. identifier: NCT01062841.Infect. Control Hosp. Epidemiol. 2016;37(4):440–447

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