scholarly journals Phenotypic study of Macrolide-Lincosamide-Streptogramin B Resistance in Staphylococcus aureus and their relationship with Methicillin-Resistant Staphylococcus aureus (MRSA) at Tertiary Care in Eastern Nepal

2016 ◽  
Vol 5 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Ganesh Kumar Singh ◽  
Bigu Kumar Chaudhari ◽  
Kamal Prasad Parajuli
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tertiary Care ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
Constitutive Resistance ◽  
Antibiotic Susceptibility Test

Background Resistance to antimicrobial agents is prevalent among Staphylococci. This has led to wide uses of macrolide-lincosamide-streptogramin B (MLSB) antibiotics to Staphylococcus aureus (S. aureus) infections. MLSB though chemically distinct, have similar target site and mode of action. The multiple mechanisms are responsible for resistance to MLSB antibiotics which can lead to clinical failure. The aim of the study was to investigate the frequency of inducible and constitutive clindamycin resistance among clinical isolates of S. aureus and their relationship with Methicillin-resistant Staphylococcus aureus (MRSA).Material & Methods A total of 336 unique Staphylococcus aureus isolates from different clinical samples obtained from patients were studied. Antibiotic susceptibility test was performed by Kirby- Bauer disc diffusion method. “D test” was performed to detect inducible clindamycin resistance as per CLSI guidelines. MRSA was detected using Cefoxitin (30μg) and results were interpreted according to CLSI criteria.Results Inducible clindamycin resistance was seen in 45 (13.39%), constitutive clindamycin resistance was seen among 58 (17.26%) while MS phenotype was observed among 38(11.30%) of isolates. Inducible resistance as well as constitutive resistance was higher among MRSA as compared to MSSA (21.11%, 4.48% and 21.11%, 12.82%respectively).Conclusion The Successful use of clindamycin for the treatment of infection caused by S. aureus can be predicted based on the result of simple and inexpensive D test.Journal of Nobel Medical CollegeVolume 5, Number 1, Issue 8, January-July 2016, 1-5

Phenotypic characterization and Molecular detection of Inducible and Constitutive Clindamycin resistance among Staphylococcus aureus isolates in a Tertiary Care Hospital

2021 ◽  
pp. 3799-3804
Author(s):  
Mahalakshmi G. ◽  
Neelusree P. ◽  
Kalyani M.
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tertiary Care ◽  
Phenotypic Characterization ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Care Hospital ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
Significant Difference

Background: Staphylococcus aureus is Gram positive cocci. The pyogenic bacteria which is responsible for a variety of diseases that ranges in severity from mild skin and soft tissue infections to life-threatening conditions such as endocarditis, pneumonia, and sepsis. There is a scenario of increasing Methicillin-resistant Staphylococcus aureus (MRSA) infections, the macrolide-lincosamide-streptogramin B (MLSB) group of antibiotics they have different structure with same mechanism of action which serves as one good alternative. There is a frequency of increasing Methicillin Resistant Staphylococcus aureus (MRSA) infections and their change in antimicrobial resistance pattern. There is a concern about use of this antibiotic in the presence of Erythromycin resistance because of the possibility of inducible resistance among the members of Macrolide, lincosamide, Strepto-gramin B (MLSB) group. The invitro resistance exhibited by Staphylococcus aureus to erythromycin, Clindamycin, and other drugs of MLSB groups is due to the expression of ribosomal methylases(erm) genes. The detection of inducible Clindamycin resistance can limit the effectiveness of these drugs. Objective of the study: To isolate of Staphylococcus aureus from various clinical samples to differentiate between Methicillin resistant Staphylococcus aureus (MRSA) and Methicillin sensitive Staphylococcus aureus (MSSA) by conventional methods. To detect inducible and constitutive Clindamycin resistance in Staphylococcus aureus isolates by D test. To detect ermA gene responsible for resistance by PCR. Methodology: This cross sectional study was done for a period of six months. Totally 106 Staphylococcus aureus isolates was obtained various clinical samples were processed using standard guidelines. Result: From the 106 isolates of Staphylococcus aureus 67(63.3%) were MSSA and 39(36.7%) were MRSA. D-test was positive in n=9 of the n=21 MRSA and n=17 of the n=85 MSSA, which denotes inducible Clindamycin resistance. N- 9 of MRSA and n=13(22%) of MSSA showed Constitutional Clindamycin resistance. The statistics show that there is a significant Difference in constitutive resistance between MRSA and MSSA. In India ermA gene is most prevalent, out of 22 d-test positive n=13 ermA gene were detected (n=3-MRSA and n=10-MSSA) by using conventional PCR. Conclusion: The MLSB family of antibiotics is one such alternative and CD is preferred. Clinical microbiology laboratories should report inducible Clindamycin resistance in Staphylococcus aureus and D-test can be used as a simple, auxiliary and reliable method to Delineate inducible and constitutive Clindamycin resistance in routine clinical laboratories.

scholarly journals Inducible Clindamycin Resistance in Staphylococcus aureus Isolated from Clinical Samples

2011 ◽  
Vol 3 (01) ◽  
pp. 025-027 ◽  
Author(s):  
Kavitha Prabhu ◽  
Sunil Rao ◽  
Venkatakrishna Rao
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Disc Diffusion ◽  
Gene Encoding ◽  
Inducible Clindamycin Resistance ◽  
Inducible Resistance ◽  
Constitutive Resistance

ABSTRACT Introduction: The resistance to antimicrobial agents among Staphylococci is an increasing problem. This has led to renewed interest in the usage of Macrolide-Lincosamide-Streptogramin B (MLS B ) antibiotics to treat Staphylococcus aureus (S. aureus) infections. The resistance to macrolide can be mediated by msr A gene coding for efflux mechanism or via erm gene encoding for enzymes that confer inducible or constitutive resistance to MLS B antibiotics. In vitro routine tests for clindamycin susceptibility may fail to detect inducible clindamycin resistance due to erm genes resulting in treatment failure, thus necessitating the need to detect such resistance by a simple D test on a routine basis. Materials and Methods : One hundred and ninety S. aureus isolates were subjected to routine antibiotic susceptibility testing including oxacillin (1 µg) and cefoxitin (30 µg) by modified Kirby Bauer disc diffusion method. Inducible resistance to clindamycin in S. aureus was tested by ′D test′ as per CLSI guidelines. Results: Twenty (10%) isolates showed inducible clindamycin resistance, 18 (9%) showed constitutive resistance while remaining 16 (8%) showed MS phenotype. Inducible resistance and constitutive resistance were found to be higher in MRSA as compared to MSSA (20%, 16% and 6%, 6%, respectively). Conclusion : Clindamycin is kept as a reserve drug and is usually advocated in severe MRSA infections depending upon the antimicrobial susceptibility results. This study showed that D test should be used as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance in Staphylococci for the optimum treatment of patients.

scholarly journals Prevalence and antimicrobial susceptibility pattern of Methicillin-Resistant Staphylococcus aureus isolated from various clinical samples of the patients attending in a Tertiary Care Teaching Hospital in Puducherry

2019 ◽  
Vol 10 (2) ◽  
pp. 1474-1480
Author(s):  
Vamsi Muni Krishna P ◽  
Sreenivasulu Reddy V ◽  
Praveen Kumar V ◽  
Suresh P
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Tertiary Care ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Isolation And Identification ◽  
Methicillin Resistant ◽  
Antimicrobial Susceptibility Pattern ◽  
Microbiological Methods

Staphylococci spp has been reported as a major cause of hospital and community-associated infections. Staphylococcus aureus is the most common pathogen causing a variety of infections relatively begins minor skin in sections (abscess. cellulitis, staphylococcal scalded skin syndrome) to live threating systemic infections like endocarditis, septic arthritis, pneumonia joint, and bone infections, toxic shock syndrome. Methicillin resistance was reported in 1961 and emerged in the last several decades as one of the most important nosocomial pathogens which were reported just one year of the launch of methicillin. MRSA now a day a big problem is because it is creating life threating problems medical institutions. The knowledge of MRSA prevalence and current antibiogram profile is necessary for the selection of appropriate treatment for related infections. Isolation and identification of Staphylococcus aureus were done by standard conventional microbiological methods. The Methicillin-resistant Staphylococcus aureus strains were tested by using Cefoxitin 30μg disc on Mueller - Hinton agar and antibiotic susceptibility testing were done by Kirby-Bauer disc diffusion method according to Clinical and Laboratory Standards Insititute guidelines (CLSI). All the 164 MRSA (100%) strains were sensitive to Tigecycline, Vancomycin, Teicoplanin followed by Linezolid (92. 68%). Tigecycline, Vancomycin, Teicoplanin has until now excellent activity against clinical isolates of Methicillin-resistant Staphylococcus aureus.

scholarly journals Isolation of mecC Gene carrying Methicillin Resistant Staphylococcus aureus in Clinical Samples from a Tertiary Care Institute, Northern India

2021 ◽  
Author(s):  
Nargis Bali ◽  
Biswajyoti Borkakoty ◽  
Humaira Bashir ◽  
Shaista Nazir ◽  
Sayim Wani ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tertiary Care ◽  
Meca Gene ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Jammu And Kashmir ◽  
Methicillin Resistant

Introduction: The MecC Methicillin Resistant Staphylococcus aureus (MRSA) after its initial recovery in 2007 has been reported with varying frequency from different parts of the world. These isolates assume importance due to the fact that with routine testing platforms available for the detection of MRSA they can be misidentified as being methicillin sensitive which can adversely affect the treatment and outcome of infections due to MRSA harbouring the mecC gene. Aim: To evaluate mecC gene carrying MRSA in clinical isolates. Materials and Methods: This retrospective study was conducted in the Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India for a period of three months (May-July 2020). A total of 102 laboratory confirmed isolates of MRSA (based on biochemical tests and cefoxitin disc diffusion results) were subjected to screening for the presence of mecA and mecC gene by Polymerase Chain Reaction (PCR). Deoxyribonucleic Acid (DNA) was extracted using an in house extraction method following which mecA and mecC were amplified in a total reaction volume of 25 μL using 2x PCR master mix, 5 μL of template and 1 μL (0.4 μM final concentration) each of reverse and forward primers specific for the above mentioned genes. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS) software v24.0. Results: All the isolates were confirmed as being methicillin resistant with 96.1% isolates carrying the mecA gene and 3.9% carrying the mecC gene. The mecC MRSA were recovered from pus, swab and endotracheal tip in middle aged men. One of the patient from whose sample mecC MRSA was recovered was suffering from hypertension, diabetes and renal faliure. MRSA exhibited high resistance to all the antimicrobial agents tested however all of them were sensitive to vancomycin and linezolid. Conclusion: The presence of mecC gene in clinical isolates of MRSA is a cause of concern and calls for an extensive and continuous surveillance of such isolates as they can in future be implicated in causing severe human infections.

scholarly journals Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Karinne Spirandelli Carvalho Naves ◽  
Natália Vaz da Trindade ◽  
Paulo Pinto Gontijo Filho
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Bloodstream Infection ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Staphylococcus Aureus Bloodstream Infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

scholarly journals Antibiotic Susceptibility Pattern of Nosocomial Isolates of Staphylococcus aureus in a Tertiary Care Hospital, Nepal

2009 ◽  
Vol 48 (175) ◽  
Author(s):  
Bidya Shrestha ◽  
B M Pokhrel ◽  
T M Mohapatra
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tertiary Care ◽  
Test Method ◽  
University Teaching ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Care Hospital ◽  
Biochemical Tests ◽  
Methicillin Resistant

Introduction: Methicillin resistant Staphylococcus aureus (MRSA), the most common cause ofnosocomial infection has been a major cause of morbidity and mortality around the world. They arenormally resistant to most of the antibiotics used in clinical practice. This study has been carried outto fi nd out the resistance pattern among S. aureus.Methods: During November 2007 to June 2008, clinical samples from patients with nosocomialinfection were processed for culture and sensitivity following standard methodology in microbiologylaboratory, Tribhuvan University teaching hospital, Kathmandu, Nepal.Results: Among 149 Staphylococcus aureus isolates, highest resistance was observed against Penicillin(91.94%) followed by Fluoroquinolone (61.74%), Erythromycin (52.94%), Gentamicin (46.98%),Cotrimoxazole (42.95%), Tetracycline (40.94%) and others, whereas susceptibility was observedmaximum against Chloramphenicol (94.85%) followed by Rifampicin (92.61%), Tetracycline(59.06%), Cotrimoxazole (57.04%), and others. None of the isolates were resistant to Vancomycinand Teicoplanin. Of these isolates 44.96 % of the isolates were Methicillin resistant S. aureus (MRSA).Resistance to Penicillin, Fluoroquinolone, Erythromycin, Gentamicin, Co-trimoxazole and Tetracyclinewere associated signifi cantly with MRSA isolates (X2= 8.779, p<0.05, X2= 74.233, p<0.05, X2= 84.2842,p<0.05, X2= 108.2032, p<0.05, X2= 88.1512, p<0.05 and X2= 79.1876, p<0.05 respectively). Althoughmost of the Methicillin sensitive S. aureus (MSSA) isolates were susceptible to both Rifampicinand Chloramphenicol, only Rifampicin susceptibility was signifi cantly associated with them (X2=10.1299, p<0.05). Among three Biochemical tests for the detection of β lactamase detection namelychromogenic, iodometric and acidimetric test, chromogenic test method had highest sensitivity andspecifi city.Conclusions: Since MRSA comprised a greater part of S. aureus isolates and were multi-resistant,patients infected by such strains should be identifi ed and kept in isolation for hospital infectioncontrol and treated with second line of drug like vancomycin.Key Words: β lactamase, methicillin resistant Staphylococcus aureus,methicillin sensitive Staphylococcus aureus, resistance pattern

scholarly journals Genetic Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Human Bloodstream Infections: Detection of MLSB Resistance

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 375
Author(s):  
Vanessa Silva ◽  
Sara Hermenegildo ◽  
Catarina Ferreira ◽  
Célia M. Manaia ◽  
Rosa Capita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bloodstream Infections ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Accessory Gene ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant

In this study we aimed to characterize antimicrobial resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolated from bloodstream infections as well as the associated genetic lineages of the isolates. Sixteen MRSA isolates were recovered from bacteremia samples from inpatients between 2016 and 2019. The antimicrobial susceptibility of these isolates was tested by the Kirby–Bauer disk diffusion method against 14 antimicrobial agents. To determine the macrolide–lincosamide–streptogramin B (MLSB) resistance phenotype of the isolates, erythromycin-resistant isolates were assessed by double-disk diffusion (D-test). The resistance and virulence genes were screened by polymerase chain reaction (PCR). All isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal chromosomal cassette mec (SCCmec) typing, and accessory gene regulator (agr) typing. Isolates showed resistance to cefoxitin, penicillin, ciprofloxacin, erythromycin, fusidic acid, clindamycin, and aminoglycosides, confirmed by the presence of the blaZ, ermA, ermC, mphC, msrA/B, aac(6’)-Ie-aph(2’’)-Ia, and ant(4’)-Ia genes. Three isolates were Panton–Valentine-leukocidin-positive. Most strains (n = 12) presented an inducible MLSB phenotype. The isolates were ascribed to eight spa-types (t747, t002, t020, t1084, t008, t10682, t18526, and t1370) and four MLSTs (ST22, ST5, ST105, and ST8). Overall, most (n = 12) MRSA isolates had a multidrug-resistance profile with inducible MLSB phenotypes and belonged to epidemic MRSA clones.

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