Faculty Opinions recommendation of Practical disk diffusion method for detection of inducible clindamycin resistance in Staphylococcus aureus and coagulase-negative staphylococci.

2003 ◽  
Author(s):  
Gary Lum
Keyword(s):  
Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Coagulase Negative Staphylococci ◽  
Disk Diffusion Method ◽  
Inducible Clindamycin Resistance

scholarly journals A study of inducible clindamycin resistance in erythromycin resistant clinical isolates of Staphylococcus species

2015 ◽  
Vol 6 (6) ◽  
pp. 48-52
Author(s):  
Fatima Khan ◽  
Sana Ali ◽  
Asfia Sultan ◽  
Meher Rizvi ◽  
Abida Khatoon ◽  
...  
Keyword(s):  
Methicillin Resistance ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Clinical Failure ◽  
Coagulase Negative Staphylococci ◽  
Sensitivity Testing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance

Introduction: Erythromycin resistant Staphylococcus isolates with inducible resistance appear sensitive to clindamycin in in?vitro sensitivity testing. If clindamycin is used for treatment of such isolates, selection for constitutive mutants may lead to clinical failure. Current study was conducted to detect the presence of inducible clindamycin resistance in erythromycin resistant Staphylococcus isolates by disk diffusion method (D test). To correlate clindamycin resistance phenotypes with minimum inhibitory concentrations (MICs) of clindamycin, erythromycin, oxacillin and vancomycin among the isolates. To correlate various resistance phenotypes with methicillin resistance. Material and Methods: 150 non duplicate isolates of Staphylococcus species were identified and antibiotic susceptibility testing was done using Kirby Bauer’s disc diffusion method. MICs were determined using E?test for oxacillin, vancomycin, clindamycin and erythromycin using E?test strips (Himedia) Results: Among 150 staphylococcus clinical isolates, 96 were of S. aureus and 54 were coagulase negative Staphylococci (CONS). About 81.2% of the S.aureus isolates and 72.2% of the CONS were found to be methicillin resistant. Inducible clindamycin resistance was found in 39.3% of the isolates, constitutive resistance phenotype in 48% while 12.7% demonstrated MS phenotype. 18% and 11.3% of all the isolates had MICs for clindamycin between 0.01?0.06 μg/ml and 0.06?0.1 respectively. 12.5% had MIC ranging from 4?8 μg/ml while 58% had MIC > 8 μg/ml. Constitutive resistant phenotype (cMLS) was the predominant phenotype in methicillin resistant isolates. MS phenotype was the predominant among MSSA (methicillin sensitive S. aureus) while MSCNS (methicillin sensitive CONS) cMLS (46.7%) predominated. MIC of all erythromycin resistant isolates were ≥ 240 μg/ml. Nearly 16.7% of the cMLS and 57.9% of MS isolates were found to be oxacillin sensitive and 83% of iMLS and 83.3% of MS phenotype isolates were oxacillin resistant on MIC testing. 47.2% of cMLS and 73.6% of MS isolates had MIC ≤ 2 μg/ml for vancomycin and 52.7% of cMLS and 26.3% of MS isolates had MICs in intermediate range for vancomycin. Conclusions: D?testing might help clinicians to decide whether to use clindamycin in Staphylococcal infections when erythromycin resistance is present. Determination of MICs help to identify exact sensitivity profile of isolates in cases where clinical failure occurs due to misleading disk diffusion tests.DOI: http://dx.doi.org/10.3126/ajms.v6i6.11811 Asian Journal of Medical Sciences Vol.6(6) 2015 48-52

scholarly journals  Antibiotic resistance of enterococci, coagulase negative staphylococci and Staphylococcus aureus isolated from chicken meat

2013 ◽  
Vol 31 (No. 1) ◽  
pp. 14-19 ◽  
Author(s):  
N.E. Yurdakul ◽  
Z. Erginkaya ◽  
E. Ünal
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Chicken Meat ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Coagulase Negative Staphylococci ◽  
Disk Diffusion Method ◽  
Enterococcus Spp ◽  
Meat Samples ◽  
And Staphylococcus Aureus

We determined the antibiotic resistance of enterococci, coagulase negative staphylococci, and Staphylococcus aureus isolated from chicken meat samples. The antibiotic resistance of the isolated strains was estimated by the Kirby-Bauer disk diffusion method (according to the NCCLS document M2-A9 suggestions). It was found that all strains of Enterococcus spp. were resistant to tetracycline, 75% of them were resistant to ciprofloxacin, and 50% of them were resistant to erythromycin, vancomycin, and chloramphenicol. Also all strains of S. aureus were resistant to tetracycline and 25% of S. aureus strains were resistant to erythromycin and chloramphenicol, whereas all strains of S. aureus were sensitive to teicoplanin and 25% of them were sensitive to vancomycin and ciprofloxacin. As for the isolate of coagulase negative staphylococci (CNS), 68.1% of them were resistant to erythromycin, 77.2% of them were resistant to tetracycline, 59% of them were resistant to vancomycin, 9% of them were resistant to teicoplanin, and 27.2% of them were resistant to both chloramphenicol and ciprofloxacin. As a result, it was found that most of the strains (all of S. aureus and Enterococcus spp., also 77.2% CNS) were resistant to tetracycline.  

scholarly journals Predominance of PVL-negative community-associated methicillin-resistant Staphylococcus aureus sequence type 8 in newly diagnosed HIV-infected adults, Tanzania

2021 ◽  
Author(s):  
Joel Manyahi ◽  
Sabrina J. Moyo ◽  
Said Aboud ◽  
Nina Langeland ◽  
Bjørn Blomberg
Keyword(s):  
Staphylococcus Aureus ◽  
Hiv Infection ◽  
Diffusion Method ◽  
Molecular Characteristics ◽  
People Living With Hiv ◽  
Newly Diagnosed ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance

AbstractDifficult-to-treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are of concern in people living with HIV infection as they are more vulnerable to infection. We aimed to identify molecular characteristics of MRSA colonizing newly diagnosed HIV-infected adults in Tanzania. Individuals newly diagnosed with HIV infection were recruited in Dar es Salaam, Tanzania, from April 2017 to May 2018, as part of the randomized clinical trial CoTrimResist (ClinicalTrials.gov identifier: NCT03087890). Nasal/nasopharyngeal isolates of Staphylococcus aureus were susceptibility tested by disk diffusion method, and cefoxitin-resistant isolates were characterized by short-reads whole genome sequencing. Four percent (22/537) of patients carried MRSA in the nose/nasopharynx. MRSA isolates were frequently resistant towards gentamicin (95%), ciprofloxacin (91%), and erythromycin (82%) but less often towards trimethoprim-sulfamethoxazole (9%). Seventy-three percent had inducible clindamycin resistance. Erythromycin-resistant isolates harbored ermC (15/18) and LmrS (3/18) resistance genes. Ciprofloxacin resistance was mediated by mutations of the quinolone resistance-determining region (QRDR) sequence in the gyrA (S84L) and parC (S80Y) genes. All isolates belonged to the CC8 and ST8-SCCmecIV MRSA clone. Ninety-five percent of the MRSA isolates were spa-type t1476, and one exhibited spa-type t064. All isolates were negative for Panton-Valentine leucocidin (PVL) and arginine catabolic mobile element (ACME) type 1. All ST8-SCCmecIV-spa-t1476 MRSA clones from Tanzania were unrelated to the globally successful USA300 clone. Carriage of ST8 MRSA (non-USA300) was common among newly diagnosed HIV-infected adults in Tanzania. Frequent co-resistance to non-beta lactam antibiotics limits therapeutic options when infection occurs.

scholarly journals The prevalence of resistance to macrolides and lincosamides among community- and hospital- acquired staphylococci and streptococci isolates in southeast Serbia

2018 ◽  
Vol 146 (7-8) ◽  
pp. 384-390
Author(s):  
Milena Misic ◽  
Aleksandra Arsovic ◽  
Jelena Cukic ◽  
Milenko Rosic ◽  
Jelena Tosic-Pajic ◽  
...  
Keyword(s):  
Empirical Therapy ◽  
Local Area ◽  
Diffusion Method ◽  
Streptococcal Infections ◽  
Coagulase Negative Staphylococci ◽  
Disk Diffusion Method ◽  
Inducible Clindamycin Resistance ◽  
Drug Of Choice ◽  
One Year ◽  
Hospital Acquired

Introduction/Objective. The increasing resistance to macrolides and lincosamides among staphylococci and streptococci is becoming a global problem. The aim of this study was to investigate the prevalence of macrolide-lincosamide-streptogramin (MLS) resistance phenotypes in staphylococcal and streptococcal isolates in southeast Serbia. Methods. The MLS phenotypes were determined by the double-disk diffusion method in 2,121 inpatient and outpatient staphylococcal and streptococcal isolates collected during a one-year period at the Center for Microbiology. Results. The methicillin-resistant staphylococci isolates were significantly more resistant to penicillin, erythromycin, clindamycin, gentamicin, and ciprofloxacin (100%, 100%, 29.2%, 65.6%, and 53.1%, respectively) than the methicillin-sensitive ones (93.6%, 64.9%, 12%, 28.9%, and 11.7%, respectively). The inducible clindamycin resistance phenotype was dominant in S. aureus and coagulase-negative staphylococci isolates. S. pneumoniae, S. pyogenes, and S. agalactiae isolates showed very high resistance to erythromycin (77.8%, 46.2%, and 32.4%, respectively). All staphylococci and streptococci isolates were sensitive to vancomycin and linezolid, and all beta-hemolytic streptococci isolates to penicillin and ceftriaxone. Conclusion. The phenotypic triage of staphylococci is necessary in order to separate inducible resistant and truly clindamycin-sensitive isolates. Macrolides should not be recommended for empirical therapy of streptococcal infections. Penicillins remain the drug of choice for treatment of streptococcal infections in our local area.

Evaluation of antibiotic resistance pattern and mecA gene frequency in methicillin-resistant Staphylococcus aureus strains collected from clinical specimens in Marand hospital and treatment centers, Iran

2021 ◽  
Author(s):  
Abolfazl Jafari-Sales ◽  
Zahra Sadeghi Deylamdeh ◽  
Afsoon Shariat
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Meca Gene ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Medical Centers ◽  
Wide Range

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods.  Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene.  The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics.  Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.

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.

scholarly journals Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

2020 ◽  
Author(s):  
Joanne Karzis ◽  
Inge-Marié Petzer ◽  
Edward F. Donkin ◽  
Vinny Naidoo ◽  
Eric M. C. Etter
Keyword(s):  
South Africa ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dairy Herds ◽  
Disk Diffusion Method ◽  
Milk Samples ◽  
Kwazulu Natal ◽  
Over Time

Abstract Background The discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories. Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disk diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previous (Intermediate category grouped with Resistant) and current definitions, (Intermediate category grouped with Susceptible). The results of the analysis between the previous and the current definitions differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous nor the current systems showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study, with the lowest prevalence of resistance shown in KwaZulu-Natal during spring. For the susceptibility testing of 57 maltose negative and 57 maltose positive S. aureus isolates from 38 farms, from KwaZulu Natal, Eastern Cape and Western Cape. The minimum inhibitory concentration (MIC) results for the maltose negative S. aureus isolates confirmed the results of the disk diffusion method. Conclusions The maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multidrug -resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

Sign in / Sign up

Export Citation Format

Share Document