A Study to Detect Inducible Clindamycin Resistance among Staphylococcus Aureus Isolates and Explore Its Relationship with Methicillin Resistance in a Tertiary Care Hospital of West Bengal (original) (raw)
Related papers
Journal of Pharmaceutical & Scientific Innovation, 2015
MRSA has been considered a major nosocomial pathogen in healthcare facilities but recently it has been observed emerging in the community as well. Clindamycin is a preferred therapeutic option in the treatment of both methicillin susceptible and resistant staphylococcal infections. The present study was aimed to determine the incidence of constitutive and inducible clindamycin resistance among Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and Hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) isolates. A 600 staphylococcal strains were isolated from various clinical specimens. Antibiotic susceptibility tests were performed using standard method. Methicillin resistance was detected by cefoxitin (30 ug) disc diffusion test using Mueller-Hinton Agar. D-test was performed on all erythromycin resistant and clindamycin sensitive isolates to detect inducible clindamycin resistance. MRSA was documented in 28 % amongst 600 isolates of S. aureus. Out of these 64.66 % and 35.33 % isolates of S. aureus were hospital associated and community associated respectively. Among these, 216 S. aureus were resistant to Erythromycin, 61 isolates were MRSA. Out of these 42 (68.85 %) were HA-MRSA and 19 (31.14) were CA-MRSA. We observed 3 (15.78 %), 16 (84.21 %), 0 % were iMLSB, MS phenotype and cMLSB in CA-MRSA respectively. 18 (42.85 %) iMLSB, 21 (50 %) MS phenotype and 3 (7.14 %) cMLSB observed in HA-MRSA. Our study suggested that MLSB resistance in S. aureus should be under constant surveillance in every country and region. The D-test for detection of iMLSB resistance should be carried out routinely in laboratories so as to prevent therapeutic failures.
IOSR Journal of Pharmacy and Biological Sciences, 2013
Clindamycin is an alternative choice for mild to moderate MRSA infections especially in penicillin-allergic patients. Clindamycin has been used to treat serious infections caused by susceptible Staphylococcus aureus strains in children for more than 30 years. It remains effective for many infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). The clinical implications of a positive D-test begin with an understanding of cross resistance for 3 antibiotic families that share a common binding site-macrolides (e.g., Erythromycin) Lincosamide (e.g.; Clindamycin), and group B streptogrammins. A positive D-test indicates the presence of MLSBi genotype. However, sub inhibitory concentration of Erythromycin is a common inducer of Inducible Clindamycin resistance (ICR). When Erythromycin diffuses, it induces, resistance to Clindamycin and results in flattening of the Clindamycin zone of inhibition just next to the Erythromycin disk, making a D shape, so this method is called D-test. Susceptibility testing was performed according to BSAC (British society for antimicrobial chemotherapy) on isolates of Staphylococcus aureus by using the method of disk diffusion. All MRSA isolates processed were found to have positive D Test. Staphylococcus aureus is one of the most common human pathogens with ability to cause wide range of infections.
The Professional Medical Journal
Objectives: D-Test as a tool to detect the frequency of clindamycin resistance in community acquired and hospital acquired methicillin resistant Staphylococcus aureus infections. Study Design: A cross-sectional study. Setting: Microbiology department of BMSI, JPMC, Karachi. Period: January 2015 till December 2015. Material & Methods: Pus samples from deep wounds, skin lesions, abscesses, postoperative wounds from surgical, medical wards and OPDs were collected. MRSA testing and susceptibility testing for antibiotics was done according to CLSI2014. The frequency of inducible clindamycin resistance was detected by D-Test of the CA-MRSA and HA-MRSA. Result: In a total of 402 S. aurous isolates, 253 (62.93%) were methicillin-sensitive and 149 (37.06%) were methicillin-resistant. Out of 149 MRSA, 106 (71.14%) were HA-MRSA and 43(28.85%) were CA-MRSA. Among the HA-MRSA, 63(59.8%) were resistant to clindamycin while with D-Test, it increased to 78(73.58%). Out of 43 CA-MRSA, 9 (21.6%) were...
International journal of endorsing health science research, 2024
Background: Staphylococcus aureus is a prevalent pathogen causing both nosocomial and communityacquired infections worldwide. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) due to the acquisition of mecA and mecC genes poses a significant clinical challenge. The injudicious use of clindamycin for treating MRSA has led to the development of clindamycin resistance. This study aimed to determine the prevalence of inducible clindamycin resistance (iMLSB resistance phenotype) in Staphylococcus aureus isolates, employing the D test according to CLSI guidelines, particularly focusing on erythromycin-resistant strains. Methodology: A total of 147 Staphylococcus aureus isolates were subjected to antibiotic susceptibility testing using the Kirby Bauer disc diffusion method. The D test was employed to identify inducible clindamycin resistance. Results: The study revealed that 34% of isolates exhibited inducible clindamycin resistance, 40% demonstrated constitutive resistance, and the remaining 26% exhibited the MS phenotype. Notably, inducible clindamycin resistance was more prevalent in MRSA (40%) compared to MSSA (22%). Conclusion: The findings underscore the importance of incorporating the D test as a mandatory procedure in standard disc diffusion testing to accurately identify inducible clindamycin resistance. This knowledge is crucial for guiding appropriate antibiotic therapy in the face of increasing resistance patterns.
Now a days clinicians switch over to drug Clindamycin to treat Staphylococcus aureus infections. Clindamycin is belonging to lincosamide group. As frequent use of this Clindamycin develops resistance among patients and ultimately treatment failure. Aim: This present research is done to identify type of resistance like inducible or constitutive macrolide lincosamide-streptogramin B (iMLSB /cMLSB) resistance and MS (Macrolide lincosamide streptogramin) phenotypes among Staphylococcus aureus isolated from various samples received in Microbiology laboratory of tertiary care hospital of south Gujarat. Materials and Methods: Among various samples total 232 Staphylococcus aureus were isolated. And all these isolates were subjected to routine antibiotic sensitivity testing by kirbey bauer disc diffusion method. Methicillin resistance staphylococcus aureus (MRSA) detected by using Cefoxitin disc. D test is performed as per Clinical and laboratory standards institute (CLSI) guidelines on all isolates. Results: Total of 232 Staphylococcus aureus were isolated, among them 109 were Methicillin sensitive Staphylococcus aureus (MSSA) and 123 were Methicillin resistant Staphylococcus aureus (MRSA). Prevalence of iMLSB, cMLSB and MS phenotype were 59.34% ,15.44% and 13% in MRSA while 12.84%, 14.67% and 22.93% respectively in MSSA. Conclusion: This research helps to detect Clindamycin resistance among Staphylococcus aureus and role of D test before starting the treatment with Clindamycin. By these knowledge clinician can choose correct treatment and we can prevent a treatment failure.
INDUCIBLE CLINDAMYCIN RESISTANCE AMONG CLINICAL ISOLATES OF STAPHYLOCOCCUS AUREUS
National Journal of Medical Research, 2015
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 (MLSB) antibiotics to treat Staphylococcus aureus infections. Clinical failure has been reported due to multiple mechanisms that confer resistance to MLSB antibiotics. Aims: The present study was aimed to detect inducible clindamycin resistance among S. aureus isolates and to study the relationship between clindamycin and methicillin resistance. Materials and Methods: During a period of 6 months, a total 297 S. aureus isolates from various clinical specimens were included in the study. Antimicrobial susceptibility test was done by Kirby-Bauer’s disc diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines. For detection of inducible clindamycin resistance, D test using erythromycin and clindamycin as per CLSI guidelines was performed, and three different phenotypes were interpreted as MS phenotype (D test negative), inducible MLSB (iMLSB) phenotype (D test positive), and constitutive MLSB phenotype. Results: Of the total 297 S. aureus isolates, majority were obtained from pus 35% (104), from swab 52% (153) followed by blood, tissue samples and body fluids 13% (40). Out of 297, 71% (211) were erythromycin resistant. Out of the total 297 isolates, 30.30% (90) were methicillin-resistant S. aureus (MRSA) and 69.69% (207) were methicillin-sensitive S. aureus (MSSA). MLSB phenotype in 13.46%, MS phenotype in 32.65%, and constitutive MLSB phenotype was observed in 24.91% of isolates. Inducible clindamycin resistance was more among MRSA than MSSA isolates. Conclusion: D test should be included as a mandatory method in routine disc diffusion testing to detect inducible clindamycin resistance in staphylococci for the optimum treatment of patients.
Introduction: Clindamycin is an excellent drug for skin and soft tissue Staphylococcus aureus infections, but resistance mediated by inducible macrolide-lincosamide-streptogramin B (iMLS B ) phenotype leads to in vivo therapeutic failure even though they may be in vitro susceptible in Kirby-Bauer disk diffusion method. Objective: The study was aimed to detect the prevalence of iMLS B phenotype among S. aureus isolates by double disk approximation test (D-test) in a tertiary care hospital, Eastern India. Materials and Methods: A total of 209 consecutive S. aureus isolates were identified by conventional methods and subjected to antimicrobial susceptibility testing by Kirby-Bauer disk diffusion method. Erythromycin-resistant isolates were tested for D-test. Results: From 1282 clinical specimens, 209 nonrepeated S. aureus isolates were obtained. Majority of isolates 129 (61.7%) were methicillin-resistant S. aureus (MRSA). There was statistically significant difference between outpatients 60.1% and inpatients 39.9% (P < 0.0001). From 209 S. aureus isolates, 46 (22%) were D-test positive (iMLS B phenotype), 41 (19.6%) were D-test negative (methicillin sensitive [MS] phenotype), and 37 (17.7%) were constitutively resistant (constitutive macrolide-lincosamide-streptogramin B phenotype). The incidence of inducible, constitutive, and MS phenotype was higher in MRSA isolates compared to MS S. aureus (MSSA). The constitutive clindamycin resistance difference between MSSA and MRSA isolates were found to be statistically significant (P = 0.0086). Conclusion: The study revealed 22% of S. aureus isolates were inducible clindamycin resistant, which could be easily misidentified as clindamycin susceptible in Kirby-Bauer disk diffusion method. Therefore, clinical microbiology laboratory should routinely perform D-test in all clinically isolated S. aureus to guide clinicians for the appropriate use of clindamycin.
Journal of Evolution of Medical and Dental Sciences
Methicillin resistant Staphylococcus aureus has become endemic in India with the prevalence ranging from 25% in the west India to 50% in south India. Clindamycin therapy is a useful alternative to treatment of such infections. However, bacterial resistance to this drug has been known to occur through various mechanisms with variable prevalence in different geographical regions and among Methicillin Sensitive (MSSA) and Methicillin Resistant Staphylococcus aureus (MRSA). The most common being MLSB (Macrolide, Lincosamide and Streptogramin B) resistance mediated by erm genes. While constitutive MLSB resistance is easily picked up by routine antimicrobial disc diffusion susceptibility tests, the inducible MLSB resistance is only picked u p by D zone test. MATERIAL AND METHODS We evaluated 343 clinical isolates of Staphylococcus aureus for MLSB resistance phenotypes using D zone test. Identification of Staphylococcus aureus isolates was done by standard biochemical techniques and then subjected to routine susceptibility testing by Kirby Bauer's disc diffusion method on Mueller Hinton agar plates. RESULTS All isolates were resistant to penicillin. 61.23% (210) were MRSA and 38.77% (133) were MSSA. Among the MRSA isolates 49.5% and 7.14% isolates showed cMLSB and iMLSB resistance respectively, whereas among 133 MSSA isolates 8.27% and 2.26% isolates showed cMLSB and iMLSB resistance respectively. DISCUSSION The present study revealed a high prevalence of cMLSB in our region. Also prevalence of cMLSB and iMLSB resistance in MRSA is higher than that in the MSSA isolates showing that the distribution of MLSB resistance phenotypes varies among MSSA/MRSA isolates and among different geographical regions. Overall, we found 43.33% clindamycin resistance among MRSA and 10.5% resistance among MSSA isolates. We suggest clindamycin should be used as a therapeutic drug with caution for Staphylococcal infections and recommend that the D zone test should be used as a routine screening procedure to evaluate inducible clindamycin resistance in Staphylococcus aureus to overcome any subsequent treatment failure.
2015
Staphylococcus aureus (S. aureus) has been continuously acquiring resistance to many antibiotics at an alarming speed. Penicillin resistance was first noticed in 1944 and methicillin resistance was first observed in 1961 [1]. Recent emergence of inducible clindamycin resistant S. aureus, has further limited our choice of antibiotics. This study was undertaken to find out the prevalence of inducible (iMLS B) and constitutive clindamycin resistance (cMLS B) among the clinical isolates of S. aureus. A total of 100 non-duplicate clinical isolates of S. aureus were collected from June 2014 to March 2015. D-test was performed in routine by placing clindamycin (CLI) disc 2μg and erythromycin (ERY) disc 15μg approximately 15-26 mm apart measured edge to edge on a Muller-Hinton agar plate that has been inoculated with a Staphylococcus isolate incubated at 35±2°C in ambient air. In this study, 92 (92%) of S. aureus isolates were found to be methicillin resistant (MRSA) and 8 (8%) tested sensitive to cefoxitin, i.e., methicillin sensitive S. aureus (MSSA). Among 92 strains of MRSA, a total of 36(39.1%) exhibited iMLS B resistance, 16 (17.40%) were positive for constitutive macrolide, lincosamide and streptogramin B resistance (cMLS B) phenotype and 8 (8.70%) belonged to macrolide and streptogramin (MS) phenotype. Among 8 isolates of MSSA, only 2 (25%) strains were found positive for iMLS B resistance and rest 6 strains were sensitive to clindamycin. D-test should be performed routinely on all isolates of S. aureus in order to check iMLS B resistance.
BMC Infectious Diseases, 2017
Background: Staphylococcus aureus, an important nosocomial pathogen, is frequently associated with infections in human. The management of the infections by it especially methicillin resistant ones is often difficult because methicillin resistant S. aureus is usually resistant to multiple antibiotics. Macrolide-lincosamide streptogramin B family of antibiotics is commonly used to treat such infections as an alternative to vancomycin. Methods: This study was conducted over the period of one and half year from November 2013-April 2015 in Microbiology laboratory of Nepal Medical College and Teaching Hospital, Kathmandu, Nepal to find the incidence of different phenotypes of MLS B resistance among S. aureus from clinical samples and their association with methicillin resistance. Two hundred seventy isolates of S. aureus were included in the study. Methicillin resistance was detected by cefoxitin disc diffusion method and inducible clindamycin resistance by erythromycin and clindamycin disc approximation test (D-test). Results: Of the 270 clinical isolates of S. aureus, 25.1% (68/270) were MRSA. Erythromycin and clindamycin resistance was seen in 54.4% (147/270) and 41.8% (113/270) isolates respectively. Resistance to erythromycin and clindamycin were higher in MRSA as compared to MSSA (erythromycin-resistance: 88.2% Vs 39.1% and clindamycinresistance: 79.4% Vs 41.8%). The overall prevalence of i MLS B and c MLS B phenotype was 11.48% (31/270) and 29.25% (79/270) respectively. Both i MLS B and c MLS B phenotypes predominated in MRSA strains. Conclusions: Detection rate of MRSA in our study shows the necessity to improve in healthcare practices and to formulate new policy for the control of MRSA infections. Clindamycin resistance in the form of i MLS B and c MLS B especially among MRSA emphasizes the need of D-test to be performed routinely in our set up while using clindamycin as an alternative choice to anti-staphylococcal antibiotics like vancomycin and linezolid in the treatment of staphylococcal infections.