جستجوی مقالات مرتبط با کلیدواژه « inducible clindamycin resistance » در نشریات گروه « پزشکی »

We carried out a descriptive study to determine the extent of nasal colonization and characteristics of Staphylococcus aureus and CA-MRSA isolates in 2-5 year old children of day care centers in Isfahan. The characteristics of isolates were determined using standard phenotypic profiles including colony morphology, Gram staining, catalase, hyaluronidase, coagulase and Dnase tests as well as mannitol fermentation. The MRSA detection was carried out according to CLSI guidelines with oxacillin agar screen test. Methicillin resistance was further confirmed by detection of a 310 bp fragment of mecA gene of MRSA by PCR. Drug susceptibility testing to antibiotics other than methicillin was conducted by disk diffusion. The Beta-lactamase production and inducible clindamycin resistance were also determined by performing the double-disc diffusion and D-test. Out of 323 children, 115 (35.6%) carried S. aureus and 11 (9.5%) carried MRSA. All MRSA strains were found to contain mecA gene. The susceptibility of strains to vancomycin, rifampicin and Linezolid were 100%. The susceptibility of strains to gentamicin, clindamycin, erythromycin, co-trimoxazole, amoxiclav, ciprofloxacin, tetracycline and penicillin were 99%, 97%, 94%, 94%, 93%, 88%, 44.4% and 1.8% respectively. Beta-lactamase production was seen in 19 (16.5%) of staphylococcal strains. Inducible clindamycin resistance was seen in 4 (3.5%) of the isolates. Our data indicates that the spread of CA-MRSA within Iranian population is worthy of consideration and merits further molecular investigation to determine the source and mode of transmission.

Increasing frequency of Staphylococcus aureus infections and changes in antimicrobial resistance pattern have led to renewed interest in the use of lincosamide– streptogramin B (MLSB) antibiotics for treatment of infections. Since no study has focused on the molecular epidemiology of community -acquired staphylococcus aureus isolates in Iran، the aim of this study was to determine the molecular typing and prevalence of the macrolides-lincosamides-streptogramins B (MLSB) resistance in community associated s. aureus isolated from healthy students at Arak university of Medical sciences. 568 healthy students from Arak university of Medical sciences were subjected to this study. All samples were subjected to S. aureus–specific isolation procedures. D test was performed to determine various phenotypes as well as spa typing done for molecular typing of these strains. Of 568 the 84 community acquired Staphylococcus aureus، six (7%) were Methiclicin resistant Staphylococcus aureus (CA-MRSA) and 78 (93%) were Methicillin sensitive Staphylococcus aureus (CA-MSSA) of the 84 s. aureus strains، eight (9. 5%) showed constitutive resistance with spa type t660، t701، t304، t5598، t012، t3204، t084 and t1944. Two strains (2. 5%) demonstrated inducible resistance with spa type t9024، t077، two strains (2. 5%) were D test negative with spa type t084 and t1149. 72 (85. 5%) strains. Illustrated susceptible Phenotype. Among CA-MRSA isolates، two strains had constitutive resistance and four remaining CA-MRSA had susceptible phenotype The result of this study indicates that in community associated s. aureus strains، constitutive MLSB resistance rate is higher than the rate of inducible resistance. Presence of inducible resistance to clindamycin in CA-MRSA strains، warrants that D test should be performed to detect this type of resistance. All isolates with inducible and constitutive resistance and D zone negative strains had different molecular typings.

Introduction& The increasing incidence of infections caused by strains of Staphylococcus aureus، especially methicillin-resistant (MRSA)، the use of effective antibiotics such as clindamycin and erythromycin has increased for treatment of systemic and local infections caused by this organism. However، concern over the possibility of emergence of clindamycin resistance during therapy has discouraged some clinicians from prescribing that agent. The aim of this study was to identify the induced clindamycin resistance in clinical isolates of methicillin-resistant Staphylococcus aureus. In this cross-sectional study 100 S. aureus strains isolated from clinical specimens were collected from laboratories of Shiraze (Shahid Faghihi، Namazi and MRI) hospitals. Re-identification of isolates was performed by conventional microbiological and biochemical testes. Methicillin resistant strains were selected by disc diffusion method and inducible clindamycin resistances in these strains were identified with D-zone Test. The susceptibility testing result showed that 44 isolates (44%) of 100 Staphylococcus aureus samples، were resistant to methicillin. Forty-six percent of isolates were resistant to erythromycin and 51% were resistant to clindamycin. Ten isolates (10%) were as induced clindamycin resistances based on D-zone test (8 isolates D phenotype، 2 isolates D+ phenotype)، in those 8 isolates were MRSA and 2 isolates were MSSA. The results showed that performance of D-zone test in clinical laboratories for identification of induced clindamycin resistance and the report of results to the physician for prescribing of these two antibiotics for treatment of infections caused by inducible clindamycin resistance strains and replace with the appropriate treatment regimen is very important.