Different Antibiotic Resistance And Of Resistance Gene Among β-hemolytic Streptococci From Anhui Area

ObjectiveTo analyze clinical distribution characteristics and drug resistance of collected in 2005-2013 β-hemolytic streptococci from Anhui area.To investigate the erythromycin resistant and macrolide resistance gene among 61 clinical β-hemolytic streptococci isolates.MethodsFor all isolates, minimum inhibitory concentrations (MICs) were determined against Erythromycin (ERY), azithromycin (AZM), clindamycin (CIL), penicillin (PEN), ampicillin (AMP), cefepime (FEP), ceftriaxone (CRO), meropenem (MEM), vancomycin (VAN) levofloxacin (LVX), tetracycline (TE), by use of the the Mueller-Hinton agar supplemented with 5% sheep blood dilution method. The results were judged according to the criteria recommended by Clinical and Laboratory Standards Institute (CLSI) 2013. Using WHONET5.4 for analyzing data. PCR method was used to test drug-resistant genes.ResultsThe stains of β-hemolytic streptococci mainly comed from secreta,sputum and swab specimens, accounting for 72.13%. The infection mainly occurred at department of gynaecology and obstetrics; Most patients were old people, the proportion of patients over 60 years old was 60.7%. The stains included A, B, C and G 4 group β-hemolytic streptococcus. The number of strains in each group were 13 (21.3%),42 (68.8%), a (1.6%),5 (8.3%)The results showed that β-hemolytic streptococci was highly sensitive to penicillin and vancomycin. On the contrary, it had a high resistance rate to erythromycin, azithromycin, clindamycin and tetracycline. Resistance rates were 81.97%,80.33%,70.49%,78.69% respectively.Among 13 GAS, resistant gene was mainly ermC genes (76.9%), followed by ermB (46.1%), In 42 strains of GBS, the lowest resistant genes was mphA (4.76%), the detection rate of ermB, ermC, mefA/E, ereB genes was 45.2%,66.7%,45.2% and 66.7%, respectively. 10 strains of GAS, which was resistant to erythromycin, and mediated by ermC (80%), followed by ermB. GCS was resistance to erythromycin and mediated by ermB. Erythromycin resistance was 60% in GGS. The ermB(60%) and ermC(60%) genes were the most prevalent macrolide resistance determinant in GGSConclusionsThe rate of erythromycin of BHS is relatively higher in Anhui Province. Clinicians should enhance the detection of clinical resistance and a reasonable choice of antibiotics need to be made that based on surveillance the results of susceptibility test.