Antimicrobial resistance in beta-haemolytic streptococci in India: A four-year study

作者：Bhardwaj Nidhi; Mathur Purva^*; Behera Bijayini; Mathur Kushal; Kapil Arti; Misra Mahesh C

来源：Indian Journal of Medical Research, 2018, 147(1): 81-87.

DOI：10.4103/ijmr.IJMR_1517_16

• Antimicrobial resistance
• beta-haemolytic streptococci
• Group A streptococci
• Group C streptococci
• Group G streptococci

Background & objectives: The incidence and severity of invasive and non-invasive infections demonstrate variability over time. The emerging resistance of Group A streptococci (GAS) to commonly used antibiotics is of grave concern. This study was conducted to assess the antimicrobial resistance of beta-haemolytic streptococci (beta HS) in India and to ascertain the molecular mechanisms of resistance.
Methods: All isolates of beta HS from the Trauma Centre of All India Institute of Medical Sciences (AIIMS) (north India), and heavily populated area of old Delhi from 2010 to 2014 and Yashoda Hospital, Secunderabad (in south India, 2010-2012) and preserved isolates of beta HS at AIIMS (2005-2009) were included. Phenotypic confirmation was done using conventional methods and the Vitek 2. Antibiotic sensitivity testing was done by disc diffusion and E-test. Detection of resistance genes, erm(A), erm(B), mef(A), tet(M) and tet(O), was done by polymerase chain reaction (PCR).
Results: A total of 296 isolates of beta HS (240 from north and 21 from south India) were included in the study. Of the 296 beta HS, 220 (74%) were GAS, 52 (17.5%) were Group G streptococci and 11 (3.7%), 10 (3.3%) and three (1%) were Group B streptococci, Group C streptococci and Group F streptococci, respectively. A total of 102 (46%) and 174 (79%) isolates were resistant to tetracycline and erythromycin, respectively; a lower resistance to ciprofloxacin (21, 9.5%) was observed. A total of 42 (14%) and 30 (10%) isolates, respectively, were positive for tet(M) and erm(B) genes. Only 13 (5%) isolates were positive for mef(A). None of the isolates were positive for erm(A) and tet(O). There was discordance between the results of E-test and PCR for erythromycin and tetracycline.
Interpretation & conclusions: A high level of resistance to erythromycin and tetracycline was seen in beta HS in India. Discordance between genotypic and phenotypic results was reported. Absence of erm(A) and tet(O) with high prevalence of tet(M) and erm(B) was observed.

• 出版日期2018-1
• 单位河北医科大学