ABSTRACT
Background & objectives: Group C and group G streptococci (together GCGS) are often regarded as commensal bacteria and their role in streptococcal disease burden is under-recognized. While reports of recovery of GCGS from normally sterile body sites are increasing, their resistance to macrolides, fluoroquinolone further warrants all invasive β haemolytic streptococci to be identified to the species level and accurately tested for antimicrobial susceptibility. This study was aimed to determine the prevalence, clinical profile, antimicrobial susceptibility and streptococcal pyrogenic exotoxin gene profile (speA, speB, speC, speF, smeZ, speI, speM, speG, speH and ssa) of GCGS obtained over a period of two years at a tertiary care centre from north India. Methods: The clinical samples were processed as per standard microbiological techniques. β-haemolytic streptococci (BHS) were characterized and grouped. Antimicrobial susceptibility of GCGS was performed using disk diffusion method. All GCGS were characterized for the presence of streptococcal pyrogenic exotoxins (spe) and spe genes were amplified by PCR method. Results: GCGS (23 GGS, 2GCS) comprised 16 per cent of β haemolytic streptococci (25/142 βHS, 16%) isolated over the study period. Of the 25 GCGS, 22 (88%) were recovered from pus, two (8%) from respiratory tract, whereas one isolate was recovered from blood of a fatal case of septicaemia. Of the total 23 GGS isolates, 18 (78%) were identified as Streptococcus dysgalactiae subsp equisimilis (SDSE, large-colony phenotype), five (21%) were Streptococcus anginosus group (SAG, small-colony phenotype). The two GCS were identified as SDSE. All GCGS isolates were susceptible to penicillin, vancomycin, and linezolid. Tetracycline resistance was noted in 50 per cent of SDSE isolates. The rates of macrolide and fluoroquinolone resistance in SDSE were low. Twelve of the 20 SDSE isolates were positive for one or more spe genes, with five of the SDSE isolates simultaneously carrying speA+ speB+ smeZ+ speF or speB+ smeZ+speF, speI+speM+speG+speH or, speI+spe M+speH or speA+ speB+ speC+ smeZ+ speF. One notable finding was the presence of spe B in four of the five isolates of the Streptococcus anginosus group. No isolate was positive for ssa. Interpretation & conclusions: Our study showed no association between GCGS isolates harbouring streptococcal pyrogenic exotoxins and disease severity. This might be attributed to the small sample size of spe-positive isolates.
ABSTRACT
Background & objectives: Perioperative antimicrobial prophylaxis constitutes the bulk of antimicrobial consumption in any hospital. This study was conducted at a level 1 Trauma Centre of a tertiary care hospital of India to assess the efficacy of a short (24 h) course of perioperative antibiotic prophylactic regimen in preventing surgical site infections (SSI) in open reduction and internal fixation (ORIF) of closed fractures of limbs and to assess if the same can be implemented as a general policy. Methods: Patients of either sex, aged 18 yr or more, who were scheduled for ORIF and were willing and able to give informed consent, were included in the study. Patients were randomly allocated into two groups. Group 1 (n=100) received 3 doses of 1 g i.v. cefuroxime perioperatively spaced 12 h apart and group 2 (n=97) received the conventional existing regimen [5 days of i.v. antibiotics (cefuroxime 1 g twice daily along with amikacin 15 mg/kg in 2 divided doses), followed by oral cefuroxime, 500 mg twice daily till suture removal]. Results: Of the 197 patients, four patients developed a surgical site infection (three with methicillin resistant Staphylococcus aureus and one Acinetobacter baumanii). Of these, two patients were in group 1 and the remaining two in group 2. These patients were treated with i.v. antibiotics based on the culture and antimicrobial sensitivity reports. The cost of the short course treatment was ` 150 per patient as compared to ` 1,900 per patient for conventional regimen. Interpretation & conclusions: There was no significant difference in rates of SSI among the two groups in our study. Cost evaluation revealed that shorter course was less expensive than conventional long course regimen. Implementation of a short course perioperative regimen will go a long way in reducing antimicrobial resistance, cost and adverse reactions to antimicrobials.