Evaluation of a new rapid antibiogram method, the Rapid-ATB system. Comparison with the agar dilution reference method and the standard antibiogram

Results given by Rapid-ATB, a new automated system for the four hour susceptibility testing of bacteria were compared in this study to results given by agar dilution test and disc agar diffusion test. For 100 Enterobacteriaceae strains tested against ten antibiotics, overall agreement between agar dilution test and Rapid-ATB was 99.4%. 6 major discordances concerning especially chloramphenicol were only detected in 1 000 realized susceptibility tests. Overall agreement between agar dilution test and disc agar diffusion test was 96.7%. Eighteen major discordances concerning alike chloramphenicol, but also doxycycline and nalidixic acid, and fifteen minor discordances were detected in this comparison. These results prove the high reliability of this new system which give results more precise than these of disc agar diffusion test.     

Isolation, characterisation and antibiogram of Enterococci from clinical samples

During a one year study 2955 clinical specimens of pus, urine, wound swabs, blood cultures, discharges from fistula, peritoneal aspiration fluid, CSF and sputum were processed to find out the prevalence rate of enterococci. One hundred isolates (3.38%) of Enterococci were obtained which were speciated by conventional methods. The highest incidence was from isolates of urine (43%), pus (40%), wound swabs (11%), and the least incidence was noted in discharges from fistula (2%), blood cultures (2%) and peritoneal aspiration fluid (2%). 98% were Enterococci and among these 88% of the isolates were Enterococcus faecalis. Antibiogram of the isolates were done by Standard disc diffusion method and Vancomycin sensitivity was found to be 95%.     

Changing spectrum of invasive candidiasis and its therapeutic implications

Emerging trends in invasive candidiasis are notable for a dramatic increase in infections due to non-albicans Candida species. An increasing number of immunocompromised patients at risk from fungal infections, an overall greater acuity of illness in the hospitalized patients, particularly those in the critical care units, escalating rates of broad-spectrum antibiotic usage, and wide utilization of azoles as prophylaxis have probably contributed towards the changing epidemiology of invasive candidiasis. Given the inherent decreased susceptibility of many of the non-albicans Candida species to currently available antifungal agents, these evolving trends have far-reaching clinical relevance.     

Bacteriological study of renal calculi

The pre-operative urine, pelvic urine, removed calculi and calculus washings were examined bacteriologically in 24 patients undergoing removal of intrarenal calculi. Four of seven patients with struvite calculi had an infected pre-operative midstream urine specimen and six of the seven removed calculi demonstrated significant bacterial growth.Proteus mirabilis was the commonest organism isolated. Of 17 patients with oxalate calculi only one had an infected pre-operative urine culture, but in four cases the removed stones were infected. Quantitative bacteriological culture of the stones and their washings demonstrated that infection is within the stone itself. Pre-operative urine culture failed to predict infection within the stone in 60 % of patients with infected stones. The results suggest that the presence of infected urine together with the presence of renal calculus is indication for removal of the calculus.     

Bacteriological analysis of burn sepsis

A total of 114 opportunistic bacteria were isolated from 65 swabs from burn sepsis. P. aeruginosa (53.8%) was the most common agent followed by S. aureus (38.4%), Klebsiella Spp. (27.6%), Proteus (18.4%), E. coil (10.7%) and others. The infection was monobacterial in 25 cases (38.4%) and polybacterial in 49 cases (61.5%). P. aeruginosa was predominated in both monobacterial and polybacterial infections. Ciprofloxacin (42.9%) was found to be the most effective antibacterial agent. Results indicate that resistance in burn isolates is higher and increasing day by day.