ANTIBIOTIC RESISTANCE PATTERN OF ISOLATES FROM WOUND AND SOFT TISSUE INFECTIONS.

Two-hundred and eighty bacterial isolates from wound and soft tissue infections were studied for species identification and antibiotic resistance pattern. Amongst them 122 isolates were from community acquired infection and 158 were from nosocomial infections. The common community acquired pathogens were Staphylococcus aureus (67.8%) and Streptococcus pyogenes (10.7%), whereas Staphylococcus aureus (60.1%) and E. Coli (8.9%) were common in nosocomial infection. Only two anaerobes (Cl perfringens) were isolated. Penicillin resistance was found to be 87% and 92% for Staphylococccus aureus in community acquired and noscomial infections respectively. 85% of Proteus isolates were resistant to ampicillin. There was relatively lower level of resistance by all isolates to cefotaxime. Gentamicin showed higher rate of resistance than netilmicin and amikacin. Resistance of E. coli isolates to fluoroquinolones being 79% for norfloxacin, 81% for ciprofloxacin and 60% for ofloxacin. The study showed a higher resistance of methicillin resistant Staphylococcus aureus (MRSA) to other antibiotics. Amikacin and ofloxacin were the best recommended drugs for empirical therapy for all organisms, the susceptibility rate being 80.7% and 80.4%.

EPIDEMIOLOGICAL STUDY OF ENTEROPATHOGENIC CARRIER STATE AMONG FOOD HANDLERS OF ARMED FORCES EATING ESTABLISHMENTS.

A cross-sectional epidemiological study was undertaken on a randomly selected sample of 308 food handlers working in different eating establishments of Indian Armed Forces in Pune. These included 101 Service personnel and 207 civilians. Stool samples were analysed for enteropathogens and epidemiological assessment of gastrointestinal disease occurrence in the military units of these food handlers was undertaken. The study revealed that 4 of the subjects were carriers of salmonella typhimurium, thus giving the prevalence as 1.3% (95% confidence interval 0.2% to 2.56%). No other enteropathogen except salmonella typhimurium was isolated. The positive carriers showed a typical "spatial - clustering" in that they were working in two geographically contiguous medical units.

CHANGES IN URINARY ISOLATES AND THEIR ANTIBIOTIC RESISTANCE PATTERN.

A total of 338 urinary isolates were studied at AFMC, Pune during 1998 for species identification and antibiotic resistance. Out of 145 community isolates E coli were 67% followed by Staph aureus (11%). The hospital isolates of E coli and Proteus spp showed higher resistance to ampicillin (81% and 89% respectively) than to cefotaxime (23% and 22% respectively). K pneumoniae showed relatively higher resistance to cefotaxime i.e. 54% for community strains and 75% for hospital strains. Proteus spp showed higher resistance to fluoroquinolones i.e. 78% for norfloxacin and 82% for ofloxacin as compared to other coliforms and Pseudomonas aeruginosa. Among aminoglycosides bacterial resistance to amikacin is less than to commonly used netilmicin and gentamicin. Hospital isolates of K pneumoniae are 100% resistant to sulphamethoxazole and to trimethoprim. Susceptibility testing is emphasized as a must both for hospital and community isolates, but when empirical treatment is contemplated for community isolates nitrofurantoin, nalidixic acid, amikacin, cefotaxime, gentamicin and piperacillin are recommended as first line choices and for hospital isolates amikacin, cefotaxime and netilmicin are recommended until susceptibility report is available.

UREAPLASMAS UREALYTICUM AND HUMAN INFERTILITY: EFFECT ON SPERMATOZOA MORPHOLOGY.

Seminal fluids of 197 males with complaints of involuntary infertility were examined for spermatozoal counts, morphological changes in the spermatozoa and cultured for ureaplasmas and mycoplasmas. In 12, no spermatozoa were present, 29 had a count of less than one million and 156 had more than one million spermatozoa per mL of the seminal fluid. Various morphological changes were detected in the spermatozoa in some cases. U urealyticum and M hominis were grown in 43.15% and 16.75% in comparison to control figures of 15.9% and 11.4% respectively. There was no correlation between growth of ureaplasmas and the spermatozoal count. Among the morphological changes, presence of coiled tails, presence of a fuzzy coat around the tail and microcolonies were highly specific for culture positivity (98.2, 98.2 and 97.35% respectively) but of low sensitivity (55.2%, 14.1% and 8.2% respectively).

A STUDY OF METHODS USED FOR DISINFECTION OF ANAESTHETIC EQUIPMENT BETWEEN TWO SURGICAL OPERATIONS AT A LARGE TEACHING HOSPITAL.

A prospective study on the growth of bacteria on certain commonly used anaesthetic equipment was undertaken in a large teaching hospital with a view to assess the effectiveness of disinfection/sterilization procedures. Samples for microbiological assessment were drawn by the worker using standardised procedures and tested in the laboratory by a microbiologist, blinded to the type of sample. Criteria for growth positivity was taken as > 25 colony forming units. A total of 90 observations were taken. 30 each for 'before use', 'after use' and 'after disinfection'. Overall 54.6% of the equipment showed growth "before use" with maximum growth being seen in Suction catheters (66.6%) and Guedal airways (60.0%). On the other hand, the proportion of equipment showing growth "after use" was quite high (84.6%), with suction catheters and endotracheal tubes showing 90.0% growth each. There was significant difference as regards "before" and "after" use growth on Endotracheal tubes, Guedel airways and Face masks (p < 0.05). Analysis of growth "after" disinfection" revealed that the probability of growth remains as high as 70% in suction catheters (95% CI=54% to 86%) and 60% in laryngoscopes (95% CI=43% to 78%). The study revealed gross inadequacies in methods of disinfection being followed at present.

PLASMID MEDIATED DRUG RESISTANCE IN VIBRIO CHOLERAE 0139 BENGAL.

Sixteen strains of Vibrio cholerae were isolated from cases of diarrhoea. Out of these, 12 (75%) were identified as Vibrio cholerae 0139 synonym Bengal and 4 (25%) as Vibrio cholerae El Tor by standard biochemical and serological tests. Modified CAMP reaction in sheep blood agar showed that 0139 produced moderate hemolysis, El Tor produced wider zone of hemolysis whereas Classical Vibrio cholerae produced no zone of hemolysis (CAMP negative). Break point minimum inhibitory concentration (MIC) by agar dilution method showed that all 0139 strains were resistant to ampicillin 8 mg/L, streptomycin 1 mg/L, chloramphenicol 8 mg/L, sulphamethoxazole 32 mg/L and trimethoprim 0.3-128 mg/L, 58.3% were sensitive to gentamicin 1 mg/L, and all were sensitive to norfloxacin 1 mg/L and cefotaxime 1 mg/L. Resistance to trimethoprim, sulphamethoxazole, ampicillin and gentamicin in 5 strains could be transferred to E coli K-12 by conjugation experiment at a rate of 5×10-6 to 4×10-3. Distinct plasmid bands of 35.8 mega daltons could be seen in agarose gel electrophoresis.