Serogroup prevalence of Shigellae in Bombay.

Prevalence of Shigellae serotypes in Bombay was studied from June 1988 to May 1991. A total of 2758 faecal specimens were collected from paediatric patients (< 12 yrs) with acute gastroenteritis. A total of 90 Shigella were isolated giving the isolation rate of 3.2%. Shigella flexneri was the predominant serogroup (73.3%) followed by Shigella dysenteriae (16.6%). All the isolates were sensitive to nalidixic acid. Eighty percent of the Shigellae were multidrug resistant. Present data were compared with the study carried out during the period of 1983-87 from the same institute. A change in the serogroup prevalence was noted wherein Shigella flexneri dominated over Shigella dysenteriae since 1985. Increase in resistance to ampicillin and cotrimoxazole was seen in Shigella flexneri strains as compared to previous years.

Detection of Chlamydia trachomatis antigen & Toxoplasma gondii (IgM) & Mycoplasma hominis (IgG) antibodies by ELISA in women with bad obstetric history.

A total of 365 non pregnant women with bad obstetrics history (BOH) were studied with a control group of 100 women who had delivered full term clinically normal infants. The presence of C. trachomatis antigen and T. gondii (IgM) and M. hominis (IgG) antibodies was assessed by ELISA test. C. trachomatis antigen was detected in 28.2 per cent of women with BOH whereas T. gondii and M. hominis specific antibodies were found in 43.83 and 27.1 per cent respectively, these were highly significant (P < 0.001) in comparison with the control group. In case, facilities for culture are not available then detection of antigen and IgM class of antibodies by ELISA can pinpoint current infection.

Microbiological study of mycetoma patients from Bombay with special reference to actinomyces immunofluorescence.

17 of the 21 clinically diagnosed mycetoma and actinomycosis cases studied yielded positive cultures. Foot, leg, inguinal region, chest wall, jaw and scalp were the affected sites. 15 of the patients were from Bombay, 13 of them had infection due to Nocardia species and 2 had Actinomyces israelii infection. The other two patients from South India had Madurella mycetomi infection. N.brasiliensis was commonest isolate (8). Other isolates were N.asteroides (2), N.pelletieri (2), N.caviae (1) and A.israelii (2). A direct fluorescent antibody test to detect actinomyces was used in selected cases (4). Two of whom gave positive immunofluorescence with A.israelii FITC labeled globulin, in primary smears as well as in cultures.

Laboratory data from the surveillance of a burns ward for the detection of hospital infection.

Nosocomial infection is a major problem affecting many hospital personnel and patients. Surveillance of intensive care areas such as burns wards is important due to the immunocompromised status of the patients. Since infection has been found to be a major cause of death in our burns ward, bacteriological surveillance of the area was carried out over a 1-year period. This indicated the various sources of infection, which included a contaminated container of disinfectant, and transient pathogenic flora on one of the staff members involved in changing dressings. Pseudomonas aeruginosa was the most commonly isolated pathogen from infected wounds as well as from the blood of patients developing sepsis. Autogenous spread of this organism was confirmed by similar pyocin typing results of the strains isolated from wounds, blood and faeces of the patients. Necessary changes were implemented based on these findings and the infection rate was reduced remarkably. The results suggested that strict vigilance by the personnel involved in the care of burns patients reduces the incidence of invasive sepsis and shortens the hospital stay.

Mycoplasma hominis in women with bacterial vaginosis.

An association between M. hominis and bacterial vaginosis (BV) was looked for in total 205 women characterized as having BV. Vaginal specimens from these patients were studied for the presence of amines, polymorphonuclear leukocytes, clue cells, and lactobacilli, and were also cultured to isolate Gardnerella vaginalis, M. hominis, Trichomonas vaginalis, Candida albicans and anaerobes. G. vaginalis was found to be the most common isolate from 132 cases (64.3%). M. hominis was isolated from 90 cases (43.9%). 62 per cent of M. hominis isolates were associated with G. vaginalis. 100 age matched control group revealed low prevalence of G. vaginalis and M. hominis whereas the difference in isolation rate of anaerobes was not significant. Anaerobes were found in association with M. hominis in 40 per cent cases. The treatment of these patients was decided after knowing the etiological agent.

Acute Campylobacter jejuni enteritis in 385 hospitalised patients.

Twenty healthy controls and 385 adult patients suffering from acute enteritis or gastroenteritis were enrolled for the study of Campylobacter Jejuni infection over a period of 2 years. Thirty five stool samples showed C jejuni on stool culture. The isolation rates were at peak in the monsoon season and from watery and bloody stool specimens. Pure C jejuni culture was obtained in 18 of 35 samples; the other 17 samples showed polymicrobial infection or infestation. Nine of 35 patients were treated with erythromycin 1 g in divided doses for 7 days. Repeat stool cultures did not grow C jejuni. There was no resistance to erythromycin therapy. C jejuni are fastidious organisms and require special medium and microaerophilic environment for culture.

Aeromonas spp. and their association with human diarrheal disease.

Between January 1988 and December 1989 Aeromonas species were isolated from 45 (1.8%) of 2,480 patients with acute gastroenteritis. No other bacterial enteric pathogens were found in any of these 45 patients. Of the 45 Aeromonas isolates, 35 strains (77.8%) were Aeromonas hydrophila, 7 (15.5%) were Aeromonas sobria, and 3 (6.7%) were Aeromonas caviae. Most of the patients were under 5 years of age. No bacterial enteric pathogens, including Aeromonas species, were isolated from 512 age- and sex-matched control subjects. Examination of the Aeromonas isolates for exotoxin production (enterotoxin and hemolysin) indicated that all strains, irrespective of species, were enterotoxin positive (rabbit ileal loop model) and hemolysin positive (rabbit erythrocyte model). These results suggest that Aeromonas species are potential enteric pathogens in our geographical region.

A study of V. cholerae strains isolated in Bombay.

Of 935 faecal samples studied over a period of one year, V. cholerae 01 was isolated from 102 samples (10.9%). All the strains were found to be E1 Tor Ogawa. The strains belonging to the phage types 2 and 4 were encountered in our study, type 2 being the highest (76.5%). The sensitivity pattern of all strains to the commonly used antibiotics was determined. Strains sensitive to gentamicin (92.2%), nalidixic acid (85.3%), kanamycin (83.3%), cotrimoxazole (80.4%) and chloramphenicol (75.5%) were observed. Out of the total, 36.3%, 29.4% and 28.4% of V. cholerae strains were found to be resistant to ampicillin, streptomycin and tetracycline respectively. V. cholerae was isolated throughout the year indicating the endemicity of cholera in Bombay.

Biotypes of Gardnerella vaginalis isolated from non-specific vaginitis patients in Bombay.

The incidence and prevalent biotypes of G. vaginalis in patients with non-specific vaginitis from Bombay, was studied. Of 300 patients screened, 105 were diagnosed to have nonspecific vaginitis (NSV). G. vaginalis was isolated from 71 per cent patients with NSV; 34.6 and 29.3 per cent G. vaginalis were belonging to biotypes 5 and 1 respectively. In 55 per cent patient, G. vaginalis was associated with anaerobes. None of the isolated strains of G. vaginalis was sensitive to 5 micrograms metronidazole disc whereas 93 per cent of the strains were sensitive to 50 micrograms metronidazole disc.