Differentiation of Candida dubliniensis on chrom agar and Pal's agar.

Difference in expression of putative virulence factors and in antifungal susceptibility among different Candida species has raised the need for species-level identification. The close relationship of Candida dubliniensis with C. albicans has led to misidentification of C. dubliniensis isolates as C. albicans. Phenotypic tests include ability to produce chlamydospore on casein agar, colony colour development on differential media CHROM agar Candida medium and ability to form hyphal fringe on Pal's agar, have been used to differentiate these two Candida species. Fifty isolates of Candida species were recovered from various specimens (blood, urine, tissue and respiratory secretions) from diabetic and cancer patients between April and July 2007. The isolates were tested for chlamydospore production on casein agar. These were also streaked simultaneously on CHROM agar, Pal's agar and a combination of CHROM agar supplemented with Pal's agar for identification and differentiation of C. dubliniensis from C. albicans. On CHROM agar, 19 isolates were identified as C. dubliniensis, nine as C. albicans, 10 as C. krusei, nine as C. tropicalis and two as C. glabrata. One was indeterminate and later identified as C. dubliniensis. Out of the 20 C. dubliniensis isolates, 19 isolates exhibited hyphal fringe on Pal's agar. On CHROM agar supplemented with Pal's agar, 16 out of the 19 fringe-positive isolates exhibited fringe surrounding the bluish green-coloured colonies of C. dubliniensis. Additional identification tests like growth at 45 degrees C and ability to reduce 2,3,5-triphenyltetrazolium chloride were time efficient, inexpensive and easy-to-use methods for differentiation of C. dubliniensis and C. albicans isolates. CHROM agar when supplemented with Pal's agar gave definitive identification between C. dubliniensis and C. albicans.

Incidence of carbapenem-resistant Pseudomonas aeruginosa in diabetes and cancer patients.

Two hundred and thirty isolates of Pseudomonas aeruginosa were obtained from samples of patients having diabetes (75%), cancer (20%), and both diabetes and cancer (5%) who were admitted to a tertiary care hospital in Western India from January to December 2006. These isolates were tested for susceptibility to antipseudomonal drugs and considered to be resistant to carbapenem when the zone of inhibition around imipenem and meropenem discs was < or =13 mm. Of these 230 isolates, 26% were found to be carbapenem resistant. The rapid dissemination of carbapenem resistance is worrisome and calls for the implementation of surveillance studies as well as judicious use of antibiotics.

Bacteriological studies of gas gangrene and related infections.

Gas gangrene, a life threatening condition is predominantly caused by Clostridium spp. Over a five year period (1996-2000), 580 wound swabs were processed from patients who had vehicular accidents with crush injury. The specimens were processed for anaerobic and aerobic organisms by standard laboratory techniques. Of the 580 swabs, 55(9.48%) were primary smear positive for spore bearing bacteria, of which 48 grew Clostridium spp. They were the sole anaerobic isolates in 30 patients (62.5%) whereas Clostridium spp. along with nonsporing anaerobes were isolated in 18 patients. Clostridium perfringens was the predominant isolate in 39 out of 48 cases (81.3%). However, 16 wound swabs which were primarily smear negative for spore bearers, grew Bacteriodes fragilis (11) and Fusobacterium species (5). All these 16 patients had foul smelling discharge with crepitation in the tissues. Our study highlights that apart from Clostridium spp., non-clostridial crepitant infections may present as myonecrosis simulating gas gangrene.

Vibrionaceae from cases of acute diarrhoea and their antimicrobial sensitivity pattern - A five year prospective study.

Over a five year period, stool samples were screened for Vibrionaceae from cases of acute diarrhoea, to study their isolation rate and their antimicrobial sensitivity pattern. All the isolates were identified by standard laboratory techniques. A total of 323 species belonging to Vibrionaceae were isolated from 4492 stool samples tested over five year period (1996-2000), giving a positivity rate of 7.2%. Maximum isolation was during the months of May to August (62.5%). Out of 323 isolates, Vibrio spp. comprised 252 and 93.3% of them were Vibrio cholerae O1 biotype El Tor. Aeromonas spp. were isolated from 71 samples and 64.8% of them were A.hydrophila. V.cholerae showed 86.8% sensitivity to amikacin followed by 73.8% to cefotaxime. Tetracycline sensitivity was only 39.6%. Aeromonas spp. also showed maximum sensitivity to amikacin (70.4%). Isolation of Vibrio spp. have increased over the years, whereas Aeromonas spp. have decreased. Amikacin sensitivity has remained within 70-80% over the years, cefotaxime sensitivity has increased and tetracycline sensitivity has decreased.

An outbreak of leptospirosis in Mumbai.

Following prolonged water logging due to heavy rainfall in Mumbai during July 2000, a total of 102 patients clinically suspected of leptospirosis were admitted in our hospital. Blood samples were examined for the presence of leptospires by dark ground microscopy (DGM) and IgM antibodies were detected by ELISA. Out of 102 blood samples, 37 were positive by ELISA giving a positivity rate of 36.27%. Of these, only 24 were positive by DGM. Out of the positive cases, 37.83% had respiratory symptoms, 32.43% each had jaundice and conjunctival suffusion and 16.21% had renal involvement. Mortality amongst the positive cases was 10.81%. Apart from hepatic and renal involvement, respiratory symptoms due to leptospirosis are on the rise.

Helicobacter pylori in duodenal ulcer disease and its eradication.

Antral biopsy specimens were processed for Helicobacter pylori by Gram staining, rapid urease test (RUT) and culture from 25 patients with symptoms of duodenal ulcer, amongst whom the positivity rate was 84%. Follow up of 16 patients after appropriate therapy showed complete regression of the disease in 87.5% of cases whereas in 12.5% of cases a decrease in the extent of duodenal ulceration was noted.

Anaerobes in pleuropulmonary infections.

A total of 76 anaerobes and 122 aerobes were isolated from 100 patients with pleuropulmonary infections, e.g. empyema (64), pleural effusion (19) and lung abscess (13). In 14% of the patients, only anaerobes were recovered, while a mixture of aerobes and anaerobes was encountered in 58%. From all cases of lung abscess, anaerobic bacteria were isolated, alone (04) or along with aerobic bacteria (13). From empyema and pleural effusion cases, 65.6% and 68.4% anaerobes were recovered respectively. Amongst anaerobes, gram negative anaerobic bacilli predominated (Prevotella melaninogenicus 16, Fusobacterium spp. 10, Bacteroides spp. 9), followed by gram positive anaerobic cocci (Peptostreptococcus spp. 31). Coliform bacteria (45) and Pseudomonas aeruginosa (42) were the predominant aerobic isolates.

Rhinocerebral mucormycosis in a pregnant woman with diabetic ketoacidosis.

Rhinocerebral mucormycosis (RCM) is a rare but often fatal condition characterized by aggressive necrotizing infection originating from nose and spreading to paranasal sinuses, orbit and central nervous system. Although Fungi and spores of mucorales show minimal intrinsic pathogenicity towards normal persons, they can initiate fulminant infections in patients with underlying debilitating conditions. A case of RCM in a pregnant woman with diabetic keto-acidosis successfully treated by supportive care, amphotericin B and surgery is reported.

Aeromonas species isolated from cases of acute gastroenteritis.

A total of 67 Aeromonas strains were isolated as the sole bacterial pathogen from1485 patients with acute gastroenteritis. A. hydrophila (64.2%) was the predominant isolate followed by A. sobria (28.4%) and A.caviae (7.4%). Majority of the isolates were sensitive to gentamicin, nalidixic acid but were resistant to ampicillin. Minimum inhibitory concentration (MIC) of resistant strains of Aeromonas to ampicillin ranged from 80-1280 microg/mL.

Salmonella enteritidis meningitis - A case report.

A male infant admitted with pyogenic meningitis with protein energy malnutrition developed fatal infection due to Salmonella enteritidis. The same organism was isolated from CSF and blood cultures.

Drug resistance to the first line of antitubercular regimen (a preliminary report).

Sputum samples from 100 patients of pulmonary tuberculosis were processed. These patients were admitted in group of Tuberculosis Hospital at Sewri, Mumbai, which is a referral tuberculosis hospital. Isolates were identified as M. Tuberculosis by biochemical tests. Antitubercular sensitivity testing for Isoniazid, Rifampicin, Ethambutol and Streptomycin was performed by resistance ratio method. Total resistance was 36% in our study. Resistance to Isoniazid was 61%: to Rifampicin was 50%, to Ethambutol was 8% and to Streptomycin was 41%. Primary drug resistance to Isoniazid was 45% to Rifampicin was 27%, to Ethambutol was 9%, and to Streptomycin was 54%. Secondary drug resistance to Isoniazid was 68% to Rifampicin was 60%, to Ethambutol was 8% and to Streptomycin was 36%. Secondary drug resistance to Isoniazid and Rifampicin is rising as compared to primary drug resistance to Isoniazid and Rifampicin. This is statistically significant (p < 0.001). 11 out of 36 cases (30%) showed multi drug resistance to Isoniazid and Rifampicin.