Rhinosporidiosis and its causative pathogen Rhinosporidium seeberi have been known for over a hundred years. Yet unresolved enigmas in rhinosporidiosis include the mode of infection, mechanisms of spread, mechanisms of immunity, some aspects of histopathology e.g. the significance of transepidermal elimination of sporangia, the cause of the variation in cell infiltration patterns in rhinosporidial tissues and their correlations with immune status, and the absence of the Splendore-Hoeppli reaction which is well-marked in invasive, classical mycoses. This review describes the main features of rhinosporidiosis and discusses recent work which clarifies some of these enigmas. Recent work included in this review are molecular biological classification of R.seeberi among the hydrophilic organisms of the former DRIP clade, establishment of a method for the purification of the developmental stages, and some aspects of the immunology of R.seeberi with reference to mechanisms of immune evasion - antigenic variation, host immunoglobulin binding, immune deviation in relation to the chronicity, recurrence and dissemination seen in rhinosporidiosis. The mechanism of endospore release from the sporangium has been described. Some problems involved in the resolution of enigmas that persist are briefly discussed.

PURPOSE: To highlight the usefulness of polymerase chain reaction (PCR) for the rapid diagnosis of systemic fungal infections. METHODS: Clinical samples were collected from 50 clinically suspected cases of systemic mycosis and subjected to smear, culture, antifungal sensitivity and PCR (based on 18S rRNA gene). RESULTS: Of the 50 clinical specimens tested by PCR, 39 were found to be positive. PCR gave more positive results than smear and culture examination. Out of the 50 clinical specimens 35 were found to be fungal culture positive. The sensitivity testing results of these fungal isolates showed that there was a good correlation between the in vitro results and the clinical response of the patient to antifungal therapy. Itraconazole exhibited maximum antifungal activity followed by fluconazole, ketoconazole and amphotericin B. CONCLUSIONS: PCR technology provides rapid and accurate diagnosis of fungal infection, however, it must be used with caution to avoid false positives.

PURPOSE: To assess the usefulness of protein electrophorograms and protein zymodemes in the identification and characterization of non tuberculous mycobacteria (NTM). METHODS: Cell free extracts (CFEs) from 22 mycobacterial isolates belonging to slow growing and other clinically relevant species were included in the study. The strains isolated from the environment were identified on the basis of their standard biochemical tests; pigmentation and growth characters. The CFEs were electrophoresed and stained for proteins and esterases. RESULTS: Most of the isolates identified on the basis of biochemical tests exhibited characteristic protein and esterase pattern for M.scrofulaceum, M.avium and M.xenopi. Others showed variations in their proteins and esterase pattern though they were identified as M.scrofulaceum, M.avium and M.xenopi. CONCLUSIONS: Based on these studies it appears that because of variability in the protein and isoenzyme patterns of NTM, it may be advisable to use them along with biochemical tests and other tests for identifying and characterizing the different mycobacterial species belonging to slow growers.

PURPOSE: To study the prevalence and predisposing factors of Aspergillus infection and correlate microscopic, culture and serological findings along with drug sensitivity. METHODS: Sputum samples from 123 patients of pulmonary disease with clinical suspicion of having fungal, especially Aspergillus infections, were examined microscopically and for culture. Minimum inhibitory concentration (MIC) of itraconazole was tested against the isolates. Serum samples from these patients were tested for precipitin against Aspergillus antigen using immunodiffusion (ID) technique. RESULTS: Aspergillus species were isolated in 20 (16.26%) cases and Aspergillus fumigatus was the predominant species isolated in 16 (80%) cases. Precipitins were detected in 29 (23.58%) cases. Serum samples collected from 50 healthy individuals to serve as controls showed no precipitin against Aspergillus antigen galactomannan. This fungus was found to be sensitive to itraconazole with MIC range 0.125-1µg/mL. CONCLUSIONS: Serological tests have an edge over routine smear and culture methods for the diagnosis of pulmonary aspergillosis. Itraconazole is more effective than amphotericin B and fluconazole in the treatment of aspergillosis.

PURPOSE: Serodiagnosis of tuberculosis in children, using available crude antigens, has been difficult. The tests lack sufficient sensitivity and/or specificity. In this study, western blot analysis of M. tuberculosis H37Rv culture filtrate antigen (CFA) was carried out, to identify diagnostically useful antigens. In addition, the CFA was also used in enzyme linked immunosorbent assay (ELISA), to measure antibodies of multiple isotypes. METHODS: Specific IgG, IgA and IgM antibodies were estimated in the sera from 26 clinically/bacteriologically diagnosed cases of childhood tuberculosis (CTB) and 61 normal children (CNHS), using culture filtrate antigen. Western blot analysis with culture filtrate antigen was carried out to qualitatively compare the antibody profile among the CTB, with childhood normal controls and adult TB. RESULTS: IgG positivity was only 7.6% with culture filtrate antigen in the CTB group, while 3.2% among the controls were also positive. However, the results of IgA and IgM isotypes were better. By combination of all the three isotypes an increased sensitivity of 57.7% with a specificity of 93.5%, was obtained. Immunoblot analysis revealed marked difference among antibodies in the region of 16, 19, 38 and 45kDa between CTB and CNHS. CONCLUSIONS: Our findings point to a limited sensitivity of 57.7% in ELISA with culture filtrate antigen. However, antibodies around 16, 19, 38 and 45kDa region may be useful in differentiating the CTB patients from CNHS by immunoblot assay.

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.

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.

To study the bacteriology of neonatal septicaemia in a tertiary care hospital of Northern India we prospectively enrolled all the suspected cases of neonatal septicaemia, which were not on antimicrobials. One to two millilitre of blood from these neonates was cultured in brain heart infusion broth. Out of 728 cases, 346 (47.5%) were positive on blood culture. The most frequent offender was Klebsiella spp. (24.5%) followed by Enterobacter spp. (22.8%). There was an overall predominance of gram negative organisms. Coagulase negative staphylococci (CONS) were more frequently isolated (16.5%) than Staphylococcus aureus (14%). More than 89% of the Staphylococci isolated were resistant to penicillin. None were resistant to vancomycin or teicoplanin. More than 95% of enterobacteria were resistant to anti gram negative penicillin group of drugs and more than 40% were resistant to extended spectrum cephalosporins. Ciprofloxacin and amikacin resistance was infrequent. Thus, initial therapy in our hospital may be aimed at Gram negative organisms and amikacin and ciprofloxacin may be used as first line drugs.

Advances in anti-fungal therapy necessitate the need for accurate identification of fungi especially yeasts to their species level for more effective management. Unlike the time consuming conventional methods of yeast identification using fermentation and assimilation patterns of various carbohydrates, the new commercialized yeast identification systems are simpler, rapid and are particularly easy to interpret. In our study, a new colorimetric yeast identification system-Fungichrom 1(International microbio, Signes, France) was evaluated against the conventional method to identify 50 clinical isolates of yeasts belonging to the genera -Candida, Cryptococcus, Geotrichum. 96% agreement was found between the two methods.

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.

Five patients with HIV associated cutaneous cryptococcal infection are reported.

A case of pulmonary infection, presenting with fever and productive cough (pseudohaemoptysis) was diagnosed as having infection with Serratia marcescens on performing culture and sensitivity tests. The organism was confirmed upto species level using the standard biochemical tests.