Tuberculosis, as yet, is far from being controlled. Several reasons can be attributed to this, a major contributing factor being the development of resistance to the currently available drugs due to the successful adaptation of the pathogen. Most of the inferences about the pathogen are based on the observation of mycobacteria grown in synthetic media in vitro and of the mycobacteria maintained in macrophages simulating the in vivo conditions. Molecular studies in mycobacteria had been slow to come due to the difficulty in the generation of mutants. However, new technologies that have now been developed for studying in vivo expressed molecules in other bacterial systems are being successfully applied to mycobacteria, especially the pathogenic M. tuberculosis. Additionally, an equally important factor in the study of the disease is the genetic predisposition of population to the infection. New findings link the Nramp1 and Toll receptor polymorphisms to susceptibility to infectious diseases.

PURPOSE: Due to relatively complex nature of molecular typing systems for M. tuberculosis as well as lack of applicability of some of the probes, there is a need for alternate procedures for molecular epidemiology. In this study the usefulness of RAPD analysis for typing of Indian strains of M.tuberculosis was investigated. METHODS: One hundred and three coded isolates from different parts of the country were analysed by Random amplified polymorphic DNA (RAPD) technique. Purified and amplified DNA from cultures were analysed by ethidium bromide staining after electrophoresis. The bands were confirmed by densitometry and the patterns were analysed by hierarchical cluster analysis. RESULTS: The patterns elicited by the analysis appeared to be quite discriminatory and characteristic. CONCLUSIONS: Clustering observed among isolates attending the same hospital indicates future application potential of RAPD analysis for molecular epidemiology of tuberculosis in India.

PURPOSE: To assess role of oral flora in causing bacteraemia following dental manipulations. METHODS: Fifty patients undergoing dental manipulations were assessed to study the incidence and nature of bacteraemia following dental procedures with special emphasis on Actinomyces. RESULTS: Incidence of bacteraemia was seen to be 80% of which Actinomycotic bacteraemia was found to be 30 %. Common species of Actinomyces isolated were A.viscosus (58.33 %), A.odontolyticus (8.33 %) and A. naeslundi (8.33 %). Aerobic bacteraemia was seen in 48% patients. Common aerobes isolated from bacteraemia following dental procedures were alpha haemolytic streptococci (25.93 %) and diphtheroides (20.38 %). Anaerobic bacteraemia was seen in 6% patients. Common Anaerobes isolated were Peptostreptococcus spp (33.32 %), Prevotella spp. (16.66%) and Bacteroides spp (16.66%). Mixed aerobic and anaerobic bacteraemia was present in 26 % of the patients. CONCLUSIONS: Actinomycotic bacteraemia was more commonly seen in patients with periodontal infections. Thus, prophylactic measures need to be instituted in such patients to prevent cervicofacial, thoracic or abdominal Actinomycosis developing later on.

PURPOSE: To find prevalence of drug resistance in Mycobacterium tuberculosis isolated from patients attending SMS Medical College, Jaipur during 1997-99. METHODS: Sputum samples from 164 patients with pulmonary tuberculosis were processed and cultured on Lowenstein Jensen medium and M.tuberculosis isolates were tested for drug sensitivity. RESULTS: M. tuberculosis was isolated in 122/164 (74.3%) samples and comprised 97.6% (122/125) of mycobacterial isolates. There were only three isolates of nontuberculous mycobacteria -one each of M.kansasii, M.avium and M.fortutium. Primary drug resistance in M.tuberculosis was estimated to be 3/44 (6.8%) to rifampicin, 6/44 (13.6%) to isoniazid and 2 strains (4.5%) were multi drug resistant i.e. resistant to both rifampicin and isoniazid. Among the isolates from cases with previous history of treatment of varying duration (acquired drug resistance) resistance to rifampicin was estimated to be 28.2% and for isoniazid to be 39.7%. 24.3% strains of these drug resistant isolates were multi drug resistant. CONCLUSIONS: While this information may not reflect true prevalence of drug resistance in the region this may help in further planning long term surveillance studies to know the trend of drug resistance in this area.

PURPOSE: To study the combined role of Casoni test and indirect haemagglutination (IHA) test in the diagnosis of hydatid disease. METHODS: Twenty eight suspected cases of hydatid disease were subjected to Casoni intradermal test using commercially available antigen (Span Diagnostics, India) after collecting pre-test serum samples. The serum samples were tested by IHA using an indigenously developed IHA test. RESULTS: Considering the clinical diagnosis of hydatid disease as the gold standard, the specificity of both Casoni test and IHA was 47%, however, the sensitivity of IHA was higher (81.8%) than Casoni test (63.8%). With the two tests considered together the sensitivity was 90.9%. CONCLUSIONS: Combined use of Casoni test and IHA test could establish presumptive and cost effective diagnosis in upto 90.9% of clinically suspected cases of hydatid disease.

PURPOSE: To ascertain the relationship between seropositivity to chronic infections with Helicobacter pylori, Chlamydia pneumoniae and Cytomegalovirus (CMV) and acute coronary syndromes and association of each of these infective agent with biochemical parameters and cardiovascular risk factors. METHODS: The present study was a case-control study involving 117 patients [unstable angina (UA) n=101 and chronic stable angina (CSA) n = 16] attending cardiology clinic. The cases were aged 35-79 years and they were compared with age, sex and socio-economic status matched controls without evidence of coronary artery disease (CAD). RESULTS: Fifty seven (58%) patients with UA and 9(56%) patients with CSA were seropositive for H. pylori. Sixty seven (66%) subjects with UA and 15(94%) patients with CSA subjects were seropositive for C.pneumoniae. Two (2%) patients with USA were seropositive for Cytomegalovirus (CMV). Seropositivity in normal subjects for H. pylori, C. pneumoniae and CMV was 7(43.25%), 10(62.5%) and 1(6.25%) respectively. In linear regression analysis seropositivity of CMV showed positive association with HDL-C (P< 0.05). No significant association of infective agents and coronary syndromes was observed. CONCLUSIONS: Higher levels of lipids, lipoproteins, C-reactive protein and higher percentage of coronary risk factors in patients seropositive for H. pylori in UA suggests the role of infective agents in pathogenesis of atherosclerosis.

PURPOSE: To determine the prevalence of intestinal parasites in HIV patients with and without diarrhoea in Chennai. METHODS: A total of 150 stool samples, 41 - acute diarrhoea, 59 - chronic diarrhoea and 50 control samples without diarrhoea were collected and examined for enteric parasites by microscopy. RESULTS: Enteric parasites were detected in 39% patients with diarrhoea compared to 14% in patients without diarrhoea. Isospora belli was found in 18.6% (11/59) of chronic diarrhoea and 7.3% (3/41) in acute diarrhoea (P > 0.2). Cryptosporidium was detected in 7 cases each in acute and chronic diarrhoea, which was statistically insignificant as compared to the control group (P >0.05). Microsporidia and Cyclospora cayetanensis associated diarrhoea were detected in only one chronic case each 1/59 (1.69 %). CONCLUSIONS: Isospora belli appeared to be a predominant parasite associated with diarrhoea among HIV patients. Detection rate of Microsporidia and Cyclospora was found to be very low.

PURPOSE: To examine the incidence of extended spectrum b lactamase (ESbL) producing strains and multidrug resistant strains of Klebsiella pneumoniae isolated from children between 0-5 years of age. METHODS: Multidrug resistance and ESbL production was studied in a total of 120 isolates of Klebsiella pneumoniae obtained from patients aged 0-5 years. RESULTS: 95% of the isolates showed resistance or decreased susceptibility to atleast one of the three third generation cephalosporins [3GC (ceftazidime, cefotaxime, ceftriaxone)] used for the study. 87% of the isolates showed resistance to all the three 3GC antibiotics and this resistance to all the three 3GC was found to coexist with resistance to other antibiotics. All the isolates were found sensitive to the antibiotic imipenem. ESbL production was detected in 8 strains of Klebsiella pneumoniae. The ESbL activity could be experimentally transferred to recipient E.coli (K12 J62-2). Resistance to b-lactam antibiotics was co-transferred with resistance to gentamicin. CONCLUSIONS: This study has shown the incidence of ESbL producing Klebsiella pneumoniae strains among children in Chennai. Tests for the detection of ESbL producing Klebsiella strains should be carried out in all diagnostic centers routinely and the therapeutic use of all the 3GC should be avoided against Klebsiella strains that appear resistant to any third generation antibiotic.

Uropathogenic strains from inpatient and outpatient departments were studied from April 1997 to March 1999 for their susceptibility profiles. The various isolates were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii and Enterococcus faecalis. Antibiotic susceptibility pattern of these isolates revealed that for outpatients, first generation cephalosporins, nitrofurantoin, norfloxacin/ciprofloxacin were effective for treatment of urinary tract infection but for inpatients, parenteral therapy with newer aminoglycosides and third generation cephalosporins need to be advocated as the organisms for nosocomial UTI exhibit a high degree of drug resistance. Trimethoprim and sulphamethoxazole combination was not found to be effective for the treatment of urinary tract infections as all the uropathogens from inpatients and outpatients showed high degree of resistance to co-trimoxazole. Culture and sensitivity of the isolates from urine samples should be done as a routine before advocating the therapy.

Between July 1997 and December 2000, 1616 HIV seropositive persons were identified by Western Blot test at the School of Tropical Medicine, Kolkata. Four hundred seventy two (29.2%) of them had generalized lymphadenopathy. CD4 count could be done in only 54 of these 472 subjects (11.4%). These 54 patients, consisting of 40 males (74%) and 14 females (26%) were the subjects of the study. Their mean age was 29.5 years. In all these subjects, FNAC was done from the enlarged lymph nodes (non-inguinal). Reactive hyperplasia was seen in 30 cases (55.5%) whose absolute CD4 count varied between 411-945 cells/µL (median value 670 cells/µL). Evidence of tuberculous lymphadenitis was detected in 22 (41%) with CD4 counts varying between 113 and 422 cells/µL (median value 212 cells/µL). Non-Hodgkin lymphoma was diagnosed in 2 cases (3.7%) with CD4 count 79-113 cells/µL. All patients had evidence of HIV-1 infection, excepting one case of dual infection (HIV-1 and 2).

Laboratory diagnosis is the mainstay in the diagnosis of HIV infection in an individual. The wide range of diagnostic kits available, for the detection of anti HIV antibodies, makes it mandatory that the kits are evaluated before they are made available in the market. We evaluated the performance of a Microlisa HIV kit (J.Mitra & Co.)† using a panel of HIV reactive and non reactive clinical specimens. The sensitivity and specificity of the kit were found to be 100% as compared to the UBI HIV 1/2 EIA kit. The ease of testing, the assay characteristics including efficiency of the Microlisa favour its use by laboratories as a primary screen for HIV infection.

A total of 500 antenatal women in their first or second trimesters were screened over a period of 2 years for asymptomatic bacteriuria. Out of them, 8.4% (42) were culture positive. A control group of 100 non-pregnant women, both married and unmarried, was also simultaneously screened. The control group yielded an overall culture positivity of 3% (4% in the married non-pregnant women and 2% in the unmarried women). Primigravida had highest percent culture positivity of 66.6%. The incidence was higher in less than 20 years age group i.e. 71.42%. Of the screening tests, Gram stained smear when compared with the standard loop method, showed the highest sensitivity of 95.2%. The specificity of the screening tests was high [Gram stained smear (98.6%), catalase test (97.1%) and pus cell count(96.5%)]. Escherichia coli was the most common organism isolated in the test and control groups. The organisms were sensitive to cephalexin, nitrofurantoin, amoxycillin and norfloxacin in decreasing order. Incidence of prematurity was 75% and that of low birth weight was 50% in untreated patients.

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 µg/mL.

A total of 120 blood samples from neonates presenting with clinical signs of septicaemia were subjected for culture using brain heart infusion agar biphasic medium (BHI BPM) and glucose broth. Bacterial agents were isolated from 48 numbers (40%) of cultures. Gram-negative bacilli were isolated in maximum percentage (88.45%) of cases whereas gram-positive bacteria (coagulase negative staphylococci and group B streptococci) in 11.6% of cultures. E.cloacae (39.5%) was maximally isolated among the pathogenic bacteria followed by K.pneumoniae (23.2%), E.coli (11.6%) and others like Acinetobacter spp. (6.9%), Citrobacter freundi (4.6%) and P.mirabillis (2.3%). All the gram-negative bacilli isolates showed 100% susceptibility to amikacin, whereas 85% of E.cloacae isolates were sensitive to the same. Thus E.cloacae was found to be a predominant moderately sensitive pathogen in neonatal septicemia.

Mixed infection with multiple Salmonella serotypes in the same patient is an unusual finding. We present a case of enteric fever in which the blood culture was sterile and Widal test was negative. The culture of the bone marrow yielded Salmonella typhi and Salmonella paratyphi A.

A case of strongyloidiasis in common variable immunodeficiency is reported here. The patient was given several courses of albendazole without any response.