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Novel oxazolidinones were synthesized containing a number of substituted five-membered heterocycles attached to the 'piperazinyl-phenyl-oxazolidinone' core of eperezolid. Further, the piperazine ring of the core was replaced by other diamino-heterocycles. These modifications led to several compounds with potent activity against a spectrum of resistant and susceptible gram-positive organisms, along with the identification of ranbezolid (RBx 7644) as a clinical candidate.

A study of 157 randomly selected pregnant women from Aligarh India determined that 16 (10%) were positive for hepatitis B surface antigen (HBsAg); 12 (75%) women also had circulating hepatitis B (HBc) antibodies. 15 of these women developed hepatitis B infection in the third trimester of pregnancy. All neonates born to infected women were screened for hepatitis markers: eight (5%) were HBsAg-positive and seven (88%) also had anti-HBc suggesting active in utero infection. Hepatitis B transmission was significantly higher (p < 0.001) in infants delivered vaginally compared to cesarean section infants. Of the eight infants who acquired in utero infection one was stillborn and another had anencephaly and spina bifida. The risk of maternal transmission of hepatitis B virus has been estimated in other studies at 80-90%; more than 85% of these infants become chronic HBsAg carriers.

It has been reported recently that isoniazid resistant strains of Mycobacterium tuberculosis have lost the katG gene which encodes the catalase-peroxidase enzyme. A 35 mer oligonucleotide probe specific for the katG gene of M tuberculosis, 3' end-labelled with digoxigenin, was constructed and hybridised with DNA extracted from 26 clinical isolates of M tuberculosis under high stringency conditions. Twenty two of these isolates were resistant to 0.2 microgram/ml isoniazid and 20 to 1.0 microgram/ml isoniazid. Semiquantitative detection of catalase did not show any discrimination between isoniazid sensitive and resistant strains. The katG gene was present in all clinical strains of M tuberculosis. Therefore, complete deletion of the katG gene does not seem to be the mechanism of isoniazid resistance in M tuberculosis strains isolated from patients in India.

Salmonella typhimurium isolated from an infant and the powder milk as well as from three different epidemiologically unrelated patients had the same biochemical reactions, antibiogram, serotype and all were non-typable by phage typing. The clonal nature of epidemiologically related isolates was established by SDS PAGE analysis.

The first case of infection with Group B meningococcus in India is reported. The patient was a 4-month-old boy who presented with meningitis and died within 6 h of admission. Gram stain of CSF showed meningococci and latex particle agglutination test on CSF was strongly positive for Neisseria meningitidis serogroup B. The CSF was also positive for meningococcus by polymerase chain reaction using primers NM1 and NM6, which amplify a 650 bp region of the dihydropteroate synthase (dhps) gene of N. meningitidis.

Haemolytic Uremic Syndrome (HUS) been defined as the simultaneous occurrence of acute renal failure in children with haemolytic anemia and thrombocytopenia. This clinical condition that has been recognized is an important cause of acute renal failure in children.1

In this study, we report a modified procedure for extraction of high-quality genomic DNA that is rapid, simple, biologically nonhazardous, and generally applicable to pathogenic bacteria. Bacterial cells were pretreated with 70% ethanol prior to enzymatic digestion with lysozyme. Exposure of bacterial cells to 70% ethanol sterilized the cultures, making the process biologically safe and increased the susceptibility of the cells to lysozyme-induced lysis. Consistently high yields of genomic DNA (mean average yield, 0.5-2.5 mg/ml) were obtained from 465 isolates representing over 30 clinically important bacterial species. Genomic DNA obtained was determined to be suitable for further analysis, including bacterial fingerprinting techniques like restriction endonuclease analysis, Southern hybridization, and repetitive PCR. Availability of a generally applicable procedure for extraction of high-quality and high-quantity genomic DNA would be immensely beneficial for laboratories engaged in molecular surveillance of nosocomial and community-based outbreaks.

Thirty patients operated for nasal polypi and 15 age and sex matched controls were taken for study. Estimation of albumin, IgG, IgA, IgM and IgE was done in serum and nasal polyp fluid. Histopathology of polypi was undertaken in order to divide polypi into allergic and inflammatory groups and to study the immunoglobulin profile in these two groups. Allergic polypi were found to be more common than inflammatory polypi. The inflammatory polyp fluid IgA level (208.19 ± 59.33 mg/dl) was significantly raised (p

A total of 116 isolates from patients attending the out-patient department at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbiological techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were further characterized at molecular level. The multi-drug loci corresponding to rpo beta, gyr A, kat G were studied for mutation(s) by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) technique. The SSCP positive samples were sequenced to characterize the mutations in rpo beta, and gyr A loci. While previously reported mutations in the gyr A and rpo beta loci were found to be present, several novel mutations were also scored in the rpo beta locus. Interestingly, analysis of the gyr A locus showed the presence of point mutation(s) that could not be detected by PCR-SSCP. Furthermore, rifampicin resistance was found to be an important marker for checking multi-drug resistance (MDR) in clinical isolates of Mycobacterium tuberculosis. This is the first report on molecular genetic analysis of MDR tuberculosis from India, and highlights the increasing incidence of MDR in the Indian isolates of M. tuberculosis.

Multidrug-resistant strains of Mycobacterium tuberculosis seriously threaten tuberculosis (TB) control and prevention efforts. Molecular studies of the mechanism of action of antitubercular drugs have elucidated the genetic basis of drug resistance in M. tuberculosis. Drug resistance in M. tuberculosis is attributed primarily to the accumulation of mutations in the drug target genes; these mutations lead either to an altered target (e.g., RNA polymerase and catalase-peroxidase in rifampicin and isoniazid resistance, respectively) or to a change in titration of the drug (e.g., InhA in isoniazid resistance). Development of specific mechanism-based inhibitors and techniques to rapidly detect multidrug resistance will require further studies addressing the drug and drug-target interaction.

The application of molecular biology methods has contributed significant insight into the epidemiology of infections caused by Mycobacterium tuberculosis. However, most of the techniques remain out of reach of laboratories in the tropics. We describe here a simple method for extraction of DNA from the pathogen, a first step in the application of molecular biology tools.

For the diagnosis of extrapulmonary tuberculosis in adults and all forms of tubercular infections in children, microscopic and cultural techniques have (seen shown to be inadequate. Many serological techniques have been employed for non culture diagnosis of tuberculosis. Early promising results have repeatedly given way to subsequent findings of non-specificity. Major mycobacterial antigens have been shown to be heat shock proteins which are highly conserved in nature. DNA probes for tuberculosis are specific but have a sensitivity equivalent to AFB smear examination. Polymerase Chain Reaction (PCR) with its ability to selectively amplify DNA fragments of interest offers a potentially powerful technique for the rapid, specific and sensitive diagnosis of tuberculosis. Samples from partially treated patients could be culture negative but can be detected by PCR.

Circulating immune complexes (CIC) were assayed in 100 cases of tuberculosis and 30 age matched control children. The estimation was done by PEG assay before the commencement of antitubercular therapy. CIC were present in only 3.3% of the control children as compared to 68% of children with tuberculosis. The presence of CIC was observed to vary with the type of tuberculosis. The percentage positivity was highest (100%) in children with miliary tuberculosis. Subsequent estimation of CIC done after one and three months of antitubercular therapy showed a marked decrease in the percentage of positive cases (6.1 and zero percent respectively).

The purpose of this study was to simultaneously screen for Extended-spectrum b-lactamases (ESBL) and AmpC b-lactamases in gram negative clinical isolates from four tertiary care hospitals and further to compare two detection methods three-dimensional extraction method and AmpC disk test for AmpC b-lactamases. A total of 272 isolates were screened for ESBL and AmpC β-lactamase by modified double disk approximation method (MDDM). Synergy observed between disks of ceftazidime/cefotaxime and clavulanate were considered as ESBL producer. Isolates showing reduced susceptibility to either of the test drugs (ceftazidime or cefotaxime) and cefoxitin were considered as presumptive AmpC producers and further confirmed by three-dimensional extraction method and AmpC disk test. A total of 173 (64%) of the isolates were found to be ESBL positive and 61 (23%) showed resistant to cefoxitin. ESBL was detected in 80 (62%) isolates of E. coli and 71 (73%) of Klebsiella spp. The occurrence of AmpC b-lactamases was found to be 8% (22) of the total isolates and the two detection methods for AmpC b -lactamase showed concordant results. Screening for ESBL and AmpC can be simultaneously done by MDDM method and confirmation for AmpC β-lactamase should be carried out routinely in tertiary care hospitals by AmpC disk test, as it is a simple and rapid procedure.

The objective of this study was to investigate screening methodologies, to detect Staphylococcus aureus strains with decreased susceptibility to vancomycin. Three methods were used to screen 160 Staphylococcus aureus clinical isolates along with ATCC quality control strains. Subsequently, MIC of all these 160 strains were determined by NCCLS methodology. The MIC of all the 160 clinical isolates was < 4µg/mL and were classified as vancomycin susceptible by NCCLS criteria but 23 strains were positive by Hiramatshu method, two grew on MHA (5µg/mL vancomycin) while CDC method correctly identified no vancomycin intermediate S.aureus (VISA) or vancomycin resistant S.aureus (VRSA) strains with reference to there MIC. CDC method was found to be the most appropriate screening methodology for detection of VISA or VRSA for diagnostic laboratories.

A study of 125 uncomplicated urethritis in males were selected at and analysed from different angles in view the changing facets of gonococcal infection and its impact at the present time.

AIMS--To evaluate a safe sputum processing method for detection of tuberculosis in developing countries. METHODS--A sample processing method was developed in which acid fast bacilli were killed with 1% sodium hypochlorite and concentrated by flotation on a layer of xylene before staining by the Ziehl Neelsen or auramine O methods. RESULTS--Best results were obtained by auramine O staining after flotation. Staining by the Ziehl Neelsen method after flotation gave better results than direct Ziehl Neelsen staining without flotation. CONCLUSIONS--The flotation method with Ziehl Neelsen staining offers advantages for smear preparation in the tuberculosis control programmes of developing countries.