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T D Chugh

Publications and source records attributed to T D Chugh.

134 records · Page 8Linked to original sources
PubMedDate not supplied

Improved detection of mycobacterial antigens in clinical specimens by combined enzyme-linked immunosorbent assay.

Three types of antibodies against cellular and secretory-excretory protein antigens were simultaneously used for the direct detection of mycobacterial antigens in sputum and cerebrospinal fluid (CSF) specimens, using enzyme-linked immunosorbent assay (ELISA). The antibodies consisted of in-house raised and prepared anti-whole-cell, heat-killed, and sonicated Mycobacterium tuberculosis, anti-secretory-excretory protein extract of bacilli Calmette-Guerin (BCG) strain, and commercially available anti-BCG. Sputum specimens comprised 24 smear positive, culture positive, and 47 smear-negative, culture positive (SNCP), from patients with pulmonary tuberculosis, as well as 45 smear-negative, culture-negative (SNCN) control samples. The CSF specimens included 18 SNCPs from patients with tuberculous meningitis and 18 SNCN controls. The sensitivity of the individual tests for sputum and CSF specimens ranged from 70% to 79% and 72% to 89%, respectively, whereas in the combined tests it reached 86%-96% for sputum specimens and 100% for CSF specimens. The specificity of ELISAs for sputum specimens was lower in the combined (73%-87%) than in the individual (87%-98%) tests, whereas for CSF specimens it was 100% in all tests. Thus, the combined ELISA approach for mycobacterial antigen detection provides a rapid and reliable laboratory adjunct in the diagnosis of patients with tuberculosis.

Antibodies, Bacterial↗
PubMedDate not supplied

A study of the enzymatic profile of soil isolates of Nocardia asteroides.

In this study, using the API-ZYM system, we have reported the enzyme profile of 42 soil strains and 2 clinical strains of Nocardia asteroides isolated locally. Of the 19 enzymes tested, only 7 were demonstrable in over 90% of the soil isolates. These included alkaline phosphatase, esterase lipase, leucine arylamidase, acid phosphatase, phosphohydrolase, alpha-glucosidase and beta-glucosidase. In addition, beta-galactosidase activity was demonstrated in all the strains by the O-nitrophenyl-beta-D-galactopyranoside (ONPG) test. The enzymes which were not demonstrable in > 95% of the strains included valine arylamidase, cystine arylamidase, trypsin, chymotrypsin, alpha-galactosidase, beta-glucoronidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase and alpha-fucosidase. With the exception of valine arylamidase, which was lacking in all but one isolate, the enzyme profiles of the soil isolates were comparable with the clinical isolates of N. asteroides reported in previous studies. The reasons for this difference in the two sets of isolates is not clear. The study reinforces the view that specific differences in the enzymatic profiles of Nocardia species could be used for their rapid identification. However, more extensive studies are needed to establish the reproducibility of this method. To the best of our knowledge, this is the first study of the enzymatic profile of soil isolates of N. asteroides originating from a single geographic region.

Esterases↗
PubMedDate not supplied

Antimicrobial susceptibility, phage typing and plasmid profile of Salmonella enterica serotype paratyphi A strains isolated in Kuwait.

OBJECTIVE: To determine the antimicrobial susceptibility, phage type and plasmid profile pattern of Salmonella enterica serotype paratyphi A strains isolated in Kuwait. MATERIAL AND METHODS: From January 1995 to December 1999, 106 strains of S. enterica serotype paratyphi A isolated from an equal number of cases of enteric fever, attending the Infectious Disease and Mubarak Al-Kabeer Hospitals in Kuwait were investigated. The isolates were tested for antimicrobial susceptibility to 8 commonly used antimicrobial agents. Their phage type and plasmid profile patterns were determined using an international set of phages and Qiagen plasmid mini kit, respectively. RESULTS: All of the isolates were susceptible to ciprofloxacin, cefuroxime, ceftazidime, piperacillin and co-trimoxazole. One hundred isolates were susceptible to ampicillin, 99 to chloramphenicol and 98 to tetracycline. None of the isolates was multidrug resistant. Sixty-six percent of the isolates were phage type I, 27.4% phage type II and 6.6% were untypable. All phage type I and untypable strains had 3 plasmids of 2.2, 5 and 20 kb, whereas phage type II strains had only 1 plasmid of 20 kb. CONCLUSION: The findings indicate that while all of the isolates of the S. enterica serotype paratyphi A were susceptible to 4 of the drugs tested, some were resistant to ampicillin, chloramphenicol or tetracycline, thereby indicating the need for continued surveillance and monitoring of antimicrobial susceptibility of these isolates.

Bacteriophage Typing↗
PubMedDate not supplied

Significance of atypical pathogens among community-acquired pneumonia adult patients admitted to hospital in Kuwait.

OBJECTIVES: The aim of this study is to determine the microbial etiology and severity of community-acquired pneumonia (CAP) in Kuwait. SUBJECTS AND METHODS: The severity of consecutive adult CAP cases admitted to 3 hospitals over a 1-year period was classified according to the Pneumonia Outcome Research Team (PORT) severity index. The microbial etiology was determined using standard methods for bacteria and serological tests for atypical and viral pathogens. RESULTS: The study population was 124 of the 135 admissions; 63 female, 61 male; mean age 41.3+/-18 years. The severity class distribution was: class I 31%, class II 37%, class III 17%, class IV 13%, and class V 2%. Etiological agents were identified from 44 patients (35%), with one pathogen in 31 (25%), two in 9 (7%), and three or more in 4 (3%). The most common pathogens identified were: Mycoplasma pneumoniae in 14 patients (11%), Legionella pneumophila in 10 (8%), Chlamydia pneumoniae in 8 (6%), influenza B virus in 8 (6%), influenza A virus in 5 (4%), Haemophilus influenzae in 4 (3%), Streptococcus pneumoniae in 3 (2%), Staphylococcus aureus in 3 (2%), gram-negative enterobacteria in 5 (4%), Moraxellacatarrhalis in 2 (2%), and viruses in 4 (3%). The yields from laboratory tests were 48% for paired serology, 20% from adequate sputum sample, and 3% from blood culture. CONCLUSION: Our study shows that a large percentage of mild CAP cases are admitted to hospitals in Kuwait. Atypical pathogens have a significant role in the etiology of CAP. There is overtreatment of CAP with a combination treatment consisting mainly of third-generation chephalosporins and macrolides.

Adolescent↗
PubMedDate not supplied

Molecular diagnosis of antimicrobial resistance.

Advances in molecular technology have helped in better understanding of mechanisms and diagnosis of diseases in many medical fields. Several molecular techniques are available for determining the genotypic drug-resistance and monitoring epidemic spread of a particular antimicrobial resistance gene in a hospital or patient population. The molecular (genotypic) testing has several advantages over conventional (phenotypic) testing in being faster and unambiguous, more accurate, able to detect masked resistance and can serve as a "gold" or "reference" test for detecting antibiotic resistance genes. This article addresses these molecular tests with their application and limitations and provide examples of their use especially in Mycobacterium tuberculosis and methicillin resistant Staphylococcus aureus.

DNA, Bacterial↗
PubMedDate not supplied

Invasive fungal infections in Kuwait: A retrospective study.

A retrospective review of a five year period (1994-1998) revealed that opportunistic mycoses caused by ubiquitous fungal pathogens are a serious problem in the immunocompromised patient population of Kuwait. Patients with renal transplantation and diabetes mellitus were most susceptible to aspergillosis, cryptococcosis, and zygomycosis, whereas patients with candidemia/hematogenous candidiasis had multiple risk factors. Basidiobolomycosis of the rectum in a Bangladeshi male, cryptococcosis due to Cryptococcus neoformans var. gatti in an AIDS patient,fungal peritonitis due to Absidia corymbifera in a patient on peritoneal dialysis, and endocarditis due to Aspergillus terreus detected by direct microscopic examination and culture of the blood clot are some of the notable cases diagnosed during the period under review. The predominance of Candida species other than C. albicans as bloodstream pathogens is another noteworthy observation. Although outbreaks of C. parapsilosis candidemia in neonatal intensive care units contributed significantly to this shift in favour of non-albicans Candida species, a surveillance strategy comprising of molecular, epidemiologic and antifungal susceptibility studies is warranted. With the proposed expansion of organ and bone marrow transplantation facilities in Kuwait, the incidence of opportunistic fungal infections is likely to increase.

Adult↗
PubMedDate not supplied

Cytodiagnosis of tuberculous lymphadenitis. A correlative study with microbiologic examination.

One hundred two of 272 cases of cytodiagnosis of tuberculous lymphadenitis were subjected to mycobacterial examination by Ziehl-Neelsen staining on direct and concentration smears and by culture. Cytomorphologically the cases were categorized into four types: 1, predominantly necrotic material; 2, typical caseating epithelioid cell granulomas and giant cell formation; 3, only noncaseating epithelioid cell granulomas with or without giant cells; and 4, doubtful presence of epithelioid cells. Ziehl-Neelsen staining for acid-fast bacilli (AFB) was positive in 25% in direct smears, 26.5% in concentration smears and 29.5% in both combined. The cultures for mycobacteria were positive in 49%; combined smear and culture positivity was found in 56.9%. Maximum culture positivity was seen in cases with type 1 smears (56.9%) followed by types 2 (44%) and 3 (40%). The percentage of AFB positivity was similar in type 1 and type 2 smears (32.2% and 30%, respectively); however, AFB were present in large numbers in type 1 smears as compared to type 2 and 3 smears. In type 3 smears AFB positivity was found in 20% of cases. Cases with type 4 smears were negative for AFB in smears and culture. In eight cases (7.8%) the smears were positive for AFB, whereas the cultures were negative, indicating that negative culture examination still does not exclude the possibility of tuberculosis. However, culture is essential to a characterization and determination of drug sensitivity.

Adult↗