Search PubMed⌕ Search

Biomedical subjects

T D Chugh

Publications and source records attributed to T D Chugh.

At least 19 recordsLinked to original sources
PubMed2002

Antibiotic resistance of enterococci isolated at a teaching hospital in Kuwait.

Enterococci isolated in a teaching hospital were studied for their resistance to different antibiotics. Minimum inhibitory concentrations to high-level aminoglycosides and glycopeptide antibiotics were determined by agar dilution and E-test methods respectively. Genes encoding aminoglycoside-modifying enzymes were detected by the polymerase chain reaction (PCR). 195 enterococci were isolated from urines (54.3%), wounds (16.4%), blood (10.2%), and miscellaneous sources (18.9%). They consisted of E. faecalis (88.7%), E. faecium (9.2%), E. casseliflavus (1.5%) and E. bovis (0.5%). None of the enterococci produced penicillinase but 3.5% of them were resistant to ampicillin. They were also resistant to high-level gentamicin (15.9%), kanamycin (22.0%), streptomycin (21.0%), tetracycline (65.1%), erythromycin (62.6%), ciprofloxacin (36.1%), chloramphenicol (26.1%), vancomycin (3.0%) and teicoplanin (2.0%). Most of the high-level aminoglycoside-resistant isolates contained genes coding the bifunctional aminoglycoside modifying enzymes AAC(6')-APH(2"), APH(3') and ANT(6') but not the ANT(4') enzyme. The results demonstrated a low prevalence of vancomycin resistance among Enterococci in this hospital.

Academic Medical Centers↗
PubMed2002

Prevalence of S315T mutation within the katG gene in isoniazid-resistant clinical Mycobacterium tuberculosis isolates from Dubai and Beirut.

OBJECTIVE: To determine the prevalence of S315T mutation within the katG gene that confers clinically significant resistance to isoniazid in isoniazid-resistant Mycobacterium tuberculosis isolates recovered from tuberculosis patients in Dubai and Beirut. METHOD: A total of 28 and 17 isoniazid-resistant and seven and six susceptible clinical M. tuberculosis isolates from Dubai and Beirut, respectively, were tested. The presence of S315T mutation in the katG gene was detected by amplification of the DNA region around codon 315 by polymerase chain reaction followed by restriction digestion with Msp I to generate restriction fragment length polymorphism. The genotyping of the isolates carrying S315T mutation was carried out by touchdown double-repetitive-element PCR (DRE-PCR). RESULTS: The mutation S315T was detected in 18 (64%) of 28 isoniazid-resistant isolates from Dubai and in six (35%) of 17 resistant strains from Beirut. None of the susceptible strains contained this mutation. The genotyping studies showed that the majority of the isolates carrying the S315T mutation exhibited unique DNA banding patterns. CONCLUSION: The data show a varying prevalence of S315T mutation within the katG gene in M. tuberculosis strains isolated from the two geographical locations, Dubai and Beirut.

Antitubercular Agents↗
PubMed2000

Characterization of rpoB mutations in rifampin-resistant Mycobacterium tuberculosis isolates from the Middle East.

The nature and frequency of mutations in the rpoB gene of rifampin-resistant clinical Mycobacterium tuberculosis isolates vary considerably according to geographical locations. There is no information on the prevalence of specific mutations in clinical M. tuberculosis strains isolated from patients in Middle-Eastern countries. In this study, 13 rifampin-resistant and 6 susceptible clinical M. tuberculosis isolates were tested for identification and characterization of mutations in the rpoB gene by INNO-LiPA Rif. TB kit and DNA sequencing of the PCR amplified target DNA. The kit identified all six susceptible strains as rifampin-sensitive and the DNA sequence of the amplified rpoB gene in the target region matched perfectly with the wild-type sequence. The kit identified 12 resistant isolates as rifampin-resistant with specific detection of mutations in 8 isolates while one of the rifampin-resistant strain was identified as rifampin-susceptible. DNA sequencing confirmed these results and, in addition, led to the specific detection of mutations in 4 rifampin-resistant isolates in which specific base changes within the target region could not be determined by the INNO-LiPA Rif. TB kit. The majority (8 of 13) of resistant isolates involved base changes at codon 531 of the rpoB gene. Mutations at codon position 531 within the rpoB gene have also been reported in majority of rifampin-resistant strains from Greece and St. Petersburg, Russia but not from other geographical locations.

Antibiotics, Antitubercular↗
PubMed2000

Antimicrobial susceptibility profile of soil isolates of Nocardia asteroides from Kuwait.

OBJECTIVES: To find the antimicrobial susceptibility profile of 42 soil isolates of Nocardia asteroides against 14 antimicrobial agents representing beta-lactams, aminoglycosides, ciprofloxacin, minocycline, erythromycin and third generation cephalosporins. METHODS: The antimicrobial susceptibility was determined by the disk diffusion method using Mueller-Hinton agar medium. A homogeneous suspension giving an inoculum of 106-108 CFU/mL was used to streak the plates. The zone of inhibition was read after 36-48 h of incubation at 37 degrees C. RESULTS: All the soil isolates of N. asteroides were susceptible to amikacin, imipenem and tobramycin. Susceptibility to cephalosporins was quite variable; 86% of the isolates were susceptible to cefotaxime, 57% to ceftriaxone and 40% to cefamandole. Fifty-seven per cent of the isolates showed intermediate susceptibility to cefamandole, 33% to ceftriaxone and 5% to cefotaxime. Ninety-three per cent of the isolates were resistant to sulfamethoxazole alone or in combination with trimethoprim. CONCLUSIONS: The study reports a wide variation in the antimicrobial susceptibility profile of soil isolates of N. asteroides originating from a single geographical area. Of interest is the finding that over 90% of N. asteroides isolates were resistant to sulfamethoxazole without any previous exposure to this drug. This may have serious therapeutic implications as sulphonamides or the combination of trimethoprim-sulfamethoxazole is the therapy of choice for nocardiosis. Demonstration of resistance to beta-lactam antibiotics may be attributed to the presence of beta-lactamases which was detectable in > 90% of the soil strains of N. asteroides. The study underscores the importance of antimicrobial susceptibility testing for clinical isolates of Nocardia since individual strains show considerable differences in their susceptibility patterns necessitating therapeutic adjustments.

Anti-Bacterial Agents↗
PubMed2000

Xanthomonas maltophilia infection in chronic peritoneal dialysis patients.

Xanthomonas maltophilia infection has only been occasionally reported in patients receiving chronic peritoneal dialysis. We describe four cases of Xanthomonas maltophilia infection associated with chronic peritoneal dialysis. Two patients presented with peritonitis and two with exit site infection. All patients were diabetics, who immediately prior to the study had not received antibiotic therapy. Failure to respond to multiple antibiotic therapy resulted in catheter removal in both patients with peritonitis. In those patients with only exit site infections, dialysis could be continued following antibiotic therapy and catheter replacement in one. Catheter loss in our patients was directly attributed to peritonitis with Xanthomonas maltophilia infection.

Adult↗
PubMed1999

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis and plasmid profile of soil and clinical isolates of Nocardia.

The aim of this study was to develop a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay for generic and species-specific differentiation of Nocardia from other morphologically similar bacterial pathogens. To examine the utility of the PCR-RFLP approach in species identification, genomic DNA was prepared from 40 soil isolates, 10 clinical isolates and 8 reference strains of Nocardia. A set of oligonucleotide primers was designed from the consensus sequence of the highly conserved groEL gene that encodes the 65-kDa heat shock protein (hsp 65). The primers selectively amplified 422 bp DNA from the genomic DNA of all Nocardia species and isolates. The digestion of the amplicons with the restriction enzyme MspI produced DNA fragments that could differentiate between different Nocardia species regardless of their origin. Additionally, the RFLP patterns obtained with restriction enzymes MspI and BsaHI resulted in the differentiation of six Nocardia species which were earlier identified by biochemical tests. Apart from soil isolates of N. asteroides, which had shown some degree of genotypic polymorphism with BsaHI, the remaining taxa yielded more consistent results. Our results on the isolation of plasmids indicated that their occurrence is not a consistent feature in Nocardia species. It is neither related to the source of origin (clinical versus saprobic), nor to virulence, anti-microbial resistance or species specificity.

Humans↗
PubMed1999

An analysis of hospital-acquired bacteraemia in intensive care unit patients in a university hospital in Kuwait.

An analysis of hospital-acquired bacteraemia among ICU patients was carried out over a two-year period in order to determine the incidence, associated mortality rate and susceptibility pattern of causative pathogens. There was a high incidence of bacteraemia, occurring in 127 (18.4%) of 692 patients. Mortality attributable to nosocomial bacteraemia was 52% of the total 79 deaths from all causes. The highest mortality rate (58.5%) occurred in patients with fungal infections, whilst death from Gram-negative bacteraemia was only 17%. Over 98% of patients had underlying disease. Nearly half (46.8%) of 267 organisms isolated were Gram-positive. In comparison, Gram-negative bacteria accounted for 36.6% and the rest (17.6%) were fungi (mainly Candida albicans). The majority of the bactereamic episodes were monomicrobial (90.2%). Coagulase-negative staphylococci (CNS) were the commonest pathogens isolated, representing 32.6% of all organisms. Inducible beta-lactamase producing organism (Enterobacter spp. 9.7%, Serratia marcescens 6.7%, Klebsiella pneumoniae 6% and Pseudomonas aeruginosa 6%) formed the bulk of Gram-negative bacteria. In contrast, Escherichia coli (7.5%) and K. pneumoniae (4%) were the commonest Gram-negative bacteria from hospital-acquired bacteraemia in the general hospital population. The majority (80%) of CNS were resistant to methicillin (MRSE) but susceptible to vancomycin; they were relatively resistant to erythromycin, clindamycin and beta-lactams antibiotics. Whilst Gram-negative organisms were relatively susceptible to imipenem (85%), ciprofloxacin (88%) and amikacin (87%), they had unacceptably low levels of susceptibility to cefuroxime (59.3%), cefotaxime (71%), ceftazidime (60.9%), and piperacillin (51.1%). This study shows that hospital-acquired bacteraemia in ICU patients carries a poor prognosis. Information regarding the infective agents and their susceptibility in the ICU setting is valuable for the selection of empirical therapy before culture and susceptibility results are known.

Adolescent↗
PubMed1999

Enterotoxin production by coagulase-negative staphylococci in restaurant workers from Kuwait City may be a potential cause of food poisoning.

Staphylococcus aureus and coagulase-negative staphylococci (CNS) were isolated from the hands of food handlers in 50 restaurants in Kuwait City and studied for the production of staphylococcal enterotoxins, toxic shock syndrome toxin-1, slime and resistance to antimicrobial agents. One or a combination of staphylococcal enterotoxins A, B or C were produced by 6% of the isolates, with the majority producing enterotoxin B. Toxic shock syndrome toxin-1 was detected in c. 7% of the isolates; 47% produced slime. In all, 21% of the isolates were resistant to tetracycline and 11.2% were resistant to propamidine isethionate and mercuric chloride. There was no correlation between slime and toxin production or between slime production and antibiotic resistance. The detection of enterotoxigenic CNS on food handlers suggests that such strains may contribute to food poisoning if food is contaminated by them and held in conditions that allow their growth and elaboration of the enterotoxins. It is recommended that enterotoxigenic CNS should not be ignored when investigating suspected cases of staphylococcal food poisoning.

Anti-Bacterial Agents↗
PubMed1999

Detection of Mycobacterium tuberculosis complex and non-tuberculous mycobacteria by multiplex polymerase chain reactions.

The ability of two-band and three-band multiplex polymerase chain reactions to detect and differentiate Mycobacterium tuberculosis complex from non-tuberculous mycobacteria was evaluated. The polymerase chain reactions differentiated between M. tuberculosis and non-tuberculous mycobacteria when standard strains and clinical isolates of mycobacteria were tested. The sensitivity of the two-band and three-band techniques to detect M. tuberculosis in clinical specimens, compared with smear and/or culture, was 88% and 75% respectively. Although both techniques showed 100% specificity, the superior sensitivity of the two-band technique suggests that it could be more useful in the diagnosis of tuberculosis and in differentiating M. tuberculosis complex from non-tuberculous mycobacteria.

DNA, Bacterial↗
PubMed1998

Prevalence and susceptibility of Shigella species to 11 antibiotics in a Kuwait teaching hospital.

During the 5-year period 1990-1993 and 1996, 202 Shigella spp. were isolated from stool specimens of symptomatic patients of all age groups seen in our hospital. Over these periods the trend of the incidence of shigellosis showed that 18% of the total strains were isolated during the invasion year (1990) followed by an upsurge (24%) during the Gulf War period (1991) and a steady decline in the post-war period, 17% in 1992 and 14% in 1993. There was another wave of increased isolation rate (27%) during a period of relative calm in the country (1996) studied for comparison. The predominant Shigella species was S. flexneri which accounted for 46% of the 202 isolates, followed by S. sonnei (42%), S. dysenteriae (7%) and S. boydii (5%). Fifty-four percent of the 202 Shigella isolates were resistant to ampicillin, 56% to trimethoprim/sulfamethoxazole, 35% to chloramphenicol, 13% and 9% to cephalothin and amoxicillin/clavulanic acid respectively. All the isolates were fully susceptible to ciprofloxacin, the aminoglycosides and the second- and third-generation cephalosporins. Eighty-seven (43%) of the 202 isolates were resistant to two or more antibiotics. Of the 87 multiply resistant Shigella spp., 58 (67%) were S. flexneri while 19 (22%) were S. sonnei. Shigella resistance to the first-line antibiotics is a major problem that frequently limits the therapeutic options with orally available active antibiotic therapy.

Anti-Bacterial Agents↗
PubMed1998

Serogroups and antimicrobial susceptibility of clinical isolates of Salmonella species from a teaching hospital in Kuwait.

Salmonella strains isolated in a teaching-cum-general hospital in Kuwait during 1990-1993 and 1996 were analysed to determine the trend in the prevalence of the serogroups and their changing pattern of susceptibility. The records were reviewed for all the 661 isolates encountered during these periods. The most prevalent serogroup in both children and adults was serogroup B, followed by serogroup C and D. A sizeable proportion of the strains were resistant to first-line drugs. About 39% of the isolates were resistant to ampicillin, 17% to co-trimoxazole, 13% to chloramphenicol, and 15% to cephalothin. The majority were, however, susceptible to the other drugs with low to very low resistance rates: 7% to amoxicillin/clavulanic acid, and 0.3% to cefotaxime. All the strains were susceptible to ciprofloxacin. In all, resistant strains were more prevalent among children than adults.

Adult↗
PubMed1997

Nocardia asteroides in the soil of Kuwait.

A pilot study was undertaken to determine the occurrence and distribution of pathogenic nocardiae in Kuwaiti soil. A total of 102 soil samples collected from two localities were investigated by the paraffin bait technique. Nocardia asteroides was the only species isolated from 42 (41%) soil samples. None of the isolates fulfilled the criteria required for identification of N. farcinica or N. nova. Thirty one (73.8%) isolates showed equivalent growth at 45 degrees C and 35 degrees C, 17 (40.4%) isolates utilized acetamide for carbon and nitrogen requirements and 3 (7.1%) isolates showed delayed arylsulphatase activity. Only a solitary isolate was resistant to cefamandole. Soil samples originating from the Kuwait University Campus, Shuwaikh, which were rich in humus/organic matter, were more productive for N. asteroides (67%) than the samples which were devoid of it but were mixed with crude oil (39%). Sand samples that lacked organic matter and crude oil samples were least productive of N. asteroides. These preliminary findings do not suggest that massive oil contamination of soil in the Ahmadi oil field area during the Gulf war promoted the natural occurrence of N. asteroides. However, isolation of N. asteroides in as many as 41% of the soil sample is a significant observation warranting further epidemiologic studies including its possible role in the operation desert storm sickness syndrome. This is the first report on the natural occurrence of N. asteroides in Kuwait.

Fuel Oils↗
PubMed1997

Acute lower respiratory tract infections in children in Kuwait.

The features of community-acquired acute lower respiratory tract infections in 390 children are described. Half (50%) presented with bronchiolitis, 37% with pneumonia and 13% with croup. Respiratory syncytial virus was the commonest agent identified (52% of bronchiolitis, 29% of pneumonia, 51% of croup). Positive bacterial blood cultures were obtained in 10% of the patients, all except one with pneumonia. Fever (> 39 degrees C), a toxic ill look, bronchial breathing, WCC > 20 x 10(9)/l, neutrophils > 5 x 10(9)/l, platelet count > 500 x 10(9)/l, ESR > 45 mm/hr, lobar consolidation and pleural effusion were more likely to be associated with bacterial than with viral pneumonia (relative risk > 1.81; p < 0.05). In areas with limited resources, a high fever, a toxic ill look, bronchial breathing and simple laboratory tests may help to identify patients with bacterial pneumonia.

Acute Disease↗
PubMed1997

Identification of enteroinvasive Escherichia coli and Shigella strains in pediatric patients by an IpaC-specific enzyme-linked immunosorbent assay.

A new method, a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) recognizing a secreted, invasion plasmid-coded protein antigen (IpaC), was used to identify enteroinvasive Escherichia coli and Shigella strains among colonies from 859 cultures of fecal samples from children in Kuwait. A total of 33.8% of the samples were diarrheal. By the immunoassay, enteroinvasive E. coli strains were identified from two diarrheal samples but from none of the samples from children without diarrhea. These strains were fully virulent and belonged to serogroup O28ac. In addition, 26 Shigella strains were also recognized by the ELISA, while only 23 were isolated by routine biotyping and serotyping. For two diarrheal patients, Shigella was identified by culture only. The study showed that the IpaC-specific immunoassay is a simple and useful tool for identifying enteroinvasive strains. Furthermore, by reporting the first enteroinvasive E. coli isolates from Kuwait, the study indicates the presence of this group of pathogens as a potential source of diarrhea in the region.

Antigens, Bacterial↗
PubMed1996

Invasive fungal infections in renal transplant recipients.

In a retrospective analysis, 18 instances of invasive fungal infections were observed in 512 (3.5%) renal transplant recipients. These included candidiasis (8), aspergillosis (5), cryptococcosis (3) and zygomycosis (2). All patients with candidiasis had Candida isolated from blood and one or more additional sites. One of them had superadded fungaemia with Torulopsis glabrata. Pulmonary disease in four and subcutaneous infection in one were encountered in the five patients with aspergillosis. Central nervous system involvement in two and cutaneous lesion in one were the findings in patients with cryptococcosis. Zygomycosis involved the lung in one and the allograft itself in the other. Prolonged fever not responding to antibacterial drugs was the most common clinical presentation. Fungal infections occurred during the first 4 months in 10 (55.5%) and 12 to 108 months in eight (44.5%) patients. Infections with cytomegalovirus and hepatitis viruses were concommitantly present in 12 (66.7%) and eight (44.5%) patients respectively. Fourteen episodes of fungal infections (77.8%) occurred in live unrelated kidney recipients who formed only 48% of our total transplant population. Nine patients were treated with systemic and/or local amphotericin B and six with amBisome. Fluconazole was administered alone in three and in combination with amphotericin B in two. Fourteen patients died but mortality was only directly attributable to fungal infection in 11. We conclude that invasive fungal infections continue to be an important cause of morbidity and mortality in renal transplant recipients. A high index of suspicion. prompt diagnosis and early institution of specific antifungal therapy are needed.

Adult↗
PubMed1996

Nasal carriage of enterotoxin-producing Staphylococcus aureus among restaurant workers in Kuwait City.

Enterotoxin-producing Staphylococcus aureus is a common cause of staphylococcal food poisoning. To determine the incidence of carriage of enterotoxin-producing S. aureus in a sample of the healthy population in Kuwait city, restaurant workers in the city were screened for nasal carriage of S. aureus. 26.6% of 500 workers studied carried S. aureus and 86.6% of the S. aureus produced staphylococcal enterotoxins. 28% produced enterotoxin A, 28.5% produced enterotoxin B, 16.4% produced enterotoxin C and 3.5% produced enterotoxin D. Ten isolates produced both enterotoxins A and B or A and C. 73% of the isolates were untypeable with standard phages. However, 17.1%, 3% and 6% belonged to phage groups I, II and III respectively. The results demonstrated a high level of enterotoxigenic S. aureus carriage among restaurant workers which although lower than that reported for the general population and hospital workers may be important in the restaurant industry.

Bacteriophage Typing↗
PubMed1996

Molecular characterization of epidemic ciprofloxacin- and methicillin-resistant Staphylococcus aureus strains colonizing patients in an intensive care unit.

Eighteen methicillin-resistant Staphylococcus aureus (MRSA) samples isolated from patients and the environment in an intensive care unit (ICU) during a routine surveillance were tested for antimicrobial resistance and typed by pulsed-field gel electrophoresis. Three pulsed-field patterns were observed. Sixteen were ciprofloxacin resistant and had identical pulsed-field patterns. The results suggested that a ciprofloxacin-resistant MRSA clone had contaminated the environment and spread among patients. This study demonstrates the application of infection control surveillance combined with strain typing in detecting MRSA colonization in the ICU where it was not known to exist.

Anti-Infective Agents↗