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Biomedical subjects

R Chaudhry

Publications and source records attributed to R Chaudhry.

At least 19 recordsLinked to original sources
PubMed2006

Incidence and characterization of Clostridium perfringens isolated from antibiotic-associated diarrhoeal patients: a prospective study in an Indian hospital.

Clostridium perfringens has been reported as causing between 2-15% of all cases of antibiotic-associated diarrhoea (AAD), and may be diagnosed by detection of enterotoxin in faeces. A prospective study comprising 150 diarrhoeal patients and 100 non-diarrhoeal controls was undertaken to assess the incidence of C. perfringens-associated diarrhoea in an Indian hospital. Methods used included C. perfringens culture, reverse passive latex agglutination (RPLA) and enzyme-linked immunosorbent assay (ELISA) for detection of enterotoxin, and polymerase chain reaction (PCR) assay for the presence of enterotoxin gene. Attempts were made to type the isolates by multiplex PCR. Of the 150 diarrhoeal stool samples tested, 13 were culture positive. Of these, four were positive for C. perfringens enterotoxin by RPLA, two were positive by PCR and two were positive by RPLA and ELISA. Twenty-seven samples were positive for culture of C. perfringens in non-diarrhoeal controls but none were positive for enterotoxin either by RPLA or by PCR. The average incidence of C. perfringens AAD using these methods was 2.6%. Toxin typing showed that all the isolates belonged to type A. To conclude, the relatively low incidence of toxigenic C. perfringens suggests that enterotoxigenic C. perfringens is not a major cause of AAD in this population.

Adolescent↗
PubMed2005

Formulation and evaluation of an effective pH balanced topical antimicrobial product containing tea tree oil.

The effect of pH on the antimicrobial activity of Melaleuca alternifolia essential oil formulations was studied. Microemulsions, liposomal dispersions, multiple emulsions and a colloidal bed of sterile clay were formulated using 5% w/w of tea tree oil. A number of formulations were prepared at various pH values (5.0, 5.5, 6.0, 6.5, and 7.0). Thermal stability studies showed that the formulations were stable for more than eight months. Agar dilution tests showed MICs of 1.0% v/v S. aureus and S. epidermidis. In the broth dilution test, MBC of the oil for P. acnes was 0.5% v/v. MIC and MBC values were comparable to those of non-formulated tea tree oil, indicating that tea tree oil retained its activity in the above-mentioned formulations. The microbiological evaluation showed that the formulations containing 5% w/w tea tree oil had a maximum effect at pH 5.5.

Acne Vulgaris↗
PubMed2004

Radiation related morbidities and their impact on quality of life in head and neck cancer patients receiving radical radiotherapy.

Although 50-70% of head and neck cancer patients in India receive radiotherapy (RT), radiation-related acute and late morbidities and their impact on quality of life (QOL) are infrequently reported. Acute and late radiation morbidities and QOL were assessed in a prospective longitudinal study of 45 patients with head and neck cancers receiving radical RT to a dose of 7000 cGy in conventional fractionation. Grade II acute morbidities experienced by the largest percent of the sample during the course of RT pertained to the mucosa (66.4%), salivary gland (84%), and oesophagus (53%). These morbidities led to an increase in the symptom scores of appetite loss (76.46), fatigue (65.75) and pain (44.77). This increase in the symptom scores consequently led to a significant decline in physical, social and emotional functioning as well as global health status score during the course of RT (p < 0.001). Scores improved after 1 month of RT but did not reach the pre-RT value. Future studies may consider correlating QOL assessment to significant patient and disease related parameters such as performance status, weight loss, stage and site of disease.

Adult↗
PubMed2004

Reduced susceptibility to ciprofloxacin and gyra gene mutation in North Indian strains of Salmonella enterica serotype Typhi and serotype Paratyphi A.

The emergence of reduced susceptibility to ciprofloxacin among Salmonella enterica serotype Typhi and serotype Paratyphi A leading to clinical failure of treatment poses a great therapeutic challenge. The mechanism of fluoroquinolone resistance in clinical isolates of S. Typhi and S. Paratyphi A is not very well documented. The present study was carried out with the objective of molecular characterization of reduced quinolone susceptibility amongst the strains of S. Typhi and S. Paratyphi A isolated from the patients with enteric fever during January, 2000, to April, 2003, in a North Indian hospital. A total of 422 culture-positive cases of enteric fever were reported to the hospital during the period of study, of which S. Typhi was isolated from 350 cases and S. Paratyphi A from 72 cases. The antimicrobial susceptibility of these strains was determined by disk diffusion and agar dilution method according to NCCLS guidelines, and E-test method. A total of 140 randomly selected strains, isolated during the years 1993-1999, that were available from the laboratory stocks were also studied to compare with the present strains. To study the quinolone susceptibility, the strains were divided into nalidixic acid sensitive (NAS), nalidixic acid intermediate resistant, (NAI) and nalidixic acid resistant (NAR) on the basis of susceptibility to nalidixic acid. Clinical history was available from 174 patients, of which 93 needed hospitalization due to severe disease. Of these, 82 patients were infected with NAR strains and 22 patients had a documented evidence of clinical failure to ciprofloxacin therapy. The patients infected with NAR strains were younger and had a significantly longer duration of fever (p value < 0.05) than those infected with NAS strains. It was observed that the proportion of NAR strains increased gradually over the years. These strains had a significantly higher range of MIC of ciprofloxacin (0.023-1.0 microg/ml) as compared to the NAS strains (0.002-0.125 microg/ml) (p value < 0.05). The sequencing of quinolone resistance determining region (QRDR) of the gyrA gene showed the presence of mutation at either Ser 83 or at Asp 87 in all the NAR and NAI strains. None of the NAS strains had a mutation, suggesting that the gyrA gene mutation is sufficient to confer resistance to nalidixic acid and reduced susceptibility to ciprofloxacin. This mutation, although phenotypically expressed as decreased susceptibility to ciprofloxacin, goes undetected by the disk diffusion method using the present NCCLS guidelines. Hence, it can increase morbidity and mortality due to delay in appropriate antibiotic treatment.

Adolescent↗
PubMed2003

Effect of dental films containing amoxycillin and metronidazole on periodontal pathogens: microbiological response.

Biodegradable dental films containing a combination of amoxycillin and metronidazole were prepared by a dispersion method. The aim of the present study was to determine the antimicrobial activity of this formulation against the pathogens which are commonly implicated in periodontal infections. Films showed sustained release in vitro for a period of 16 days. In situ release studies carried out using fresh bovine buccal mucosa in a flow through cell, showed that drug concentrations were maintained above MIC values for the entire period of the release studies. Samples from these studies were capable of inhibiting the growth of most of the test strains. The combination of amoxycillin and metronidazole using carrier polymer poly-L (lactide co-glycolide) not only showed an extended spectrum of antimicrobial activity but also showed a synergistic effect against Eubacterium limosum, which had earlier been reported resistant to metronidazole.

Absorbable Implants↗
PubMed2002

Genetic diversity of Salmonella enterica serovar Paratyphi A from different geographical regions in Asia.

AIMS: Subtyping of Salmonella Paratyphi A isolates from India, Pakistan, Indonesia and Malaysia was carried out by pulsed-field gel electrophoresis (PFGE) to assess the extent of genetic diversity of these isolates from different endemic countries. METHODS AND RESULTS: A total of 39 human isolates of Salmonella Paratyphi A from Pakistan, India, Indonesia and Malaysia were studied using PFGE analysis following digestion of chromosomal DNA with XbaI. Seven isolates from Pakistan were resistant to ampicillin, tetracycline and cotrimoxazole. It was noted that Salmonella Paratyphi A isolates obtained from outbreaks in India had limited genetic diversity and probably belonged to closely related clones. Significant genetic homogeneity was observed among antimicrobial-resistant isolates from Pakistan and antimicrobial-sensitive isolates from Pakistan and Indonesia, respectively. CONCLUSIONS: PFGE was a useful subtyping technique to differentiate Salmonella Paratyphi A from different endemic countries. However, it fails to differentiate the antimicrobial-resistant and -sensitive strains. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of the present study verify the usefulness of PFGE in characterizing and comparing strains of Salmonella Paratyphi A. Our study suggests that a limited number of clones are responsible for paratyphoid fever in these countries.

Asia↗
PubMed2002

A study of bacteremia in febrile neutropenic patients at a tertiary-care hospital with special reference to anaerobes.

Patients with hematological malignancies who are receiving chemotherapy suffer prolonged periods of neutropenia, which leads to a greater risk of infection and mortality. A prospective study was conduced to determine the incidence of bacteremia in patients of hematological malignancies over a 2-yr period. A total of 119 episodes of febrile neutropenia occurred among 96 consecutive patients, of which 35 episodes were associated with bacteremia. Forty-four percent of the isolated bacteria were Gram-positive aerobes and 46% were Gram-negative aerobes. Staphylococcus aureus, Enterococcus spp., and Escherichia coli were the most common isolates. Gram-negative bacteremia was associated with a higher mortality. Anaerobes accounted for 4.4% of all isolates. The episodes of anaerobic bacteremia were polymicrobial and had a fatal outcome. A high incidence of antimicrobial resistance among aerobic and anaerobic bacteria was also recorded. Compared to previous years, a shift from a predominating Gram-negative to a Gram-positive etiology was noted. The initial empiric antibiotic regimens should be based on a local knowledge of the most common causative microorganisms, their sensitivity pattern, and the outcome of bacteremia.

Adolescent↗
PubMed2001

Breast cancer survival by teaching status of the initial treating hospital.

BACKGROUND: A number of studies have documented variation in treatment patterns by treatment setting or by region. In order to better understand how treatment setting might affect survival, we compared the survival outcomes of women with node-negative breast cancer who were initially treated at teaching hospitals with those of women initially treated at community hospitals. METHODS: We constructed a retrospective cohort consisting of a random sample of 938 cases, initially diagnosed in 1991, drawn from the Ontario Cancer Registry. Exposure was defined by the type of hospital in which the initial breast cancer surgery was performed. Outcomes were ascertained through follow-up of vital statistics. RESULTS: The crude 5-year survival rate was 88.7% for women who had their initial surgery in a community hospital and 92.5% for women who had their initial surgery in a teaching hospital. Women in higher income neighbourhoods experienced better survival at 5 years regardless of which type of hospital they were treated in. Multivariate proportional hazards regression modelling demonstrated a 53% relative reduction in risk of death among women with tumours less than or equal to 20 mm in diameter who were treated at a teaching hospital (relative risk [RR] = 0.47, 95% confidence interval [CI] 0.23-0.96), whereas among those with larger tumours there was no demonstrated difference in survival (RR = 1.32, 95% CI 0.73-2.32). Other variables that were significant in the model were age at diagnosis, estrogen receptor status and the use of radiation therapy. INTERPRETATION: Women with node-negative breast cancer and tumours less than or equal to 20 mm in diameter who were initially seen at a teaching hospital had significantly better survival than women with similar tumours who were initially seen at a community hospital. Survival among women with larger tumours was not statistically significantly different for the 2 types of hospital.

Actuarial Analysis↗
PubMed2001

Infections caused by Gemella spp.: case reports from India.

Human infections caused by Gemella spp. are rare. We report here our experience of the isolation of species of Gemellae from various clinical samples. Careful and complete identification of this organism will prevent diagnostic and therapeutic delays and bring more such cases to light.

Adult↗
PubMed2001

Infective complications of central venous catheters in cardiac surgical patients.

Prospective randomised study was conducted over a 24 months period in a cardiac surgical intensive care unit to determine the incidence of infection associated with multilumen venous catheters. The influence of various factors including fever, peripheral blood culture, catheter site, catheter usage for monitoring central venous pressure and/inotrope therapy on infection rates were statistically evaluated. A total of 100 catheters submitted to the Microbiology laboratory were bacteriologically examined. Forty-nine of these were inserted into upper body sites, and 51 were inserted into the femoral vein. Twenty-one were triple-lumen catheters. Catheters were removed when a central line was no longer necessary. Catheter tips were cultured by semiquantitative technique for aerobic and anaerobic bacteria. Bacteremia occurred in 3% of catheter insertions; (Enterococcus faecalis, one; Enterobacter spp. One; Acinetobacter spp., one); and catheter colonisation developed in 24%. Neither catheter colonisation nor catheter related infection were associated with any of the risk factors evaluated. Our data indicates that central venous catheters are safe to use in our patients. The inability to identify "risk factors" for catheter infection emphasise the need to maintain a high index of suspicion.

Adolescent↗
PubMed2000

Acute respiratory tract infections in Indian children with special reference to Mycoplasma pneumoniae.

A total of 70 Indian children of either sex and under 5 years of age who were admitted to the All India Institute of Medical Sciences, New Delhi during a 1-year period (January 1994-December 1994) with complaints suggestive of acute respiratory tract infections (ARTI), were investigated for bacterial aetiology of infection with special reference to Mycoplasma pneumoniae. Microbial aetiology could be established in 44/70 (62.8 per cent) of cases of ARTI. Mycoplasma pneumoniae infection was seen in 21/70 (30 per cent), aerobic bacteria in 14/70 (20 per cent), Chlamydia pneumoniae in 2/70 (2.8 per cent), and mixed infection with mycoplasma either with bacteria and/or chlamydia in 7/70 (10 per cent). However, in 26/70 (37.1 per cent) cases no cause could be detected. Diagnosis of infection with M.pneumoniae was based on culture in 2/20 (10 per cent) cases, antigen detection in throat swab by indirect immunofluorescence assay using specific antibody in 16/70 (22.8 per cent) cases, and demonstration of IgM antibody in serum by serodia Myco II particle agglutination test in 17/70 (24.2 per cent). Streptococcus pneumoniae (9/70, 12.8 per cent) and Staphylococcus aureus (5/70, 7.1 per cent) were the aerobic isolates from blood in these patients. Results of this study indicate that M.pneumoniae plays a significant role in respiratory tract infection in an Indian paediatric population. Rapid diagnostic procedures, such as antigen detection and IgM antibody demonstration, should be used more widely to determine the infective aetiology early in the course of illness. The study also highlights the mixed aetiology in ARTI in children, which has important therapeutic implications.

Antibodies, Bacterial↗
PubMed2000

The incidence of Legionella pneumophila: a prospective study in a tertiary care hospital in India.

The prevalence of Legionella pneumophila causing community-acquired pneumonia (CAP) in patients who were admitted to hospital was investigated. Between April 1997 and December 1998, 60 patients admitted to the All India Institute of Medical Sciences with CAP, were included in the study. Aetiological diagnosis was based on the results of routine microbiological blood culture for bacteria and serological test by enzyme linked immunosorbent assay (ELISA) for L. pneumophila serogroup 1-7. Eight (13%) patients had a conventional bacterial aetiology and nine (15%) had serological evidence of recent infection with L. pneumophila. Legionella pneumophila may be an important cause of CAP in adults in developing countries. Empiric antimicrobial treatment should include a combination of agents to cover both atypical agents and bacterial pathogens.

Adult↗
PubMed2000

Busy physicians and preventive services for adults.

OBJECTIVE: To study the relationship between overall productivity and the rates at which primary care physicians, in a fee-for-service setting, deliver or prescribe preventive services to adult patients. PATIENTS AND METHODS: The charts of 452 adult patients treated by 8 family practitioners and 5 internists in a fee-for-service practice setting were randomly selected and abstracted for provision of 10 preventive services over a 27-month period. The percentage of eligible patients screened for each service was correlated with the production of each physician measured in relative value units (RVUs). RESULTS: The correlation coefficient between RVUs and the aggregate of the 10 services was 0.23 (95% confidence interval [CI], -0.36 to 0.70). The individual correlation coefficients between RVUs and 9 of the 10 preventive services ranged from -0.05 to 0.43. For cervical cancer screening, however, the correlation coefficient was -0.72 (95% CI, -0.91 to -0.24). CONCLUSION: With the exception of screening for cervical cancer, the data presented in this study do little to support physicians' common belief that lack of time is the reason they are unable to incorporate prevention strategies into their clinical practice.

Adult↗