Evaluation of different tests for detection of Staphylococcus aureus using coagulase (coa) gene PCR as the gold standard.

A total of 288 staphylococcal specimens isolated from different clinical specimens were selected for the evaluation of tests used to detect Staphylococcus aureus. The coagulase (coa) gene PCR was preformed, which confirmed 288 specimens as S. aureus and 51 specimens as coagulase negative staphylococci (CONS). All the specimens were subjected to slide coagulase test, Slidex Staph plus test and tube coagulase test. Sensitivity, specificity, positive predictive value and negative predictive values of were calculated using coa gene PCR as gold standard for the detection ofS. aureus. The tube coagulase test showed very good sensitivity (98.7%), specificity (98.1%), PPV (99.5%) and NPV (94.4%) than other methods. Slidex Staph plus test showed fairly good sensitivity and specificity. Slide coagulase test has good specificity but poor sensitivity. Therefore we recommend that tube coagulase test be done routinely for the detection ofS. aureus in microbiology laboratory.

Studies on the residues of terramycin and furazolidone in broiler meat--a public health concern.

The concentration of Terramycin and Furazolidone residues in broiler meat following their subtherapeutic use in the ration of the birds were detected as 296 ng/g, 174 ng/g, 40 ng/g, 60 ng/g and 124 ng/ml in kidney, liver, thigh muscle, breast muscle and serum for Terramycin and 270 ng/g 160 ng/g and 88 ng/ml in kidney, liver and serum for Furazolidone. One week of withdrawal period from the antibiotic in feed/water was sufficient to render the meat free from residues.

Staphylococcal zoonosis on dairy farms in Assam and Meghalaya.

OBJECTIVE: To assess if Staphylococcus aureus is transmitted between man and animals & vice-versa. METHODS: Staphylococcus aureus belonging to biotype C (bovine origin) were isolated from nares and hands of workers on six dairy farms of Assam and Meghalaya. The cows on the farms had a high rate of prevalence of mastitis caused by the same biotype of S. aureus. Three strains of S. aureus biotype A (human origin) were isolated from mastitis milk samples from cows on one of these farms, in which one of the workers was having cuteneous lesions (crusty abscess) and one strain of S. aureus biotype A was isolated from a swab sample collected from an abscess on the skin of the worker. RESULTS: It has been revealed that all the members of the workers family were suffering from a similar type of cuteneous infection, indicating that it was a case of impetigo. The antibiotic susceptibility pattern of all the three biotype A strains from bovine origin was identical to that of the biotype A strains isolated from the worker. The percentage of resistance to 12 commonly used therapeutic antimicrobial agents was higher among the biotype C strains from human origin than the biotype C strains from bovine origin. Several strains from cattle and human origins showed identical antimicrobial susceptibility patterns against the tested agents.

Incidence and risk factors of retinopathy of prematurity in a tertiary care newborn unit in New Delhi.

BACKGROUND: Retinopathy of prematurity (RoP) has become more common in developed countries with an improvement in survival of very premature infants. Though previously rare, it is likely to emerge as a major problem in India because of improving outcome of 'at-risk' preterm infants. METHODS: In a prospective study we estimated the incidence of RoP among at-risk neonates in a tertiary care unit. Infants with birth-weights of < 1500 g, gestation < 35 weeks and preterm neonates who required supplemental oxygen for > 24 hours were subjected to periodic ophthalmological evaluation for detection of RoP until full retinal vascularization occurred. RESULTS: Sixty-six eligible infants completed the full protocol during the 15-month study period. The incidence of RoP was 20% in the cohort and 27% among the very low birth-weight neonates. The incidence of threshold RoP was 7% in the cohort. The occurrence of RoP was inversely related to the gestation and birth-weight. RoP typically developed at the post-conceptional age of 32-35 weeks. Blood transfusion and clinical sepsis emerged as independent risk factors of RoP on step-wise logistic regression analysis. Cryotherapy undertaken in 5 cases (9 eyes) led to amelioration of the changes of RoP. CONCLUSION: The incidence of RoP in our neonates was lower than that reported from other centres. Blood transfusion and clinical sepsis are risk factors for RoP in our newborn infants.

Anti-insulin antibodies and retinopathy in juvenile onset type-1 diabetes.

Juvenile diabetics have severe loss of beta cell function and require replacement therapy with insulin. Insulin antigenicity can produce anti-insulin antibodies resulting in allergic reactions and insulin resistance. The role of insulin-anti-insulin antibody complexes in the development and progress of chronic diabetic complications like microangiopathy is not very clear. In the present study, there was statistically a significant trend of higher insulin antibody binding levels in IDDM patients who developed retinopathy. Though there was a trend of higher insulin antibody in IDDM patients with retinopathy, there was no association between insulin antibody and HLA antigen which some authors have reported.

Genetic marker in juvenile diabetic retinopathy.

Thirty five patients with insulin dependent diabetes mellitus (IDDM) were investigated for development of retinal microangiopathy by fluorescein angiography. HLA typing (A,B.C antigens) was done as a genetic marker. There was no statistically significant difference in the frequency of HLA antigens between patients without retinopathy (Gr.I) and with retinopathy (Gr.II) Frequency of various HLA antigens did not differ significantly in the mild and severe retinopathy groups or in comparison with controls. HLA B8 was significantly over represented in the patients of IDDM as a single group (GrI + II) when compared with controls (26% vs 8%). HLA profile was not a predictor of either the development or the severity of retinopathy in IDDM.