Central venous catheter related infections in a tertiary care hospital.

Intravascular catheters are increasingly important causes of nosocomial infections. Catheter related complications range from local exit site or tunnel infections to frank bacteremias. A semiquantitative method of culture of central venous catheters (CVC) was done in our hospital from January to December 1996. A total of 119 catheter tips sent to the Microbiology Department were cultured and 11 (9.24%) showed significant growth with associated blood stream infection. 14 (11.76%) of the CVCs showed scanty or less than 15 colonies in roll or contents and there was no associated blood stream infection. 7 (5.88%) showed moderate to heavy growth in roll and contents and there was no blood stream infection. The age groups ranged from 2 months to 66 years. The results of the study indicate that Gram negative organisms formed the predominant isolates. Gram negative isolates included Klebsiella species, Enterobacter species, E. coli species, Serratia and non-fermenting Gram negative bacilli. Coagulase negative staphylococcus which is often believed to be an important pathogen was not associated with bacteremia or septicemia in our hospital, during this study period. Considering the fact that 1553 operations were performed during the study period, the infection rate through CVC's would work out to a negligible 0.71%.

Aspergillus terreus, an uncommon fungus causing aortic root abscess and pseudoaneurysm.

Aspergillus Terreus is a rare fungus which can cause opportunistic infection in humans. A fifteen year old girl had undergone open aortic valvotomy for aortic stenosis and post-stenotic dilatation of the ascending aorta. She was discharged after an uneventful post-operative period. She was reoperated later for para-aortic abscess. The pus on culture yielded pure growth of Aspergillus Terreus from multiple media. To our knowledge, this is the first report from India of Aspergillus Terreus causing human infection. Clinical awareness of the rising importance of fungal infections is alerted.

Long-term preservation of streptococci.

Strains of 12 T types of group A streptococci preserved by sand desiccation and stored at 4 degrees to 10 degrees C were regularly sub-cultured to check their viability. For this, streptococci coated onto sand particles mixed with sterile sheep blood were inoculated into Todd-Hewitt broth with added blood and incubated for 24 to 48 h. Checking for viability every six months showed that group A streptococci could be preserved by this method for 21 yr. Our study shows that sand desiccation is a convenient and cheap method for the long-term preservation of streptococci in laboratories where other methods of preservation are not feasible on a regular basis.

Cutaneous lymphatic sporotrichosis.

The first case of cutaneous lymphatic sporotrichosis from Nagaland and a case of cutaneous sporotrichosis from Kerala who had acquired infection from Assam are reported. The diagnosis in both cases were established by isolating Sporothrix schenckii from multiple cutaneous lesions. The dimorphic nature of fungus was established in vitro by demonstrating the mycelial phase at 25-30 degrees C and yeast phase at 37 degrees C and pathogenicity to white mice. Both the patients were successfully treated with oral administration of potassium iodide for 3 months.

Fallacies in the interpretation of Paul-Bunnel Davidsohn differential test.

Serological findings in five cases where Paul-Bunnel Davidsohn (PBD) test results were misleading, are presented. Three patients' with Chronic renal disorder and positive PBD test had specific serology results, signifying Cyto Megalo Virus infection. A fourth patient with Hepatitis B Virus infection also had positive PBD test. Forssman type of antibody response was demonstrable in a boy with recent Epstein-Barr virus infection and high Cyto Megalo Virus antibody titres.

Non 01 Vibrio cholerae in intestinal and extra intestinal infections in Vellore, S. India.

Non 01 V.cholerae is known to cause gastroenteritis and extra intestinal manifestations, including septicemia. We report here our isolation of non 01 V.cholerae from various clinical specimens. Although most of the isolates are from faeces samples from patients with diarrhoea, we have three isolates from blood culture in patients with underlying liver disease. The highest incidence occurred in 1982-1983 and 1987 and 1988.

Aeromonas species in human septicaemia & diarrhoea.

An increase was observed in the isolation of Aeromonas sp. from clinical specimens, especially faeces, from patients with diarrhoeal disease and blood cultures from patients with suspected septicaemias. The isolation rate from diarrhoeal patients was 0.2 per cent in 1978-79 and this increased to 5.0 per cent in 1986-87. It is noteworthy that 13 patients of septicaemia due to Aeromonas species were encountered, predominantly in adults with lowered resistance due to underlying disease states including chronic diseases of the liver and kidney.

Transferable trimethoprim resistance of shigellae encountered in Vellore (south India).

Shigella flexneri and Sh. shigae which are the two most common shigellae encountered in Vellore (south India) were found to exhibit resistance to trimethoprim and trimethoprim-sulphamethoxazole. Eighty four per cent of this was high level resistance. Transfer studies conducted with these strains indicated that this high level resistance is plasmid mediated.

Speciation of viridans streptococci & their significance in human infections.

Sixty strains of viridans streptococci recovered, from various infections, encountered in a large referral Hospital in Tamil Nadu (south India) from December 1983 to May 1985 were characterised by conventional tests. Of these, 57 (95%) belonged to four species viz., Sanguis II, Mitis, Intermedius and Constellatus. Of the 40 strains that were assessed for their clinical significance, 23 (57.5%) were found to be either significant or of suggestive significance. The study suggested viridans streptococci are not particularly virulent pathogens. But local/systemic factors were found to predispose the subjects to this infection.