Polymerase chain reaction based diagnosis of systemic fungal infections and sensitivity testing of the fungal isolates.

PURPOSE: To highlight the usefulness of polymerase chain reaction (PCR) for the rapid diagnosis of systemic fungal infections. METHODS: Clinical samples were collected from 50 clinically suspected cases of systemic mycosis and subjected to smear, culture, antifungal sensitivity and PCR (based on 18S rRNA gene). RESULTS: Of the 50 clinical specimens tested by PCR, 39 were found to be positive. PCR gave more positive results than smear and culture examination. Out of the 50 clinical specimens 35 were found to be fungal culture positive. The sensitivity testing results of these fungal isolates showed that there was a good correlation between the in vitro results and the clinical response of the patient to antifungal therapy. Itraconazole exhibited maximum antifungal activity followed by fluconazole, ketoconazole and amphotericin B. CONCLUSIONS: PCR technology provides rapid and accurate diagnosis of fungal infection, however, it must be used with caution to avoid false positives.

Cryptococcal meningitis in AIDS.

A study was carried out to determine the incidence of Cryptococcus species in AIDS patients and their susceptibility pattern to the different antifungal drugs used for therapy. PCR as a rapid diagnostic tool for cryptococcal meningitis was evaluated. All the isolates were senstive to the three antifungal drugs tested indicating that the development of drug resistance is not a major problem in the treatment of cryptococcosis. All the culture positive specimens were positive by PCR which can be evolved into a very useful, rapid diagnostic tool to detect cryptococci in clinical specimens.

Human immunodeficiency viruses types 1 and 2 infection among replacement blood donors in Mumbai (Bombay).

Between 1993-96, blood donated by 12,235 replacement blood donors was screened by various Enzyme Linked Immunosorbent Assays for detecting antibodies to Human Immunodeficiency Viruses types 1 and 2 according to the guidelines specified by Indian--Food and Drug Administration. 222 replacement blood donors (1.81%) were found to be seropositive for antibodies to Human Immunodeficiency Virus types 1 and 2. Furthermore, the ImmunoComb II HIV 1 & 2 BiSpot rapid sandwich ELISA in a comb format was used for differentially identifying HIV-1 and/or HIV-2 infection among these blood donors in Mumbai. Our data indicates that there is a low seroprevalence of HIV-1-2 infection among replacement blood donors in Mumbai (Bombay). Among them, while HIV-1 is still the predominant virus, dual HIV-1-2 and HIV-2 only infections are steadily increasing.

Increasing prevalence of HIV-2 and dual HIV-1-2 infections among patients attending various outdoor patient departments in Mumbai (Bombay).

Between 1993-96, a serological study was carried out for differentially identifying HIV-1 and HIV-2 infections among the high risk group persons attending the various outdoor patient departments of BYL Nair Municipal Hospital, Mumbai. This study indicates that although HIV-1 is still the predominant virus among the high risk HIV infected persons in Mumbai, dual HIV-1-2 infections are increasing especially among promiscuous heterosexuals and female commercial sex workers. Increases in HIV-2 infections were observed later than dual HIV-1-2 infections, indicating that it is the HIV-1 infected individuals who through continued high risk behavior got infected by HIV-2.

Importance of autopsy in prevention of epidemics.

With resurgence of infectious diseases all over the globe, there is need for constant surveillance and specially trained staff to expertly carry out autopsies on suspected cases and determine the exact cause of death. Early and accurate diagnosis is important in order to prevent worldwide spread of the disease.

Allergy diagnosis by Pharmacia Cap System.

From September 1995 to September 1998, sera from 959 suspected allergy patients have been tested by the new Pharmacia Cap System. Of these, 80 per cent were diagnosed to suffer from some allergy while 20 per cent reacted negative. It was found that the CAP system gave accurate and clear cut results to the satisfaction of the patient and referring physician.

Multidrug resistant Salmonella.

A total of 326 salmonella strains was isolated and studied from suspected enteric fever cases in Mumbai (Bombay) during a 2 year period from May 1992 to July 1994. These were identified using standard biochemical and serological tests. Bacteriophage typing, antibiotic sensitivity and conjugation experiments were also carried out. S. typhi was the most common serotype accounting for 75.46% of the strains. Among S. typhi strains 87% were biotype I and 13% were biotype II. 9.5% strains were of S. paratyphi A, 5.52% of S. typhimurium, 4.60% of S. worthington, 4.30% of S. havana and 0.62% of S. enteritidis. The commonest bacteriophage type of S. typhi was E1, and of S. paratyphi A type 1, whereas 88.88% strains of S. typhimurium were untypable. Most of the strains were multidrug resistant including commonly used antibiotics such as chloramphemicol, ampicillin, and cotrimaxazole. Quinolone derivatives such as Ciprofloxacin were found to be the most effective drugs. In the conjugation experiments there was direct transfer of resistance pattern and enbloc transfer of resistance was observed in most strains. Salmonella typhi is still the most commonly encountered species. There is an alarming increase in multidrug resistance.

Enzymes--a review.

Enzymes are essential to life and catalyze various metabolic activities. They find application in a number of diseased conditions, and their scope is being widened as knowledge develops.

New vaccines for disease prevention.

New vaccines are needed for the control of some existing as well as other new or emerging diseases. In the long run they can be made cost-effective with the application of modern methods of biotechnology and would thus save considerable expense and hardship suffered at present by mankind.