 |
       |
|
|
ABSTRACTS OF PAPERS AT THE 76TH RESEARCH MEETING OF THE MEDICAL RESEARCH CENTRE OF BOMBAY HOSPITAL ON MONDAY, 10TH APRIL 2000, 2.30 PM, SP JAIN CAFETERIA (CONVENOR DR. HL DHAR)
1. RAPID DIAGNOSIS OF CRYPTOCOCCAL MENINGITIS
Lina Deodhar, Sweta Chomal, Priya Miskeen
Disseminated cryptococcosis is becoming a common clinical entity in patients with Acquired Immuno Deficiency Syndrome (AIDS) and, meningitis occurs in approximately two thirds of patients with disseminated infections. The causative agent is the yeast fungus called Cryptococcus neoformans (C. neoformans). The fungus measures 4-20 micrometers in diameter and has a slimy polysaccharide capsule. The capsular antigen diffuses into the spinal fluid and blood, and hence, can be detected by a serological test called, latex agglutination test (Crypto LA test).Cultural and histological procedures for demonstration of C. neoformans, can take a long time. The capsule of C. neoformans can be demonstrated by negative staining (India ink). However, the sensitivity of negative staining procedure is 40-50 per cent in patients who are not infected with Human Immunodeficiency virus (HIV); whereas, the direct detection of the antigen in CSF or blood has a sensitivity of 90-100 per cent. The India ink test appears to have greater sensitivity in patients, who are infected with HIV.
In the patients who are HIV negative, immunosuppressive therapy or disease is a risk factor for cryptococcosis.
In two years period, 402 cerebrospinal fluid samples (CSF) were received for cryptococcal LA test. The test kit supplied by Fumose, France, was used and the tests were done according to the manufacturer’s instructions. Quantitative studies were done, whenever asked for India ink studies were done on all CSF samples. Several samples were referred from peripheral hospitals. Clinical history, laboratory findings, and treatment was noted down. 54 CSF samples gave Crypto LA test positive. Out of these, 31 patients were HIV seropositive. In a few patients, after the treatment with antifungal drugs, the titre of Crypto LA test was found to be decreased.
2. STUDIES ON THE INCIDENCE, TYPING, AND DRUG RESISTANCE OF ENTEROCOCCI, FROM URINARY TRACT INFECTIONS
Lina Deodhar, Priya Miskeen
Emerging problem pathogens and increase in drug resistance pose a big challenge to clinicians. Hospitals struggle with a number of important disease causing organisms; i.e., methicillin resistant Staphylococcus aureus, vancomycin resistant Enterococcus, multidrug resistant Enterobacter, and Pseudomonas aeruginosa etc.Enterococci have been documented as significant agents of urinary tract infections (UTI) particularly in hospitalised patients. In the Centers for Disease Control (CDC) - report on nosocomial infections, in 1984, enterococci were listed as the third most common causative agents of urinary tract infections, causing 14.7% of UTI. In one study from veterans administration hospital, enterococci were found in 21% of cases of UTI. The rate of colonisation and causation of infection of the urinary tract by enterococci is higher in patients who had a history of recurrent UTI’s and in patients who received antibiotics, to which enterococci are known to be intrinsically resistant. Enterococci may also be implicated in cases with prostatitis and perinephric abscesses.
A combination of penicillin or ampicillin, and an aminoglycoside is the treatment of choice in these infections. However, in cases in which, a beta-lactam antibiotic cannot be administered because of its intolerance, or due to resistance, vancomycin, in combination with aminoglycosides is the recommended regimen. It is therefore of concern that, in addition to the known cases of beta - lactam and aminoglycoside resistance, there have been several reports on emergence of vancomycin resistance in these organisms.
The present study was undertaken with a view at characterising the clinical isolates of enterococci, recovered from cases of UTI, in a hospital environment, on the basis of their morphological and physiological behaviour.
In a one and a half year period, a total of 4030 samples of urine and 780 urinary catheter tip specimens were studied bacteriologically. Out of these, 1990 urine specimens and 561 catheter tips yielded bacterial growth in culture. Among these enterococcal organisms were isolated in pure cultures from 147 urine and 73 urinary catheter tip specimens. Of the 73 cases of urinary catheter tip involvement, 33 cases yielded a pure growth of enterococci in urine cultures as well.
Enterococcus faecalis was the most predominant species, followed by Enterococcus faecium and Enterococcus durans. Vancomycin, teicoplanin, and nitrofurantoin were the drugs of choice, to which the organisms exhibited no resistance. The extent of resistance to penicillin and ampicillin was 23.13%. High level aminoglycoside (gentamicin, and streptomycin) resistance was observed in 35.38% of the enterococcal isolates studied.
MICs of the three antibiotics, ampicillin, vancomycin and teicoplanin were determined by first performing the conventional method of agar dilution. The results observed were then compared with those obtained by the E-test method (A.B biodisc, Sweden). The results of the two MIC detection methods were found to be comparable.
3. SIGNIFICANCE OF PANEL REACTIVE ANTIBODIES IN SUCCESSFUL RENAL TRANSPLANTATION
S R Kankonkar, S P Trivedi, S J Tijoriwala, S C Raikar, R V Prabhu
Human leucocytes antigens (HLA) Specific Antibodies. If present at the time of transplantation, may cause renal transplant rejection. The immunological rejection of HLA-identical and a haplo-identical renal transplants suggests that non-HLA antigens such as endothelial antibodies, CMV etc. may also be responsible for the rejection of transplants. Hyperacute rejection could occur due to the presence of HLA antibodies, as patient could become sensitized to these antigens and could show the positive cross match with HLA matched donors and/or a panel of lymphocytes. Under such circumstances, selecting a donor with a negative cross match is often difficult for a highly sensitised patient. Hence, detection of PRA becomes patient to select prospective donor for long term survival of a graft.80 sensitized patients comprising 42 males and 38 females were studied for the presence of PANEL REACTIVE ANTIBODIES (PRA) to select donor for successful transplant and compared the survival of allograft in patients who had anti-HLA antibodies with the patients who did not have such antibodies.
40 sensitized patients were reported who received allograft. The graft survival only amongst the 40 sensitized patients based on years is as follows : Survival is 57.5 in transplants up to 2 years, 20% up to 4 years, 12.5% upto 6 years, and 5% upto 8 years, and 2.5% upto 10 years. The over all graft survival has been 97.5%, while the rejection has been just 2.5%.
4. SEROPOSITIVITY TRENDS IN BLOOD DONORS BOMBAY HOSPITAL BLOOD BANK
Shilpa Joshi, Maya Parihar Malhotra
This is the potrayal of seropositivity in donors of Bombay Hospital donors in last five years 1995-2000 (Jan-March). We tried to find out whether there was any correlation between % of blood groups. It has been stated that donors belonging to blood group ‘O’ are highest (35%) and followup by blood group B (33.5%). Seropositivity is also highest seen in these blood groups. Higher the donors belonging to a particular blood group, higher the chances of seropositivity in that group.Maximum number of donors belonging to age groups 21-30, 31-40, 18-20 that are most sexually active groups therefore higher chances of seropositive donors. Also it was seen that in the last five years, male donors - female donors ratio is 16 : 1, hence higher chances of seropositivity.
As observed during last five years, the percentage of seropositive donors if not decreased, has at least remained constant. Our main aim is to bring it down by ‘safe donation’. In the last five years some of the donor bags that tested positive for a particular test on repeating were negative. But due to the existing guidelines a donor bag that is tested positive for a particular test irrespective of true positive, false positive, discarded. And there was waste of 147 bags in five years i.e. a waste of 6.2% out of total bags - preventable as technical main aim is to bring above numbers down.
 |