Biomedical subjects
V Mithani
Publications and source records attributed to V Mithani.
Wound botulism in injectors of drugs: upsurge in cases in England during 2004.
Wound infections due to Clostridium botulinum were not recognised in the UK and Republic of Ireland before 2000. C. botulinum produces a potent neurotoxin which can cause paralysis and death. In 2000 and 2001, ten cases were clinically recognised, with a further 23 in 2002, 15 in 2003 and 40 cases in 2004. All cases occurred in heroin injectors. Seventy cases occurred in England; the remainder occurred in Scotland (12 cases), Wales (2 cases) and the Republic of Ireland (4 cases). Overall, 40 (45%) of the 88 cases were laboratory confirmed by the detection of botulinum neurotoxin in serum, or by the isolation of C. botulinum from wounds. Of the 40 cases in 2004, 36 occurred in England, and of the 12 that were laboratory confirmed, 10 were due to type A. There was some geographical clustering of the cases during 2004, with most cases occurring in London and in the Yorkshire and Humberside region of northeast England.
An investigation into the microflora of heroin.
In 2000, an unusual increase of morbidity and mortality among illegal injecting drug users in the UK and Ireland was reported and Clostridium novyi was identified as the likely source of the serious infection, although infections due to C. botulinum and Bacillus cereus were also reported. Because heroin was a possibile source of infection, this study investigated the microflora of heroin samples seized in England during 2000 and 2002. Two methods were developed for the examination of the microflora of heroin. The first consisted of suspension of the drug in maximum recovery diluent (MRD) which was inoculated directly into Clostridium Botulinum Isolation Cooked Meat Broth (CBI). The second method rendered the heroin soluble in citric acid, concentrated particulate material (and bacterial cells) by filtration and removed heroin residues by washing with citric acid and phosphate-buffered saline before placing the filter in CBI broth. Duplicate CBI broths from both methods were incubated without heating and after heating at 60 degrees C for 30 min. Subcultures were made after incubation for 7 and 14 days on to eight different solid media. The methods were evaluated with heroin samples spiked with either C. botulinum or C. novyi spore suspensions; recovery of 10 spores in the original sample was demonstrated. Fifty-eight heroin samples were tested by citric acid solubilisation and 34 by the MRD suspension technique. Fifteen different gram-positive species of four genera were recognised. No fungi were isolated. Aerobic endospore-forming bacteria (Bacillus spp. and Paenibacillus macerans) were the predominant microflora isolated and at least one species was isolated from each sample. B. cereus was the most common species and was isolated from 95% of all samples, with B. licheniformis isolated from 40%. Between one and five samples yielded cultures of B. coagulans, B. laterosporus, B. pumilus, B. subtilis and P. macerans. Staphylococcus spp. were isolated from 23 (40%) samples; S. warneri and S. epidermidis were the most common and were cultured from 13 (22%) and 6 (10%) samples respectively. One or two samples yielded cultures of S. aureus, S. capitis and S. haemolyticus. The remainder of the flora detected comprised two samples contaminated with C. perfringens and two samples with either C. sordellii or C. tertium. Multiple bacterial species were isolated from 43 (74%) samples, a single species from the remaining 15. In 13 samples B. cereus alone was isolated, in one B. subtilis alone and in one sample B. pumilus alone. C. botulinum and C. novyi were not isolated from any of the heroin samples. Recommendations for the optimal examination of the microflora of heroin are given.
Healing of spontaneous coronary dissection in the context of glycoprotein IIB/IIIA inhibitor therapy: a case report.
Spontaneous coronary artery dissection is a rare cause of myocardial infarction. It is a condition with greater prevalence in young women, particularly in the peripartum or early postpartum period. It also has been described following intense physical exercise. The pathophysiologic characteristics remain unclear. Unlike atherosclerotic intimal dissection, the dissection plane lies within the media or between the media and adventitia. We describe a case of spontaneous coronary artery dissection in a 44-yr old menstruating woman with mitral valve prolapse, who experienced acute myocardial infarction after twisting and throwing a heavy piece of luggage. Coronary angiography showed coronary artery dissection in a left anterior descending coronary artery at the point of its emergence from its intramural course. An intimal plaque with 90-95% obstruction and reduced (TIMI I) flow was demonstrated. The patient was treated with continued glycoprotein IIb/IIIa inhibitor infusion. Angiographic resolution with return of prompt (TIMI III) flow was noted. Optimal management of spontaneous coronary artery dissection has not been established and may vary, depending upon the presence of intimal versus extramural compromise. Coronary artery bypass, stenting, and thrombolysis have been successful and also have failed, owing to extension of dissection. Our patient is the first reported patient to have received tirofiban therapy in the context of spontaneous coronary artery dissection. Medical therapy has been used most often, and angiographic resolution has been documented at 94 days, 7 mo, and 1 yr. We document the earliest case of spontaneous angiographic resolution-within 20 hr.
Epidemiological typing of Bacillus cereus by amplified fragment length polymorphism.
A simple amplified fragment length polymorphism method was developed for the epidemiological typing of Bacillus cereus. The method was applied to 21 cultures from seven food poisoning and eight non-food poisoning incidents. Results were compared with those obtained by conventional serotyping using flagellar antigens and assessed in relation to epidemiological data. Amplified fragment length polymorphism was found to be highly reproducible and 16 different profiles (each unique to the 15 incidents) were recognized. The method was also able to discriminate three subtypes within serotype H1, which is responsible for the majority of the emetic type of B. cereus food poisoning in England and Wales.
The detection of enterotoxins and toxic shock syndrome toxin genes in Staphylococcus aureus by polymerase chain reaction.
A simple polymerase chain reaction (PCR)-based procedure was developed for the detection of fragments of staphylococcal enterotoxins (SEs) SEA, SEB, SEC, SED, SEE, SEG, SEH, and SEI together with the toxic shock syndrome toxin (TSST-1) genes of Staphylococcus aureus. One hundred and twenty-nine cultures of S. aureus were selected, 39 of which were recovered from 38 suspected staphylococcal food-poisoning incidents. The method was reproducible, and 32 different toxin genotypes were recognized. The presence of SE genes was associated with S. aureus strains reacting with phages in group III, and the TSST-1 gene with phages in group I. There was a 96% agreement between the PCR results for detection of SEA-D and TSST-1 as compared with a commercial reverse passive latex agglutination assay for the detection of SEs from cultures grown in vitro. Enterotoxin gene fragments were detected in S. aureus cultures recovered from 32 of the 38 suspected staphylococcal food poisoning incidents, and of these, 17 were associated with SEE, SEG, SEH, and SEI in the absence of SEA-D. Simple PCR procedures were also developed for the detection of SE directly in spiked food samples, and this was most successfully achieved in mushroom soup and ham. Detection was less successful in three types of cheese and in cream. SEA or SEB were detected by enzyme-linked immunosorbent assay in three food samples (two of which were associated with food poisoning incidents) naturally heavily contaminated with S. aureus: the appropriate SEA or SEB gene fragments were detected directly in these three foods by PCR.
The microbiological quality of cooked rice from restaurants and take-away premises in the United Kingdom.
The microbiological quality of 4,162 samples of cooked rice from restaurants and take-away premises in the United Kingdom was examined, including ready-to-eat rice purchased at point-of-sale and rice that was stored precooked for reheating on demand. The majority of point-of-sale cooked rice samples (1,855 of 1,972; 94%) were of acceptable microbiological quality, but 15 (1%) samples were of unacceptable quality (Bacillus spp. and B. cereus, > or = 10(5) CFU/g; Escherichia coli, > or = 10(4) CFU/g), indicating a potential risk to health. The prevalence of Bacillus spp., B. cereus, and E. coli was significantly greater in precooked stored rice than in point-of-sale cooked rice (P < 0.005 to 0.0005). Bacillus spp. (> or = 10(4) CFU/g), B. cereus (> or = 10(4) CFU/g), and E. coli (> or = 10(2) CFU/g) were present in 7%, 2%, and 9% of precooked stored samples, respectively, compared to 2%, 0.5%, and 1%, respectively in point-of-sale samples. Although final heating at the point of sale reduces the levels of microorganisms present in rice it will not inactivate the B. cereus emetic toxin if present. Rice from Indian premises was of poorer microbiological quality than that from Chinese and other premises. Although most point-of-sale cooked rice samples (94%) were of an acceptable microbiological quality, evidence from this study indicates that the microbiological quality of cooked rice sold from certain outlets in the UK is of concern.