Biomedical subjects

C Mukerjee

Publications and source records attributed to C Mukerjee.

9 recordsLinked to original sources

PubMed2002

Determination of the optimum incubation period of continuously monitored blood cultures from patients with suspected endocarditis or fungaemia.

AIM: It is routine practice to prolong the incubation period of blood cultures from patients with suspected subacute bacterial endocarditis (SBE) or fungal infection. The protocol in this laboratory required 28 days incubation with weekly subcultures. Following the introduction of automated continuously monitored blood culture instruments, the duration of incubation for specimens from these categories of patients was reviewed. METHOD: In a retrospective study of blood culture specimens submitted from 1 July 1994 to 31 July 1998, the time from collection to a positive signal from the BacT/Alert automated blood culture system, in patients suspected of SBE or fungal infection, was assessed. RESULTS: From 355 patient episodes, 896 bottles were incubated for up to 28 days, during which time 116 bottles (40 patient episodes) signalled positive. Significant organisms from suspected endocarditis patients were isolated from 87 bottles (87%), with the time to detection ranging from 9 to 96 hours. The data collected from significant isolates obtained from clinically suspected fungaemias were extremely small, prompting a review of the total fungal isolates from all blood culture bottles incubated during the study period. Yeast isolates were obtained from 78 (0.08%) bottles with the detection time ranging from 15 to 144 hours. CONCLUSION: The practice in this laboratory now is to incubate blood cultures for up to 7 days when the clinical notes indicate the possibility of SBE or a fungal infection.

Bacteria↗

PubMed2000

The relative incidence of detrusor instability and bacterial cystitis detected on the urodynamic-test day.

OBJECTIVE: To determine whether patients with detrusor instability (DI) were more likely to have bacterial cystitis or significant bacteriuria on the urodynamic-test day than were women with a stable bladder. PATIENTS AND METHODS: A catheter specimen of urine was cultured (overnight in air) from 862 consecutive women at the time of urodynamic testing. The upper urinary tract was imaged, with cystoscopy when indicated, to exclude upper tract lesions or malignancy. The percentage of patients with pure idiopathic DI and those with mixed DI/genuine stress incontinence (GSI), in whom the urine culture was positive, was compared with the percentage who had a stable bladder (pure GSI or urodynamically normal) and a positive urine culture, both for the entire dataset and for women aged > or <65 years. Data were also analysed to detect the converse relationship; in those women found to have bacterial cystitis, the relative risk of being found urodynamically unstable or stable was determined. RESULTS: The likelihood of bacterial cystitis occurring in patients with idiopathic DI (5.6%) was significantly greater than that in patients with GSI (1.1%; P = 0.009, Fisher's exact test). The proportion of patients with DI and significant bacteriuria (15. 4%) was significantly greater than that in patients with GSI (7.9%; P = 0.02). In patients with combined pure and mixed DI, bacterial cystitis was significantly more likely to occur (6.3%) than in GSI (P < 0.001), but bacteriuria was no more likely (12.5%, P = 0.09). Conversely, of those women found to have bacterial cystitis, the relative risk of having an unstable bladder was increased (+1.56), but for those with bacteriuria the relative risk of detrusor instability was not increased. CONCLUSION: There was a significant association between idiopathic DI and bacterial cystitis, and we suggest that in some women with an unstable bladder, urinary infection may enhance detrusor contractility. Nevertheless, large-scale studies are needed of the temporal relationship between the onset of bacterial cystitis and the onset of DI.

Adult↗

PubMed2000

Group B streptococcus screening in pregnant women: a comparison of three media.

This study compared the relative isolation rate of Group B Streptococcus (GBS) from 663 low vaginal swabs, collected from antenatal patients, on three media: horse blood agar plus neomycin (75 mg/l) (Neo), Islam agar (Islam) and Islam agar plus nalidixic acid (15 mg/l) and colistin sulphate (10 mg/l) (Islam Plus). One hundred and forty-seven (22%) GBS were isolated. At 24 hours the isolation rate was highest using Neo, but within 72 hours there was little difference. The isolation rates for Neo, Islam and Islam Plus at 24 hours were 124 (18.7%), 103 (15.6%), 109 (16.4%) (P < 0.05); at 48 hours 125 (18.9%), 116 (17.5%), 121 (18.1%) (P > 0.1); and at 72 hours 125 (18.9%), 121 (18.3%) and 127 (19.1%) (P > 0.1), respectively. Twenty-two isolates were missed on Neo, 26 on Islam and 20 on Islam Plus. Of those missed on Islam agars, 12 failed to produce pigment and were only detected on Neo. The disadvantage of Neo is the need to perform additional tests to confirm the identity as GBS. In the present study 100 suspicious colonies were identified as Group D.

Adult↗

PubMed1998

Effect on organism recovery rate from BacT/Alert blood cultures with reduced incubation period.

This retrospective study evaluated 15,377 sets of BacT/Alert blood cultures to determine incubation time for blood cultures. Ninety-six per cent (1476) of total isolates signalled positive within five days and 56 isolates turned positive in five to seven days. Of the 56 organisms recovered between five and seven days, 49 were considered contaminants and seven were considered clinically significant. On assessing the medical records of the patients with the seven clinically significant isolates, it was determined that the clinical outcome would not have changed if these isolates were missed. We conclude that a five day incubation protocol reduces the recovery of skin contaminants while not significantly decreasing the recovery of clinically significant organisms. The data suggest that the incubation time can be further reduced but this policy will depend on the individual institution and their patient population mix.

Bacteria, Aerobic↗

PubMed1998

Efficacy of a mouthrinse containing 0.05% cetylpyridinium chloride for the control of plaque and gingivitis: a 6-month clinical study in adults.

The objective of this 6-month, double-blind, clinical study, conducted following the American Dental Association (ADA) guidelines, was to provide an assessment of the effectiveness of a newly developed mouthrinse containing 0.05% cetylpyridinium chloride (CPC) for the control of supragingival dental plaque and gingivitis. Adult men and women from the Manchester, England, area were entered in the study, and stratified into two treatment groups (CPC mouthrinse and control mouthrinse), which were balanced for baseline Quigley-Hein Plaque Index scores and baseline Löe-Silness Gingival Index scores. Participants were given an oral prophylaxis and instructed to brush their teeth twice daily (morning and evening) for 1 minute with a soft-bristled toothbrush and fluoride dentifrice provided, immediately followed by rinsing for 30 seconds with 15 cc of their assigned mouthrinse. Examinations for supragingival plaque and gingivitis were conducted after 3 months' and again after 6 months' participation in the study. One hundred eleven participants complied with the protocol and completed the entire 6-month clinical study. At both the 3- and 6-month study examinations, the CPC mouthrinse group exhibited statistically significantly less supragingival plaque and gingivitis than did the control mouthrinse group. At the 6-month examination, the magnitude of these differences met or exceeded 24% for all 4 parameters measured (28.2% for Quigley-Hein Plaque Index, 63.4% for Plaque Severity Index, 24.0% for Löe-Silness Gingival Index, and 66.9% for Gingivitis Severity Index). The magnitude of the reductions in supragingival plaque and gingivitis were adequately large to support a claim of efficacy, in accordance with the criteria provided by the published guidelines of the ADA for the demonstration of the efficacy of a chemotherapeutic agent for the control of supragingival plaque and gingivitis. Thus, the results of this 6-month clinical study support the conclusion that a newly developed mouthrinse containing 0.05% cetylpyridinium chloride provides a statistically significant, clinically relevant level of efficacy for the control of supragingival plaque, and for the control of gingivitis, in accordance with the criteria provided by current ADA guidelines.

Adolescent↗

PubMed1995

A comparative study of the BBL crystal enteric/nonfermenter identification system and the biomerieux API20E and API20NE identification systems after overnight incubation.

The BBL Crystal Enteric/Nonfermenter (Crystal, Becton Dickinson Microbiology Systems) is a new multi-test identification system for Gram negative rods requiring no oil overlay or addition of reagents. One hundred and three selected Gram negative rod isolates from routine clinical specimens were tested in parallel using the appropriate API20E or API20NE (BioMerieux) reading after overnight incubation. The isolates included in the study, and the number tested, were as follows: Acinetobacter sp, 8; Aeromonas hydrophila, 1; Citrobacter diversus, 1; Citrobacter freundii, 1; Escherichia coli, 13; Enterobacter aerogenes, 10; Enterobacter agglomerans, 2; Enterobacter cloacae, 6; Klebsiella oxytoca, 6; Klebsiella pneumoniae, 12; Morganella morganii, 2; Proteus mirabilis, 6; Pseudomonas aeruginosa, 21; Salmonella sp, 2; Salmonella typhi, 1; Serratia marcescens, 1; Shigella sonnei, 2; Shigella sp, 2; Vibrio metschnikovii, 1; Xanthomonas maltophilia, 3; and, Yersinia enterocolitica, 2. The API20E and API20NE systems combined identified 74.8% (77/103) and the Crystal 97.1% (100/103) of isolates. Twenty six isolates required repeat and/or additional tests for correct identification with the API systems compared to 3 with the Crystal. Crystal is more convenient than API for routine clinical use because it requires fewer repeat and/or extra tests, and is easier and less time consuming to use.

Bacterial Typing Techniques↗

PubMed1994

Evaluation of direct disc diffusion susceptibility testing for bacteriuria using diluted urine against standard CDS method.

Consecutive urine specimens with > or = 10(9) organisms/L on microscopy were diluted 1:100 and direct disc diffusion susceptibility tests performed. Subsequently, the standard Calibrated Dichotomous Sensitivity (CDS) test was performed on all isolates. Urines with > 2 Isolates or where growth was < 10(8) colony forming units (CFU)/L were excluded. Only Gram negative organisms were considered. 361 urines were evaluated, 324 with one and 37 with 2 isolates, comprising 255 Escherichia coli, 49 klebsiella, 41 proteus, 29 either citrobacter, enterobacter, providencia, serratia or alcaligenes, and 14 Pseudomonas aeruginosa. There were 2272 organism/antimicrobial test comparisons. A concordance of 98.5% was obtained. The results are considered acceptable for routine clinical use.

Anti-Bacterial Agents↗

PubMed1992

Assessment of the effects of dentifrices on plaque acidogenesis via intra-oral measurement of plaque acids.

Dionex ion chromatography was used for identification and quantification of the plaque acids (formate, lactate, acetate, and propionate) formed in vivo following a sucrose rinse. Consistent with other literature reports, lactate and acetate were the predominant acid species generated by plaque. This micro-analytical technique was used for investigation of the effects of dentifrice formulations containing NaF, xylitol, or NaF/xylitol on plaque acid metabolism. Neither a single nor multiple exposures (three times daily for one week) to the experimental dentifrices significantly altered the profiles of the individual acids or total plaque acidity relative to the placebo dentifrice. The lack of an effect of fluoride and xylitol on plaque acid metabolism is attributed to the variability of dental plaque and the low concentrations of active ingredients reaching the plaque. However, we believe that, with further improvement in sampling technique and study design, this approach may prove useful for the study of the effects of active ingredients (i.e., anticaries agents) on plaque acidogenesis.

Acetates↗

PubMed1989

In vitro and in vivo studies on triclosan/PVM/MA copolymer/NaF combination as an anti-plaque agent.

A combination of triclosan, copolymer of PVM/MA and NaF has been optimized in vitro and in vivo for plaque effect. Triclosan (2, 4, 4' trichloro-2'-hydroxydiphenyl ether), a non-cationic antibacterial, was compatible with anionic surfactant, NaF and PVM/MA copolymer as evaluated by in vitro antibacterial tests. The in vitro uptake of triclosan on the saliva-coated hydroxyapatite disks, extracted human teeth and oral buccal epithelial cells was enhanced two fold in the presence of PVM/MA copolymer when compared to the uptake in the absence of the copolymer. The combination consisting of 0.3% triclosan/2% PVM/MA copolymer/1100 ppm NaF was found to be highly effective on reducing smooth and fissure caries, and plaque extent compared to to 1100 ppm/NaF by itself in rats when applied topically. The combination also showed significantly more fluoride uptake and reduction in enamel solubility than 1100 ppm/NaF. The results of these studies indicated that this optimized combination was an effective antiplaque/anticaries agent in vitro and in vivo.

Animals↗