Internal audit in a microbiology laboratory

AIM: To set up a programme of internal laboratory audit in a medical microbiology laboratory. METHODS: A model of laboratory based process audit is described. Laboratory activities were examined in turn by specimen type. Standards were set using laboratory standard operating procedures; practice was observed using a purpose designed questionnaire and the data were analysed by computer; performance was assessed at laboratory audit meetings; and the audit circle was closed by re-auditing topics after an interval. RESULTS: Improvements in performance scores (objective measures) and in staff morale (subjective impression) were observed. CONCLUSIONS: This model of process audit could be applied, with amendments to take local practice into account, in any microbiology laboratory.     

Quality management and the clinical microbiology laboratory

Quality management in today's health care environment requires a fresh approach. Laboratories that have traditionally directed their efforts toward meeting the needs of physicians must now also satisfy the needs of society, the greater public health, and the agency's administrators. Technical advances must today be considered in the context of patient care cost-effectiveness or final outcomes. Examples of strategies for improving quality in the laboratory, such as seeking input from all individuals involved in interpreting or using laboratory test results, forming multidisciplinary committees for development of critical pathways, issuing surveys for assessing the level of satisfaction of the laboratory's customers, and providing visual feedback of the results of activities, are described.     

Role of the microbiology laboratory in the diagnosis of lower respiratory tract infections

A randomized, double-blind trial was undertaken to measure the effects of zinc supplementation on catch-up growth in severe protein-energy malnutrition, with particular reference to linear growth. One hundred forty-one children between the ages of 6 mo and 3 y were enrolled after admission to a nutritional rehabilitation unit in Dhaka, Bangladesh, and randomly assigned to receive elemental zinc by mouth, 1.5 mg/kg for 15 d, 6.0 mg/kg for 15 d, or 6.0 mg/kg for 30 d, and thereafter they were followed for a total of 90 d. Anthropometric outcome measures included change in knee-heel length, midupper arm circumference, subscapular and triceps skinfold thicknesses, and change in height-for-age, weight-for-age, and weight-for-height z scores. Higher zinc doses were not associated with significant change in any anthropometric measurement, but mortality was significantly greater in children who received high-dose zinc (6.0 mg/kg) initially as opposed to those who received low-dose zinc supplementation (1.5 mg/kg) (Yates-corrected chi-square P value of 0.033 and a risk ratio of 4.53; 95% CI: 1.09 < risk ratio < 18.8). We conclude that there is no benefit to using high-dose zinc supplementation regimens and that they could contribute to increased mortality in severely malnourished children.     

Special considerations for the clinical microbiology laboratory in the diagnosis of infections in the cancer patient

The clinical microbiology laboratory faces enormous challenges in diagnosing infections that cause morbidity and mortality in cancer patients. Such laboratories face several issues that surpass those faced by laboratories that perform more routine work. Issues such as sources of clinical specimens, need for correlation and interaction between laboratory and clinical services, blood cultures, susceptibility testing, and the role of new molecular diagnostic techniques are considered in this article.     

Role of the microbiology laboratory in monitoring and identifying resistance: use of molecular biology

Antimicrobial resistance is an increasing problem in the United States. Early detection of emerging trends in antimicrobial resistance may facilitate implementation of effective control measures. Most antimicrobial susceptibility testing is qualitative, in that it categorizes isolates as susceptible, intermediate, or resistant. This approach is relatively inexpensive and generally adequate for clinical purposes. Qualitative susceptibility testing has some limitations for monitoring for emerging resistance. Selective quantitative susceptibility testing may be useful in detecting early trends toward elevated minimal inhibitory concentrations. Molecular methods have a role also in characterizing mechanisms of resistance and in the typing of resistant strains to determine patterns of spread. Laboratory monitoring of emerging resistance must be associated with an effective infection control policy and a willingness to modify practice in a rational manner based upon the trends detected.     

Epidemiological evaluation of mycobacteria isolates in one city hospital: reports from the hospital microbiology laboratory

In Percoll purified Leydig cells from mature rat we have demonstrated that the basal testosterone production (9.5 ng/10(6) Leydig cells/24 h) is increased 10-fold in presence of a saturating amount of hCG (1 IU/mL) and diminished in a dose-related manner when larger concentrations of gonadotropin are used to reach 14 ng/10(6) Leydig cells for 50 IU of hCG. If 40% (v/v) seminiferous tubule medium (STM) is added together with hCG (1 IU/mL) to the incubation medium, a further increase (62%) of testosterone output is noticed. Obviously, when the testosterone production is low as a consequence of a higher dose of hCG (50 IU/mL), the STM (80%) improves the steroid synthesis five-fold (67.4 ng). Concerning the cytoskeletal components (microtubules, intermediate filaments and microfilaments) which have been examined in presence or absence of hCG and STM, we have found a rearrangement of cytoskeletal elements as well as cell-shape changes in relation with hormonal activity of the cells. The most prominent alterations of cytoskeletal elements have been observed after 24 h of incubation with 1 IU/mL of hCG added together with 80% of STM. The obtained results suggest that paracrine factor(s) presents in STM and acting in synergy with LH/hCG generate(s) the rearrangement of cytoskeletal structures which, in turn, facilitates the availability of cholesterol for the mitochondria and finally enhances the testosterone production in the rat Leydig cells.     

How much is the workload of surgeons in Scandinavia?

According to figures presented at the Bianniul General Meeting of the Scandinavian Surgical Society, the mean number of operations performed per surgeon at some clinics of different sizes in Denmark, Finland, Iceland, Norway and Sweden ranged from 90 to 240 in 1996. This corresponds to 2.6 to 8.5 hours actual operating time, though figures are misleading since time spent assisting at operations, or on endoscopies, minor diagnostics and outpatient procedures, and essential pre- and post-operative tasks is not included. This level of operative activity is considered barely sufficient for training surgeons or for maintaining surgical skills. Surgeons could devote more time to surgery if a greater proportion of their non-surgical workload was taken over by other hospital staff, which would also reduce the number of surgeons required.     

Measuring nursing workload: understanding the variability

We reanalyzed parasitaemia profiles of the trypanotolerant N'Dama cattle (Bos taurus), consecutively infected with the same four clones of Trypanosoma congolense. Our analysis shows that each individual parasitaemia is characterized by progressively longer intervals between parasites waves. This pattern is most visible during the chronic phase of infection. In addition, the last of the four infections had a significantly larger overall duration of inter-wave intervals. We retrieved these patterns by numerical simulations of a mathematical model, which incorporates assumptions about the molecular basis of antigenic variation and about the anti-parasitic major immune processes. Six potential factors that may determine parasitaemia pattern were studied: carrying capacity of the host environment, intrinsic growth rate of the parasite, affinity maturation of the immune response, immune cell birth and death rate, levels of antibodies to variant surface glycoprotein and levels of antibodies to invariant antigens. Our simulations suggest that the first five factors are not likely to determine the chronic phase parasitaemia pattern whereas the sixth one, namely, antibody response to invariant antigens, yielded profiles consistent with the experimental data. Being cumulative, the immune response to anti-invariant antigens may be increasingly effective as infection proceeds and in successive infections. Comparisons between N'Dama and Zebu and between chronic and acute phases will be needed to make a statement on the role of this phenomenon in trypanotolerance.     

The use of microbiology in the study of hygiene behaviour

Faecal indicator bacteria have been used to measure levels of hygiene in a variety of settings. This paper describes a study in northern Botswana which used the isolation of faecal indicator bacteria in combination with other quantitative and qualitative techniques to gain information regarding hygiene behaviour. The microbiological samples included, samples from stored drinking water and water sources; eating plates; infant feeding bottles; dishcloths and the fingertips of carers and children. Water was usually clean at source but contaminated after storage. Presumptive faecal coliforms contaminated 31% of the eating plates, 29% of the dishcloths and 40% of the infant feeding bottles. Many of the presumptive faecal coliform isolates were not identified as Escherichia coli, indicating the need for further research into methodologies appropriate for isolating E. coli in tropical climates.     

Detecting short periods of elevated workload: A comparison of nine workload assessment techniques.

The present experiment tested the merits of 9 common workload assessment techniques with relatively short periods of workload in a car-driving task. Twelve participants drove an instrumented car and performed a visually loading task and a mentally loading task for 10, 30, and 60 s. The results show that 10-s periods of visual and mental workload can be measured successfully with subjective ratings and secondary task performance. With respect to longer loading periods (30 and 60 s), steering frequency was found to be sensitive to visual workload, and skin conductance response (SCR) was sensitive to mental workload. The results lead to preliminary guidelines that will help applied researchers to determine which techniques are best suited for assessing visual and mental workload. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Application of mathematical optimization methods in microbiology

Mathematical methods of experiment design have so far found little use in the optimization of microbiological processes. The conventional optimization procedure is still the transformation of functional relationship of n variables into n unidimensional optimizations; furthermore, the Box-Wilson gradient method is often used. This paper presents a review of methods used in other fields, and their application in microbiological practice. The methods are classified according to whether they require, besides the simple determination of the objective function (direct search methods), also the finding of its first (gradient methods) or second derivative (Newton-Raphson method). A modified Rosenbrock's method of direct optimum search and the gradient Box-Wilson method were used in parallel for the optimization of yeast growth on methanol. Their comparison showed that Rosenbrock's method is more suitbale for multiparameter systems.     

Context effects in subjective mental workload ratings

The impact of performance context on subjective mental workload ratings was assessed with the Subjective Workload Assessment Technique (SWAT) and the NASA Task Load Index (TLX). In Experiment 1, a strong context effect was demonstrated. A low range of task difficulty produced considerably higher ratings on a common set of difficulty levels than did a high range of task difficulty. In Experiment 2, increasing the participants' range of experiences during practice eliminated the context effect. We recommend that methods for standardizing context, such as providing experience with the complete difficulty range, be developed for subjective mental workload evaluations. Actual or potential applications of this research include providing methodologies for controlling context effects in practical assessments of mental workload to increase the validity of subjective measures.     

The microbiology of Helicobacter pylori

In this case the authors describe a patient with primary microinvasive adenocarcinoma of the eso-cervix, with the cervical canal not involved by the pathology, diagnosed by colposcopy followed by biopsy. Before the diagnosis of microinvasive adenocarcinoma the patient was scheduled for electrocautery of the suspicious area due to the fact that previous Pap-smears had always been negative. The authors underline the important role of colposcopy as a diagnostic tool that should be mandatory before any surgical therapy on the cervix and that allowed to diagnose such a rare cervical tumor.     

The microbiology of secretory otitis

The AA. realize a comparative study on the differences between the nasopharyngeal microbial flora of 50 children suffering a secretory otitis and other 40 children without middle ear disease. In nasopharyngeal cultures the pathogenic flora (Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Streptococcus beta hemoliticus group A, Staphilococcus aureus) amounted for 96 percent in children with secretory otitis, which figure was reduced to 80 percent in healthy infants (p < 0.05). Haemophilus influenzae was the most identified microorganism in a both nasopharyngeal and otic flora. We have found a significative association (p < 0.001) among nasopharyngeal and otic flora of each individual.     

Cellular microbiology: cycling into the millennium

Cellular microbiology is a newly developing science born from the realization that many different aspects of eukaryotic cell biology are targeted by microbial virulence mechanisms. One example of this is the emerging evidence that several bacteria can interfere, directly or indirectly, with the eukaryotic cell cycle. This article discusses the cell-cycle effects of bacterially generated molecules, their role in virulence and their possible therapeutic potential.     

Assessment and modification of alcoholics drinking behavior in controlled laboratory settings: a cautionary note

A group of 10 prepubertal boys was studied during prolonged exercise (60 min) on bicycle ergometer and on treadmill at two levels of work load (appr. 40% and 60% VO2 max). The hematocrit, serum proteins, Cl- and K+ were followed, and from the blood hematocrit changes the plasma volume changes were calculated. At the exercises of lower intensity of both types a slight hemodilution was found (appr. +5% increase in plasma volume), at higher intensity practically no changes could be demonstrated. These findings are supported by the values of serum protein concentration, where no increase was found, and by the fact that at the lower work loads a rather decreasing trend was found for this blood constituent. These findings are at variance with those in adults under similar conditions. The authors suggest that different changes of plasma volume during exercise in boys than in adults could be related to the disparate lactate production and fate in these age groups.