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At least 271 records · Page 15Linked to original sources

Bronchoalveolar lavage in immunocompromised patients with haematological malignancy--value of new microbiological methods.

PURPOSE: To assess the usefulness of new culture-independent microbiological methods to analyse bronchoalveolar lavage (BAL) fluid from haematological patients with clinical pneumonia. PATIENTS AND METHODS: Results of 135 BALs from 122 disease episodes in 99 patients treated between 1996 and 2002 were retrospectively analysed. Forty-three patients had undergone haematopoietic stem cell transplantation and 56 patients had been treated with conventional chemotherapy for haematological malignancy. In addition to conventional microbiological methods, polymerase chain reaction (PCR) tests for Pneumocystis carinii, cytomegalovirus (CMV), Legionella sp., mycobacterium, Mycoplasma pneumoniae, and Chlamydia pneumoniae and the Aspergillus antigen test were performed. RESULTS: Three (2.2%) quantitative and four (3.0%) special bacterial cultures gave an aetiological diagnosis. A respiratory virus was isolated in 10 episodes (8.2%). The diagnostic yield increased to 35.6% (48 of 135) by other methods. The P. carinii PCR test was positive in 21 of 24 patients with P. carinii pneumonia, being the only microbiological indication of P. carinii in four cases. The CMV PCR test was positive in 18 patients, but in 14 patients the clinical significance of the finding remained unproven. The Aspergillus antigen test was positive in seven of nine patients with aspergillosis, being the only microbiological indication of Aspergillus in three cases. The result of BAL indicated commencement of specific antimicrobial treatment in 27 episodes (22.1%). CONCLUSION: The contribution of new culture-independent methods to the total diagnostic yield was of note. Among these methods, the P. carinii PCR and Aspergillus antigen tests proved the most valuable, while the CMV PCR test was not clinically useful.

Adult↗

Decontamination of laboratory microbiological waste by steam sterilization.

A steam sterilizer (autoclave) was tested to determine the operating parameters that affected sterilization of microbiological waste. Tests involved standardized loads (5, 10 ad 15 lb [ca. 2.27, 4.54, and 6.80 kg, respectively]) contaminated petri plates in autoclave bags placed in polypropylene or stainless steel containers. Thermal and biological data were obtained by using a digital potentiometer and a biological indicator containing spores of Bacillus stearothermophilus, respectively. The transfer of heat was more efficient when smaller loads of microbiological waste were tested and stainless steel rather than polypropylene containers were used. A single bag with the sides rolled down to expose the top layer of petri plates allowed heat to pass better than did a single bag with the top constricted by a twist-tie. The presence of water in the autoclave bag did not significantly improve heat-up time in stainless steel or polypropylene containers. The results of biological tests substantiated the temperature data. When 10 or 15 lb of microbiological waste was exposed to various test conditions, the only condition that ensured the destruction of B. stearothermophilus involved the use of a stainless steel container (with or without water) for 90 min. Autoclaving for 45 min resulted in the destruction of bacteria included in 10 lb (136 +/- 3 plates) or 15 lb (205 +/- 6 plates) of microbiological waste when stainless steel containers with or without water or polypropylene containers with water used, whereas 60 min was required to kill all bacteria if polypropylene containers without water were used.

Hot Temperature↗

Applications of flow cytometry to clinical microbiology.

Classical microbiology techniques are relatively slow in comparison to other analytical techniques, in many cases due to the need to culture the microorganisms. Furthermore, classical approaches are difficult with unculturable microorganisms. More recently, the emergence of molecular biology techniques, particularly those on antibodies and nucleic acid probes combined with amplification techniques, has provided speediness and specificity to microbiological diagnosis. Flow cytometry (FCM) allows single- or multiple-microbe detection in clinical samples in an easy, reliable, and fast way. Microbes can be identified on the basis of their peculiar cytometric parameters or by means of certain fluorochromes that can be used either independently or bound to specific antibodies or oligonucleotides. FCM has permitted the development of quantitative procedures to assess antimicrobial susceptibility and drug cytotoxicity in a rapid, accurate, and highly reproducible way. Furthermore, this technique allows the monitoring of in vitro antimicrobial activity and of antimicrobial treatments ex vivo. The most outstanding contribution of FCM is the possibility of detecting the presence of heterogeneous populations with different responses to antimicrobial treatments. Despite these advantages, the application of FCM in clinical microbiology is not yet widespread, probably due to the lack of access to flow cytometers or the lack of knowledge about the potential of this technique. One of the goals of this review is to attempt to mitigate this latter circumstance. We are convinced that in the near future, the availability of commercial kits should increase the use of this technique in the clinical microbiology laboratory.

Flow Cytometry↗

Microbiology subsystem of a total, dedicated laboratory computer system.

The computer system used by the Microbiology Service of the Clinical Pathology Department, Clinical Center, National Institutes of Health is discussed. This microbiology subsystem is a part of a dedicated on-line laboratory computer system used by the entire department. The laboratory computer is connected on-line to a hospital computer which provides patient admission, transfer, and discharge data. Mark sense worksheets and cathode ray tube terminals are used for result entry and correction. Cumulative patient reports are printed. Results for both active and completed accessions can be easily retrieved on cathode ray terminals in the laboratory. All laboratory data are archived on magnetic tape from which a research data base and microfiched laboratory records are generated. The manner in which the system is integrated in the routine operation of the microbiology laboratory is emphasized. In addition, some of the costs, benefits, liabilities, and pitfalls associated with the introduction of the computer in the laboratory are reviewed. Finally, we have presented our concept of some of the future enhancements to our present system and some of the directions in which any future microbiology system might develop.

Computers↗

Best Practice No 175. Guidelines for virological and non-viral serological examination of specimens in routine diagnostic microbiological laboratories.

Viral examination is routinely carried out in most routine diagnostic microbiology laboratories. Most often, this comprises the detection of viral antigens and antibodies, and less commonly the isolation of viruses and the detection of viral nucleic acids. However, there are no standards or guidelines available for processing these specimens in routine diagnostic laboratories or for referral to specialist virology centres or units. Clinical Pathology Accreditation (CPA) has defined standards for assessing the quality of service provided by laboratories, but these do not include the scientific and technical aspects of provision of service. The Association of Medical Microbiologists has recently published Standards for Laboratory practice in medical microbiology, which covers scientific and technical aspects of provision of microbiology service, mainly bacteriological examination of specimens in routine diagnostic microbiology laboratories. These guidelines are complementary to the CPA guidelines and aim to ensure a consistent and high quality service. This article presents guidelines for the examination of specimens for the diagnosis of viral infections.

Benchmarking↗

Development of a website for clinical microbiology in Brazil.

The quality of Brazilian health services, including clinical microbiology laboratories, varies enormously. We established a Website to provide different professionals with up-to-date information and to create a virtual Brazilian microbiology community. The Website became operational in February 2000 and had 198,976 hits in the subsequent 20 months. There were 1031 user registrations in its virtual community. Different microbiology topics were discussed and three virtual training courses (representing about 300 printed pages of information) were given. The e-learning centre and the Brazilian virtual community created by this Website have facilitated distance learning, and have encouraged professional integration within Brazilian clinical microbiology.

Brazil↗

Prevalence of Listeria monocytogenes in, and microbiological and sensory quality of, rainbow trout, whitefish, and vendace roes from Finnish retail markets.

The prevalence of Listeria monocytogenes in retail roe, as well as the microbiological and sensory qualities of the roe, were studied for three fish species under three different storage conditions. A total of 147 Finnish rainbow trout (Oncorhynchus mykiss), whitefish (Coregonus lavaretus), vendace (Coregonus albula), and burbot (Lota lota) roe samples were bought fresh, frozen, or frozen-thawed from Finnish retail markets. The overall prevalence of L. monocytogenes was 5%; however, the prevalence of the pathogen in fresh roe was 18%. Fresh-bought roe tested positive for Listeria spp. and for L. monocytogenes, respectively, 5 and 20 times as often as did frozen and frozen-thawed roe products combined. The microbiological quality (analyzed as total aerobic heterotrophic bacteria and coliform bacteria) of 78% of the roe samples was unacceptable. Frozen roe samples were found to have the best microbiological quality. According to the results of a sensory evaluation, at least one sensory attribute (appearance, odor freshness, texture, and freshness of taste) was unacceptable for 29% of the roe samples studied. The sensory quality of roe samples bought fresh was better than that of roe samples bought frozen or frozen-thawed. From the results of this study, it is concluded that both the microbiological and the sensory qualities of roe at the retail level need to be improved.

Animals↗

A regional centralized microbiology service in Calgary for the rapid diagnosis of malaria.

CONTEXT: A regional centralized laboratory service for the rapid diagnosis of malaria was implemented 3 years ago in May 1999 within the Division of Microbiology, Calgary Laboratory Services. OBJECTIVE: To describe the design and performance of this unique microbiology laboratory service. DESIGN: Blood specimens must arrive at the central laboratory within 2 hours of collection. Thin blood smears are read and reported from suspected acute cases within 1 hour of receipt, 24 hours per day, 7 days a week, by trained and experienced microbiology technologists. All positive malaria smears are reviewed by a medical microbiologist and confirmed by polymerase chain reaction at a reference laboratory. SETTING: Calgary Laboratory Services provides integrated laboratory services to the Calgary Health Region, an urban area of more than 1 million people. MAIN OUTCOME MEASURES: Performance of the service has been continuously monitored by measuring preanalytic and analytic test turnaround times, test accuracy, clinical relevance, and the results of proficiency testing. RESULTS: More than 90% of blood specimens for malaria from community locations have consistently arrived within 2 hours of collection, and hospitals have reached this target within the past year. Although polymerase chain reaction was more sensitive at detecting the presence of malaria, the expert microscopists were as accurate at determining the type of Plasmodium infection. More than 95% of all positive smear results are consistently reported within 2 hours of receipt of a blood specimen. CONCLUSIONS: Implementation of a regional centralized microbiology service has improved our ability to make a rapid and accurate diagnosis of malaria in this region.

Alberta↗

How is the medical student being trained in microbiology and infections?

Reduction in curriculum time and shifts in interests of microbiology and epidemiology departments have altered the nature of the exposure of medical students to clinical problems of microbiology and infectious diseases. Major objectives of training in microbiology and infectious diseases are poorly met because of the large mass of material the student needs to assimilate. Students graduate from medical school using antimicrobial agents as a substitute for diagnostic acumen, without an understanding of how microbiologic laboratories should be used. Methods to improve this situation should be studied.

Education, Medical↗

Transplantation: the role of microbiologic services.

The role of microbiologic services in transplantation is described. Transplantations have become widely accepted therapeutic practices in which the microbiology laboratory actively participates. Except for problems related to function and rejection of the transplanted organ, infections are the most important concern of the clinician. The infections can be caused by bacteria, fungi, protozoa, and viruses and may occur very early after surgery or as long as six months posttransplant. Specimens (sputum, throat, blood, stool, perirectal, and urine) are routinely sent to the microbiology laboratory before and after transplantation to aid in the diagnosis of potential infections. Rapid diagnostic tests are imperative, and results must be communicated to clinicians expeditiously; this information may be critical in guiding therapy of these infections. The microbiology laboratory plays an essential role in identifying etiologic agents of infections and in determining appropriate therapy.

Bacterial Infections↗

[Waterborne microbiological risk assessment: a state of the art and perspectives].

Microbiological contamination is the most common threat related to drinking water. In developed countries, the current health system provides a good level of protection. However, some facts point out the need to develop further tools for better management of the waterborne risk. Several outbreaks have occurred in the United-States in the past decade. They were most often caused by tap water contamination associated with parasites and viruses, despite good compliance of the water treatment procedures. The chemical risk assessment methodology set up at the end of the 70's can now be applied for microbiological risks. This approach allowed the US authorities to improve their control on waterborne infection risks. Although limited, surveillance data suggest that to date. France has not encountered such outbreaks. However, the baselines and principles of risk management in that area should be also be optimized and updated. This work underlines the limits of the current risk management system. A literature review on microbiological risk assessment is first presented. Applications of this methodology are then commented, advantages and limits of the microbiological risk assessment approach in France are discussed.

Adult↗

Microbiology and food hygiene in mass catering.

Serious consequences can arise from lack of hygiene in mass catering. The uncritical use of routine microbiological tests purporting to measure hygiene merely creates a false sense of security. The microbiological safety of food is achieved by as far as possible ensuring the absence of pathogenic microorganisms and by all means preventing their multiplication. The Hazard Analysis Critical Control Point concept is used to identify microbiologically vulnerable points in the food production process and to determine the most appropriate methods of control to be applied, usually such methods as improved handling techniques, monitoring of temperature and more intensive supervision. Microbiological testing is of value in the initial analysis, at appropriate intervals for verifying the effectiveness of control measures, and in demonstrating to food handlers the reality of the microbial risk if good hygienic standards are not maintained.

Accident Prevention↗

Microbiological examination of ready-to-eat quiche from retail establishments in the United Kingdom.

A microbiological study of ready-to-eat quiche from retail establishments was undertaken to identify risk factors in the production, storage and handling of quiche and to establish their effect on microbiological quality. Examination of cold ready-to-eat quiche from supermarket and other delicatessens, bakers, butchers, cafés, sandwich bars and other retail premises revealed that most (2354 of 2513; 94%) were of acceptable quality; 157 samples (6%) were of unsatisfactory quality and two (< 1%) were unacceptable. Unsatisfactory results were mostly due to high aerobic colony counts. Unacceptable results were due to high levels (> 10(4) cfu/g) of Escherichia coli in two samples. Salmonella spp. were not detected in any of the samples. Satisfactory microbiological quality of ready-to-eat quiche was associated with premises that had management food hygiene training and hazard analysis in place. The microbiological quality of this food was also associated with premises type, quiche type, slicing and serving methods, and existing Local Authority Inspectors' Consumer at Risk scores.

Communicable Disease Control↗

Microbiological examination of ready-to-eat burgers sampled anonymously at the point of sale in the United Kingdom.

During May and June 1999 a microbiological study of ready-to-eat burgers purchased anonymously from burger outlets (combined take-away and burger restaurants, take-away-only fixed premises, mobile vendors, temporary stalls and other burger outlets) was undertaken. The intention was to determine the microbiological quality of ready-to-eat burgers as purchased by customers of take-away premises and to ascertain, where information was available, whether the Chief Medical Officer's advice on cooking burgers was being followed. Examination of 3,128 ready-to-eat burgers found that 2,868 (92%) were of acceptable quality and 260 (8%) were of unsatisfactory quality. Unsatisfactory results were mostly due to high aerobic colony counts (ACCs). Salmonella spp., Campylobacter spp. and Escherichia coli O157 were not detected in any of the samples examined. Acceptable microbiological quality of ready-to-eat burgers was associated with outlets, such as combined take-away and burger restaurants and in particular national franchise outlets, which had management food hygiene training and hazard analysis in place. Poor microbiological quality was associated with undercooking and local outlets as indicated by Local Authority Inspectors' Consumers at Risk scores.

Bacteria↗

Microbiological quality of hemodialysis water in a three-year multicenter study in Uruguay.

BACKGROUND: The microbiological quality of treated water is a very important issue in hemodialysis (HD) centers. Water treatment may have a dramatic effect on microbial contamination because of bacterial colonisation of the different parts of the system such as storage tanks, softeners or deionisers. Therefore, HD centers must have stringent quality programmes including regular water monitoring for microbiological analysis. We report the results of a three-year study (July 97 to June 2000) including bacteriological quality analysis of 3129 water samples from 32 out of 38 HD centers throughout Uruguay. METHODS: Bacteriological analysis of water samples was based on heterotrophic count, total coliform count and Pseudomonas aeruginosa presence/absence, according to the procedures proposed by the Association for the Advancement of Medical Instrumentation (AAMI). RESULTS: Heterotrophic counts of 83% of the samples were under 200 colony forming units (CFU) /mL (AAMI limit of compliance) and the water samples after the final bactericidal treatment showed 99% compliance. The points showing the worst results were softeners and deionisers (60% acceptance). CONCLUSIONS: In comparison with a similar study in Uruguay, from January 96 to June 97 at the same microbiological laboratory, there has been a marked improvement in the microbiological quality of water for hemodialysis.

Bacterial Infections↗

[A microbiological and physicochemical analysis of the water in swimming pools on the island of Tenerife].

BACKGROUND: A microbiological and physiochemical analysis has been made from 60 samples of water from two swimming pools in Santa Cruz de Tenerife in order to know the hygienic condition and to establish the most adequate microbiological indicators. The water of the two swimming pools has a different origin: sea water (Swimming pool B) and public supply (Swimming pool A), and so, different processings are used. METHODS: The analytical methodology was based on the Spanish current day regulations for the control of drinkable waters for public use, as well as on the methods the American Public Health Association recommends. RESULTS: There have been found differences between one swimming pool and the other, depending basically on the water characteristics and the processings used to treat it; there exists a greater microbiological contamination in the samples from the swimming pool B. It has been proved that medium R2A is better than medium P.C.A. to recount total mesophilic aerobes in both swimming pools. CONCLUSIONS: The isolation of St. aureus species in samples from the swimming pool B makes of it a possible microbiological indicator for the hygienic control of swimming pool waters of marine origin. Likewise, the presence of mycobacterium species in samples of the swimming pool A confirms its resistance to concentrations of growth inhibitors of free chlorine.

Chemical Phenomena↗

[Sampling plans and microbiological criteria as risk management options in recently developed food safety concerns].

In connection with the World Trade Organization SPS-Agreement new concepts for ensuring food safety have been discussed for some years now. Main topics have been quantitative risk analyses investigating relationships between microbial concentrations in foods and disease probabilities as well as the concept of food safety objectives developed by ICMSF. So far food safety demands have been defined as microbiological criteria. However, usually it is not transparent, whether sampling plans incorporated in such criteria are based on specific prescriptions with regard to decision reliability and tolerable food qualities. In addition, it is still to be discussed, which parts microbiological criteria can play in connection with new concepts of food risk management, for instance as an option to test whether food safety objectives are met or not. The performance of microbiological sampling plans, as visualized by operation characteristic curves, assumptions made in this context, and relationships between food safety objectives and microbiological criteria as well as implications for food safety issues are investigated in this paper.

Colony Count, Microbial↗

A model for consolidation of clinical microbiology laboratory services within a multihospital health-care system.

To determine the cost-effectiveness of consolidating clinical microbiology services in a three-hospital health-care network while maintaining high-quality laboratory services, a retrospective review of the total costs of maintaining separate clinical microbiology laboratories within our health-care system was compared to the cost of providing these services after consolidation. Turnaround times before and after consolidation were compared to assess efficiency of the consolidated services. Input of clinicians was also solicited to ensure that quality of services and customer satisfaction remained high. The results of the consolidation project show that the net fiscal saving because of consolidation of clinical microbiology services within our health-care system will be approximately 100,000 dollars per fiscal year. This value includes increased courier charges as well as personnel savings. Although fiscal savings are an integral part of any laboratory consolidation plan, the financial considerations must be balanced by quality of service. The response to consolidation from clinicians was decidedly mixed before implementation of the plan because of fear of increased turnaround times and limited access to laboratory information. The consolidation process, however, was smooth with few physician complaints. The consolidation of our clinical microbiology services illustrates that significant financial savings can be achieved without compromise of efficiency or quality of service.

Alabama↗