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At least 19 recordsLinked to original sources
PubMed2026

Microbiological analysis and whole-genome sequencing of Neisseria gonorrhoeae from the microbiological failures in the international, zoliflodacin, phase 3, clinical trial for treatment of uncomplicated urogenital gonorrhoea: a retrospective, genomic, observational study.

BACKGROUND: Zoliflodacin, a first-in-class oral bacterial, DNA gyrase (GyrB) inhibitor, showed non-inferiority to ceftriaxone combined with azithromycin in a recent large international, phase 3, randomised controlled trial for treatment of uncomplicated urogenital gonorrhoea. The aim of this study was to describe the microbiological and whole-genome sequencing (WGS) analyses of paired baseline (pre-treatment) and test-of-cure (TOC) gonococcal isolates from the zoliflodacin phase 3, randomised controlled trial to further characterise and evaluate the protocol-specified microbiological failures with zoliflodacin (n=22) or ceftriaxone and azithromycin (n=1). METHODS: In this retrospective, genomic, observational study, results from antimicrobial susceptibility testing (agar dilution method) of isolates (n=960; 936 baseline isolates from 763 participants and 24 TOC isolates [23 with a paired baseline isolate in the same anatomical site] from 20 participants) collected during the zoliflodacin phase 3, randomised controlled trial done in 16 outpatient clinics in Belgium, the Netherlands, South Africa, Thailand, and the USA (Nov 6, 2019-March 16, 2023) are described. WGS analysis was performed on paired baseline and TOC isolates from participants with microbiological failures (zoliflodacin 44 isolates [19 participants]; ceftriaxone and azithromycin two isolates [one participant]), and the three baseline isolates with highest zoliflodacin minimum inhibitory concentration (MIC 0·5 mg/L). FINDINGS: All isolates were inhibited by the same zoliflodacin concentrations (MICs ≤0·008 to 0·5 mg/L) as wild-type strains cultured internationally in 2013-23. In participants with a microbiological failure after zoliflodacin treatment (n=22, 19 participants), zoliflodacin MIC values for baseline and TOC isolates were similar, and resistance selection was lacking. WGS showed that five (23%) of 22 infections (95% CI 10-43 [in four participants]) of zoliflodacin microbiological failures had different strains at TOC versus baseline. In 17 zoliflodacin microbiological failures (15 participants), isolates at baseline and TOC were indistinguishable. 13 of these 17 microbiological failures, corresponding to 59% (95% CI 39-77; 13 of 22) of all zoliflodacin microbiological failures, were in urogenital or rectal sites in 11 participants and the isolates had zoliflodacin MICs less than or equal to 0·008 to 0·25 mg/L. The single microbiological failure after ceftriaxone and azithromycin treatment had different strains at TOC versus at baseline. No sequenced isolates had mutations associated with elevated zoliflodacin MICs. INTERPRETATION: In the zoliflodacin phase 3, randomised controlled trial, 23% of the zoliflodacin microbiological failures and the single ceftriaxone and azithromycin microbiological failure had different gonococcal strains at TOC versus baseline, which suggests reinfections and not treatment failures. In addition, 59% of the zoliflodacin microbiological failures, all in anogenital sites, had no obvious microbiological explanation based on the low zoliflodacin MICs, previous pharmacodynamic studies, and no evidence of resistance selection after zoliflodacin therapy. A reinfection as the cause for these microbiological failures could not be excluded. We recommend that WGS is implemented in future randomised controlled trials for gonorrhoea treatment to further evaluate possible microbiological failures, exclude reinfections (to avoid underestimating the cure rates), and characterise antimicrobial resistance determinants. FUNDING: GARDP through grants from Germany BMFTR (03KA1831), UK DHSC as part of GAMRIF, Japan MHLW, the Netherlands' Ministry of Health, Welfare and Sport and Directorate-General for International Cooperation, the Federal Office of Public Health of Switzerland, the Canton of Geneva, Switzerland, and Örebro University Hospital, Sweden.

Humans↗
PubMed2003

Results of the survey of the quality assurance for commercially prepared microbiology media. Update from the College of American Pathologists Microbiology Surveys Program (2001).

CONTEXT: Beginning in 1985, state-of-the-art surveys by the College of American Pathologists (CAP) led to M22-A guidelines by the National Committee for Clinical Laboratory Standards (NCCLS) for quality assurance (QA) of various commercially prepared isolation and diagnostic microbiology media. Some medium types were declared exempt from routine QA testing by each laboratory user, but manufacturer QA was maintained and specified in great detail. No update has occurred in more than 15 years as more complex media have been introduced into clinical microbiology practice. OBJECTIVE: To reassess the quality of commercially prepared microbiology media in the United States for the revision of NCCLS document M22-A2. Methods.-A questionnaire was designed to conform to that used by the CAP in 1985 and 1988, and was updated by lists of 52 recently introduced diagnostic media. Queries included details of laboratory QA in the last 12 months, such as number of lots tested, number of items in a lot, number of items in a quality control (QC) sample, number of lots failed, and reasons for lot failure. All CAP Microbiology Surveys participants received the document in late 2001. RESULTS: Data from nearly 300 000 media lots representing 32.7 million medium items were received from more than 3000 CAP Surveys subscribers. Lot raw data failure rates for all media ranged from 0.10% to 9.87% (average, 1.01%). Failures with media having a significant QC experience (> or =1000 lots or > or =100 000 items) adjusted for QC strain-based failures (so-called extrapolated failure rate) ranged from 0.04% to 1.34% (average, 0.40%). The threshold rate for QA exemption from 1985 analyses was expanded to 0.50% or less and now allows exemption of 27 media evaluated in this study. Local laboratory QA must remain in force (M22-A2) for the other 25 products. CONCLUSIONS: Generated QA failure results from the CAP Microbiology Surveys supplement recent results of the NCCLS M22 Subcommittee that will lead to more practical media QA guidelines and could significantly decrease costs for clinical microbiology laboratories through focusing QC on a smaller number of the most at-risk diagnostic products.

Bacteria↗
PubMed1980

[Problems of maintaining hygienic and microbiological quality standards in the production of foodstuffs, particularly those of vegetable origin. Second report: Demands regarding hygiene and microbiology-theory is useless without practice (author's transl)].

Many legal regulations exist on the hygienic-microbiological properties of food products. The 'Länder-Speiseeisverordnungen' (County Ice Cream Regulations), the 'Diät-Verordnung' (Dietary Regulation) and the 'Trinkwasser-Verordnung' (Regulation on Potable Water) are examples for the frequent inadequacies inherent in these regulations. Caution is indicated against any new proposals for the establishment of additional hygienic-microbiological regulations without sufficient practice-related reasoning unless a revision and improvement of inadequate, already existing regulations has been carried out. Practicable procedures have to be prepared not only to maintain the hygiene in Catering facilities, but also for the evaluation of food products and raw materials according to hygienic-microbiological criteria: Although commonly assumed, the 'Microbe Counts' alone are not sufficient for the determination of the hygienic conditions. Therefore, inspite of all the weak points inherent in quality control procedures - e. g. possible sick, co-workers, only random sample control of raw material supplies - such adapted systems (good manufacturing practice) have to be enforced with special emphasis on the economy of the control expenditure, interdisciplinary aspects, governmental control and consumer information. Examples from literature and own experience demonstrate that the importance of the 'Fecal Indicators' for the judgement of 'hygienic conditions' in food production are rather limited and a correct evaluation only by 'Bacterial Plate Counts' is not possible due to the variation of germ density within one sample. Microbiological investigations of food products according to statistic rules require such an expenditure that they cannot generally be used as routine control procedures. A possible documentation is shown which allows - even without statistic investigations, at least retrospectively - the preparation of a survey on the microbiological properties of raw materials generally available on the market and which makes it possible to recognize and reject any unqualified microbiological limiting value requirements.

Bacteria↗
PubMed2002

[Medical supports for the diagnosis of infectious diseases; the role and responsibilities of clinical pathologist and microbiology technologist. Acute purulent meningitis; the position of the technologists in microbiology laboratory].

The features and limitations of microbiology processes for the diagnosis of bacterial meningitis were summarized. Requests for physicians were also emphasized. The microbiology laboratory should be responsible for providing highly reliable and concordant data with a variety of clinical settings. Technologists in a microbiology laboratory should perform following subjects: i) Direct smear examination: Presumptive identification by the observers with abundant experience and sufficient training. ii) Rapid bacterial antigen detection tests: Active utilize alone in combination with the direct microscopy. iii) Culture: Cost effective utilize for appropriate media and culture condition based on the bacteriological statistics. Report with bacteriological interpretations and with additional proper comments, if necessary. iv) Antimicrobial susceptibility tests: Determination of penicillin resistance among the strains of penicillin-resistant or-intermediate Streptococcus pneumoniae (PI or PRSP) should be confirmed by MIC procedures; Detection of beta-lactamase producing Haemophilus influenzae (BLP) could detect by beta-lactamase tests, but not clearly identify for beta-lactamase-negative ampicillin-resistant isolates (BLNAR). In addition, a laboratory should provide appropriate information by using the accumulated routine clinical microbiology data, which may help to physicians in selecting an empiric therapy and to the microbiology technologists in processing the routine microbiology. In recent status, the most common organisms isolated from patients with bacterial meningitis continue to be S. pneumoniae and H. influenzae. Among S. pneumoniae strains, penicillin-intermediate(PISP) and--resistant(PRSP) strains had exceeded 50%, and the strains of beta-lactamase producing H. influenzae (BLP) had decreased with less than 10% and beta-lactamase negative ampicillin-resistant strains (BLNAR) have increasing. To providing rapid and accurate results, a laboratory should require the clinical information, including patient's age, major presenting symptoms, and receive antimicrobials prior to specimen collection.

Acute Disease↗
PubMed1992

[Clinical microbiological service in general practice in the municipality of Copenhagen. Experiences from the clinical microbiological department at the Hvidovre Hospital 1987-1991].

Since 1987, the clinical microbiological department in Hvidovre Hospital has served physicians in primary health care in the municipality of Copenhagen with microbiological diagnoses and instruction. This paper describes the service model and experience gained during the past four years. During the observation period, the annual number of analyses doubled. In 1990, 66,460 analyses were performed for a total of 399 physicians. The number of specimens per physician varied from 1 to 1903 with a median value of 95. Chlamydia specimens (CS) and vaginal discharge specimens (VDS) examined for yeasts, Gardnerella and Trichomonas comprised the two largest categories. In spite of the increasing number of specimens, the overall rate of positive samples remained unchanged. Physicians who sent many CS in 1990 scored a significantly lower positive rate than physicians who sent few, however, no corresponding difference was demonstrable for VDS. Thus, there is scarcely evidence to assume that microbiological specimens are taken on less strict indications than previously. The increasing number of specimens reflects rather a hitherto uncovered need for microbiological diagnosis in primary health care. Specialists scored significantly lower positive rates for CS and VDS than general practitioners, which may indicate that these specimens are often repeated unnecessarily, when a patient is referred to a specialist. With a view to decentralizing selected categories of specimens, including VDS, courses in microscopy were held, in which one fourth of the physicians of the region participated. A questionnaire survey evaluating the course showed that there is a great interest among physicians in primary health care to perform simplified microbiological diagnosis, but there is still a great need for training and education.

Denmark↗
PubMed1999

Microbiological safety evaluations and recommendations on sprouted seeds. National Advisory Committee on Microbiological Criteria for Foods.

In 1997, the National Advisory Committee on Microbiological Criteria for Foods (NACMCF/the Committee) was asked to review the current literature on sprout-associated outbreaks: identify the organisms and production practices of greatest public health concern: prioritize research needs: and provide recommendations on intervention and prevention strategies. In response to this charge, the Fresh Produce Work Group (FPWG) documented the relevant epidemiology and microbial ecology of sprout-associated outbreaks and reviewed current industry practices and initiatives related to the growing of seed and the production of sprouts. Sprouts have been identified as a special problem because of the potential for pathogen growth during the sprouting process. If pathogens are present on or in the seed, sprouting conditions may favor their proliferation. There is no inherent step in the production of raw sprouts to reduce or eliminate pathogens. Contaminated seed is the likely source for most reported sprout-associated outbreaks. Research has been initiated on methods to reduce or eliminate pathogenic bacteria on seeds and sprouts and some treatments show promise. However, to date, no single treatment has been shown to completely eliminate pathogens under experimental conditions used. Finally, the Committee found that, at the time of the charge, there was a lack of fundamental food safety knowledge along the continuum from seed production through sprout consumption. More recently, many have become aware of the potential for this food to be a vehicle for foodborne illness and the need for appropriate controls: however, such awareness is not universal. Although seed appears to be the most likely source of contamination in sprout associated outbreaks, practices and conditions at the sprouting facility may also impact on the safety of the finished product. In recent sprout-associated outbreak investigations, facilities associated with outbreaks did not consistently apply seed disinfection treatments prior to sprouting. Conversely, facilities that used seed from the same lot as an implicated facility, but had not been associated with reported illnesses, appear to have been consistently using seed disinfection treatments, such as 20,000 ppm calcium hypochlorite, to disinfect seed prior to sprouting. The Committee has developed a number of specific recommendations, including: 1. The knowledge of all interested parties pertaining to the microbiological safety of sprouted seeds must be enhanced; government and industry should develop education programs for seed and sprout producers on basic principles for microbiological food safety, good agricultural practices, good manufacturing practices, and hazard analysis and critical control point (HACCP) systems. 2. Good agricultural practices should be systematically implemented to reduce the potential for microbial contamination of seeds for sprout production. 3. Seed cleaning, storage, and handling practices that minimize the potential for microbial contamination should be developed and implemented. 4. Seeds should be treated with one or more treatments that have been shown to reduce pathogenic bacteria that may be present. Intervention strategies that deliver less than a given reduction (at this time, 5-log) in levels of Salmonella spp. and enterohemorrhagic Escherichia coli O157 should be coupled with a microbiological testing program. 5. Establish good manufacturing practices and food safety systems, including regulatory oversight, microbial testing, adoption of HACCP, and improved traceback, that systematically look for means to prevent seeds from serving as the vehicle for foodborne disease, and 6. Conduct research related to the microbiological safety of sprouted seeds, particularly in the areas of pathogen reduction or elimination, sources of contamination and its prevention, and preventing or retarding pathogen growth during sprouting.

Disease Outbreaks↗
PubMed1995

Microbiological criteria for retail foods. Professional Food Microbiology Group (PFMG) of the Institute of Food Science and Technology (IFST).

This article proposes that microbiological criteria should only be drawn up and applied to foods if there is a full understanding and consideration of raw material selection, production process, packaging and finished product characteristics. The combined knowledge and expertise of public sector microbiologists and food industry microbiologists and technologists need to be harnessed in the establishment of such criteria. In this manner, microbiological criteria could be derived to the overall benefit of the consumer. A meeting of the Society for Applied Bacteriology held in November 1994 considered the issue of microbiological standards for foods and, in this paper, the recently formed PFMG presents an opinion on the 'Provisional microbiological guidelines' published by the Food Surveillance Group of the Public Health Laboratory Service.

Food Microbiology↗
PubMed1994

"Teaching microbiology" vs. "learning microbiology".

Microbiology is great! Our challenge is to convey that excitement to our students and to stimulate them to actively pursue knowledge about microbiology. Their future will be loaded with microbial issues, ranging from safety of the hamburgers they eat to the appropriateness of the therapies for their diseases. Thus it is critical that all of our students develop problem-solving skills in microbiology. In this article, I discuss ideas about current challenges, as well as opportunities, related to teaching and learning about microbiology.

Humans↗
PubMed1997

Establishment of microbiological safety criteria for foods in international trade. International Commission on Microbiological Specifications for Foods.

Microbiological safety is achieved by applying good hygienic practices throughout the food chain, "from farm to fork". Governmental food control is traditionally based on inspection of the facilities where foods are handled, and on testing food samples. Testing is usually applied to imported foods, when no information concerning the safety of a consignment is available. The microbiological safety is judged by means of microbiological criteria. Such criteria should, in the context of the WTO/SPS measures, be scientifically justified, and established according to the principles described by the Codex Alimentarius. However, microbiological testing is not a very reliable tool for consumer protection; the emphasis is currently shifting to the application of food safety management tools such as the Hazard Analysis Critical Control Point system (HACCP).

Food Contamination↗
PubMed2000

The roots of microbiology and the influence of Ferdinand Cohn on microbiology of the 19th century.

The beginning of modern microbiology can be traced back to the 1870s, and it was based on the development of new concepts that originated during the two preceding centuries on the role of microorganisms, new experimental methods, and discoveries in chemistry, physics, and evolutionary cell biology. The crucial progress was the isolation and growth on solid media of clone cultures arising from single cells and the demonstration that these pure cultures have specific, inheritable characteristics and metabolic capacities. The doctrine of the spontaneous generation of microorganisms, which stimulated research for a century, lost its role as an important concept. Microorganisms were discovered to be causative agents of infectious diseases and of specific metabolic processes. Microscopy techniques advanced studies on microorganisms. The discovery of sexuality and development in microorganisms and Darwin's theory of evolution contributed to the founding of microbiology as a science. Ferdinand Cohn (1828-1898), a pioneer in the developmental biology of lower plants, considerably promoted the taxonomy and physiology of bacteria, discovered the heat-resistant endospores of bacilli, and was active in applied microbiology.

Bacteria↗
PubMed2006

Combined use of microbiological and non-microbiological data to assess treatment efficacy.

The treatment efficacy for reducing Campylobacter concentrations by a drinking water treatment plant was assessed using a stochastic Monte Carlo model. The goal of the study was to reduce uncertainty of the results by combining microbiological and non-microbiological data in an advanced treatment assessment. Combining raw water Campylobacter and E. coli data reduced the uncertainty on raw water (peak) concentrations five-fold. Similar improvement was achieved for rapid sand filtration. Ozone disinfection was modelled based on ozone concentrations, contact time and temperature. Since this data was available, whereas most microbiological analyses at this point were negative, uncertainty was reduced three-fold. The slow sand filtration assessment could not be improved; however, since previous steps contained less uncertainty, this did not increase uncertainty by much. The study showed that using appropriate data for each treatment step can greatly reduce uncertainty in treatment assessment.

Campylobacter↗
PubMed2001

Microbiological contamination in genetically modified animals and proposals for a microbiological test standard for national universities in Japan.

The Biosafety Committee of the Japanese Association of Laboratory Animal Facilities of National Universities (JALAN) investigated recent episodes of microbiological contamination in genetically modified mice (GMM), and the countermeasures taken when the contaminated GMM were introduced into animal facilities, by questionnaires addressed to 53 animal facilities belonging to JALAN and serological tests. Although almost all of the contaminated GMM were accepted with conditions such as rederivation after or before reception and housing in designated rooms, contamination with a spectrum of microorganisms was demonstrated in GMM transferred domestically and from abroad. In serological tests, Mycoplasma pulmonis, mouse parvovirus, and mouse encephalomylitis virus were detected in GMM transferred from domestic facilities and from abroad. The present results of the questionnaires and serological tests suggest that GMM are highly and widely contaminated with microorganisms compared with mice from commercial breeders. Thus, we propose a microbiological requirement, including microbiological status--excellent, common, and minimum--as a guide for the transfer and procurement of mice and rats in Japan.

Animals↗
PubMed2004

Development of a novel approach for secondary modelling in predictive microbiology: incorporation of microbiological knowledge in black box polynomial modelling.

This research deals with the development of a novel secondary modelling procedure within the framework of predictive microbiology. The procedure consists of three steps: (i) careful formulation of the available microbiological information, both from literature and from the experimental case study at hand, (ii) translation of these requirements in mathematical terms under the form of partial derivatives throughout the complete interpolation region of the experimental design, and (iii) determination of parameter values with suitable optimisation techniques for a flexible black box modelling approach, e.g., a polynomial model or an artificial neural network model. As a vehicle for this procedure, the description of the maximum specific growth rate of Lactobacillus sakei in modified BHI-broth as influenced by suboptimal temperature, water activity, sodium lactate and dissolved carbon dioxide concentration is under study. The procedure results in a constrained polynomial model with excellent descriptive and interpolating features in comparison with an extended Ratkowsky-type model and classical polynomial model, by combining specific properties of both model types. The developed procedure is illustrated on the description of the lag phase as well. It is stressed how the confrontation with experimental data is very important to appreciate the descriptive and interpolating capacities of new or existing models, which is nowadays not always carefully performed. Alternatively, the first two steps of the novel procedure can be used as a tool to demonstrate clearly (possible) interpolative shortcomings of an existing model with straightforward spreadsheet calculations.

Carbon Dioxide↗
PubMedDate not supplied

A simple and inexpensive method for investigating microbiological, enzymatic, or inorganic catalysis using standard histology and microbiology laboratory equipment: assembly, mass transfer properties, hydrodynamic conditions and evaluation.

We introduce a generic, simple, and inexpensive method for performing microbiological, enzymatic, or inorganic catalysis with solids using standard histology and microbiology laboratory equipment. Histology cassettes were used to standardize hydrodynamic conditions and to protect the catalysts and their solid supports. Histology cassettes have the following advantages: they are readily available, inexpensive, solvent and acid resistant, automatable, and the slots in the cassette walls allow liquid to circulate freely. Standard Erlenmeyer flasks were used as reaction vessels. We developed a new camera to observe the movement and position of the histology cassettes as well as the liquid in the Erlenmeyer flasks. The camera produces a stable image of the rotating liquid in the Erlenmeyer flask. This visualization method revealed that in a 250 ml Erlenmeyer flask, stable operating conditions are achieved at a shaking frequency of 300 rpm and a fill volume of 30 ml. In vessels with vertical walls, such as beakers or laboratory bottles, the movement of the histology cassette is not reproducible. Mass transfer characterization using a biological model system and the chemical sulfite-oxidation method revealed that the histology cassette does not influence gas-liquid mass transfer.

Catalysis↗
PubMed1991

[Microbiology of periodontitis. 2. Microbiological diagnosis of periodontitis].

By common methods like scaling and root planing, flap procedures or surgical furcation treatment, a successful therapy of periodontal disease is possible in about 90% of the cases. The remaining 10%, mainly patients with juvenile or rapidly progressive periodontitis, are causing great problems, due to poor treatment response and frequent, local or general recidives. In the future, microbiological tests for a precise diagnosis of the pocket flora will be used in the dental office. They can provide better indications for additional antibiotic therapy. The present article reviews several microbiological investigation methods and their future use in the office during periodontal treatment.

Aggressive Periodontitis↗
PubMed2001

The clinical relevance of microbiologic testing: a comparative analysis of microbiologic samples secured from the same sites and cultured in two independent laboratories.

A field study using five different private periodontal practices was conducted; it compared two microbiologic culture samples simultaneously secured from the same sites within 23 individual patients and submitted for bacterial identification and antibiotic sensitivity testing to two separate laboratories. The results from the two laboratories were often different. In no instance did both laboratories agree on the presence of identical bacterial species. When only bacteria above threshold levels were compared, agreement was found in only nine of 23 cases. When examining antibiotic sensitivity, using 100% kill of all tested pathogens as the ideal, agreement between the two laboratories was poor. The laboratories agreed on the use of amoxicillin 17% of the time, tetracycline 26% of the time, and metronidazole 48% of the time. The use of amoxicillin and metronidazole in combination yielded a 78% agreement when the results of both laboratories were combined. It would appear from the data that the empirical use of amoxicillin-metronidazole combination therapy may be more clinically sound and cost effective than culturing and antibiotic selection based on the results of culture from any single microbiologic testing laboratory.

Adult↗