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PubMed2000

[Microbiological monitoring in neonatal intensive care].

There is no "ideal" method of infection diseases control, but there are some different methods according to the risk degree of patient, the problems, the information accuracy and also the available resources. Some important points need to be stressed about infectious diseases control in Neonatal Intensive Care Unit:--continuous microbiological surveillance in Neonatal Intensive Care Unit is necessary, because newborns admitted are at very high risk of infection disease;--continuous microbiological data review is needed: therefore criticism and integration with other clinical and laboratory data are necessary to exclude simple colonisation;--critical analysis of data allows more rational use of antimicrobical agents to avoid the selection of multiresistant bacteric streams;--a rational analysis of laboratory data needs necessarily a strict collaboration among neonatologists, microbiologists and the Committee for infectious diseases control;--in epidemics, techniques of bacterial streams typization are needed, and methods of molecular biology (DNA and proteins analysis) are better;--this implies a collection of microbiological data, by database integrating microbiological, clinical and anamnestic data and allowing retrospective studies too.

Cross Infection↗
PubMed1996

A microbiological and clinical study of the safety and efficacy of baking-soda dentifrices.

This article reports the results of a study that examined the clinical and microbiological changes associated with regular use of baking-soda dentifrices. Two dentifrice formulations were examined in a 6-month longitudinal study of 101 adult subjects with assessments for plaque, gingival inflammation, and stain at baseline and 3 and 6 months during the active phase of the study, and at 3 months after cessation of product use. One dentifrice contained 52% baking soda and 3% sodium percarbonate (Arm & Hammer PeroxiCare) while the other dentifrice contained 65% baking soda (Arm & Hammer Dental Care). Both dentifrices resulted in statistically significant reductions in dental plaque, gingival inflammation, and stain at all time periods compared to baseline. Dental plaque and buccal soft-tissue samples were obtained for microbiological analysis from a 50-subject subset. Microbiological assays, including bacterial culture, phase-contrast microscopy, and immunofluorescence microscopy, confirmed the safety of both formulations. Beneficial alterations in dental plaque bacteria were noted, including significant reductions in the levels of Actinomyces species. The data from this study indicate that dentifrices containing high levels of baking soda are clinically effective and microbiologically safe.

Actinomyces↗
PubMed1979

Equivalence of microbiological and hydroxylamine methods of analysis for ampicillin dosage forms.

Ampicillin formulations were assayed by microbiological and hydroxylamine methods to determine whether thehydroxylamine analytical method is a suitable substitute for the microbiological method. Paired assay results by the 2 analytical methods were obtained on different strengths of tablet, capsule, and suspension, formulations containing ampicillin and ampicillin degradation compounds. Several statistical tests were used to assess the equivalence of the paired assay results. The data analyses indicate that the hydroxylamine method is a suitable substitute for the microbiological method for potency assays and stability studies of ampicillin formulations. The hydroxylamine method yielded slightly higher assay results than the microbiological method for severely degraded formulations.

Ampicillin↗
PubMed1997

A microbiological and clinical study of the safety and efficacy of baking-soda dentifrices.

This article reports the results of a study that examined the clinical and microbiological changes associated with regular use of baking-soda dentifrices. Two dentifrice formulations were examined in a 6-month longitudinal study of 101 adult subjects with assessments for plaque, gingival inflammation, and stain at baseline and 3 and 6 months during the active phase of the study, and at 3 months after cessation of product use. One dentifrice contained 52% baking soda and 3% sodium percarbonate (Arm & Hammer PeroxiCare) while the other dentifrice contained 65% baking soda (Arm & Hammer Dental Care). Both dentifrices resulted in statistically significant reductions in dental plaque, gingival inflammation, and stain at all time periods compared to baseline. Dental plaque and buccal soft-tissue samples were obtained for microbiological analysis from a 50-subject subset. Microbiological assays, including bacterial culture, phase-contrast microscopy, and immunofluorescence microscopy, confirmed the safety of both formulations. Beneficial alterations in dental plaque bacteria were noted, including significant reductions in the levels of Actinomyces species. The data from this study indicate that dentifrices containing high levels of baking soda are clinically effective and microbiologically safe.

Adolescent↗
PubMed2003

[Microbiological and serological diagnostic methods to detect intrauterine and perinatal infections].

Due to the revolutional development in sampling devices, transport media, automated equipments, microvolume probes and molecular microbiological techniques in the last decade new possibilities have become available for diagnosing microbiologically congenital infections in both the mother and the foetus and the newborn. This minireview gives an insight into the diagnostic tuls of clinical microbiology and infection serology by showing laboratory diagnostic processes of most frequent protozoal, viral and bacterial infections step-by-step. It exhibit an almost complete list of transplacental, intrauterinal and connatal infections. Attention is also focused to the complexity of the interrelationship between the clinical microbiology and infection serology data concerning the infections of the mother and her offspring.

Antibodies, Bacterial↗
PubMed2004

[Microbiological testing of the artificial gingival margin in dentures].

In everyday practice dental laboratories try to reproduce the natural form of sulcus gingivae at the transitional area between artificial teeth and gingiva of removable dentures, even on esthetically less important areas. Aim of these investigations were to examine how artificial recreation of the sulcus gingivae influences plaque retention, and what is the microbiological relevance of these. Investigations were carried out on the vestibular side of removable dentures of 32 randomly selected patients treated at the Department of Prosthodontics at the Faculty of Dentistry, Semmelweis University. Microbiological samples were taken from each patient using the same method. Samples were taken from the left upper first molars' artificial gingival margin using sterile paper points. Paper points were then transported in Eppendorf-tubes, in 2 ml of physiological saline solution, and processed within a two-hour period of time. Series dilutions were made of the sample solutions, then surface-streaked on Subaraud and Gentamycin, blood-agar, eosin-methylene blue and Mitis Salivarius culture enriched with Bacitracin. Subaraud culture was induced under aerob conditions, at room temperature for two days, then the total amount of fungi quantified. After pure-culturing Candida albicans ID-culture was used for identification, and BioMerieux ATB automatic equipment to identify different Candida species. From pure cultures identification was carried out with Gram-staining, Neisser-staining, catalase, oxidase and also with other biochemical reactions. Blood-agar was used to determine total germ count, and normal commensal pharyngeal and oral bacteria. After collecting the microbiological samples, the conventional shape of the dental margin of gingiva was abolished on one side of the dentures and a smooth transition was created between denture teeth and the artificial gingiva in the molar and premolar region. During our investigations only blastomycetes were found. Besides most common Candida albicans, Candida glabrata, tropicallis, spherica and lambica were also identified. Our patients did not miss artificial sulcus gingivae, had no aesthetic complaints about smooth transition between artificial teeth and gingiva. Microbiological investigations of the samples and the comparative analysis showed, that on the smooth transitional areas compared to conventionally shaped sulci significantly less gram-negative, gram-positive bacteria and oral fungi were found, and there was no plaque formation.

Candida↗
PubMed2004

Efficacy of three microbiological monitoring methods in a ventilated cage rack.

The use of individually ventilated caging (IVC) to house mice presents new challenges for effective microbiological monitoring. Methods that exploit the characteristics of IVC have been developed, but to the authors' knowledge, their efficacy has not been systematically investigated. Air exhausted from the IVC rack can be monitored, using sentinels housed in cages that receive rack exhaust air as their supply air, or using filters placed on the exhaust air port. To aid laboratory animal personnel in making informed decisions about effective methods for microbiological monitoring of mice in IVC, the efficacy of air monitoring methods was compared with that of contact and soiled bedding sentinel monitoring. Mice were infected with mouse hepatitis virus (MHV), mouse parvovirus (MPV), murine rotavirus (agent of epizootic diarrhea of mice [EDIM]), Sendai virus (SV), or Helicobacter spp. All agents were detected using contact sentinels. Mouse hepatitis virus was effectively detected in air and soiled bedding sentinels, and SV was detected in air sentinels only. Mouse parvovirus and Helicobacter spp. were transmitted in soiled bedding, but the efficacy of transfer was dependent on the frequency and dilution of soiled bedding transferred. Results were similar when the IVC rack was operated under positive or negative air pressure. Filters were more effective at detecting MHV and SV than they were at detecting MPV. Exposure of sentinels or filters to exhaust air was effective at detecting several infectious agents, and use of these methods could increase the efficacy of microbiological monitoring programs, especially if used with soiled bedding sentinels. In contemporary mouse colonies, a multi-faceted approach to microbiological monitoring is recommended.

Air Pressure↗
PubMed2003

The effect of container-biofilm on the microbiological quality of water used from plastic household containers.

Studies in Southern Africa have shown that even when microbiologically safe water is supplied to developing communities at communal standpipes, contamination by high numbers of pathogenic microorganisms may occur during the processes of fetching water from the supply source and storage during use at home, rendering such waters unsafe for human consumption. This study investigated the occurrence of biofilm in PVC storage containers as one possible reason for this deterioration, using heterotrophic bacteria and total coliform counts as well as turbidity as indicators. A second objective was to determine whether biofilm in water-storage containers could contribute to hazardous microbiological contamination indicated by Escherichia coli and Clostridium perfringens. Results indicated that increased microbiological contamination is associated with biofilm. The biofilm harbours heterotrophic bacteria, total coliforms and C. perfringens. E. coli could not be associated directly with the levels of biofilm in containers but rather appears to be introduced intermittently from the ambient domestic environment. When dislodged with the biofilm, these bacteria contributed substantially to the deterioration of the microbiological quality of supplied water stored in plastic containers.

Biofilms↗
PubMed2004

[Microbiological findings in children with an indwelling central venous catheter].

INTRODUCTION: Besides their obvious advantages for the patient, central venous catheters (CVC) also carry the risk of possible infectious complications. The purpose of our investigation was to carry out a microbiological evaluation of a 5-year set of paediatric patients with indwelling CVCs. PATIENTS AND METHODS: In the group were 218 CVCs inserted to 165 children over a period of 5 years. There were 26 multi-lumen catheters (11.927 %) and 192 single-lumen catheters (88.073 %). The mean indwelling period was 10.1 days per 1 CVC. Blood for microbiology was removed by a physician from the CVC after disinfecting its opening under standard sterile conditions into a commercial sampling vessel HEMOD (Imuna, Sarisske Michalany, Slovak Republic) or into a vessel of an automated haemoculture system BactecPeds PLUS/F (Becton Dickinson and Comp., Spark,MA, USA). When removing the tip of the CVC we disinfected, before removing the CVC, the area around the insertion with isopropyl or ethyl alcohol. We released the fixed CVC and 1 minute after disinfection we pulled out the CVC and cut off the end or rather the tip of the catheter (approx. 1-3 cm of the tip) into a sterile test tube. To establish the diagnosis of infectious complications we used the 1995 Sirges-Serra classification and the CDC criteria. RESULTS: In 5 years (1995-1999) we had 71 infectious complications. There were 31 contaminated catheters, 27 cases of catheter sepsis and 11 cases of catheter bacteraemia. With 147 catheters (67.43%) there were no infectious complications. Dominant microbes were Staphylococcus epidermidis (32 cases - 11 from haemocultures and 21 from CVCs) and Candida spp. (30 cases, 17 from haemocultures and 13 from CVCs). Among the microbiological agents of catheter sepsis predominated Gram-negative bacteria. Out of the whole analysed group 41 children (24.8 %) died. CVC as the cause of death was demonstrated in 6 children (3.636 % of patients with CVC). CONCLUSIONS: Microbiological findings in our group are in line with literary data. To reduce the incidence of infectious complications it is important to limit sampling from CVC to a minimum. Insertion of CVCs under strict sterile conditions and aseptic handling of all entries into the central bloodstream reduces to a minimum the risk of infectious complications.

Bacteremia↗
PubMed2005

The microbiology of ventilator-associated pneumonia.

Ventilator-associated pneumonia (VAP) is a common complication of ventilatory support for patients with acute respiratory failure and is associated with increased morbidity, mortality, and costs. Awareness of the microbiology of VAP is essential for selecting optimal antibiotic therapy and improving these outcomes. The specific microbial causes of VAP are many and varied. Most cases of VAP are caused by bacterial pathogens that normally colonize the oropharynx and gut, or that are acquired via transmission by health-care workers from environmental surfaces or from other patients. Common pathogens include Pseudomonas species and other highly resistant Gram-negative bacilli, staphylococci, the Enterobacteriaceae, streptococci, and Haemophilus species. Antibiotic-resistant pathogens such as Pseudomonas and Acinetobacter species and methicillin-resistant strains of Staphylococcus aureus are much more common after prior antibiotic treatment or prolonged hospitalization or mechanical ventilation, and when other risk factors are present. The bacterial pathogens responsible for VAP also vary depending on patient characteristics and in certain clinical circumstances, such as in acute respiratory distress syndrome or following tracheostomy, traumatic injuries, or burns. But these differences appear to be due primarily to the duration of mechanical ventilation and/or degree of prior antibiotic exposure of these patients. The causes of VAP can vary considerably by geographic location (even between units in the same hospital), emphasizing the importance of local epidemiological and microbiological data. Atypical bacteria, viruses, and fungi also have been implicated as causes of VAP, but these pathogens have not been studied systematically and their role is presently unclear. In conclusion, information about the microbiology of VAP serves to guide optimal antibiotic therapy. The risk of antibiotic-resistant pathogens can be estimated using simple clinical features and awareness of local microbiology patterns. The roles of atypical bacterial and nonbacterial pathogens in VAP are incompletely understood and should be investigated further.

Anti-Bacterial Agents↗
PubMed1989

[Incidence of nosocomial infections. Comparison of 2 surveillance systems: clinical vs microbiological follow-up].

The effectiveness of a clinical and a microbiological follow-up systems for the detection of hospital-acquired infection (HI), both independently and simultaneously applied, were prospectively evaluated. The observed incidence rate was 11.4%. The clinical follow-up detected 81.3% of HI while microbiological follow-up detected 59.7%. This difference was statistically significant (p less than 0.001). It took 43 and 45 minutes to detect each instance of HI with the clinical and microbiological methods, respectively. Clinical methods are the most adequate to obtain maximal sensitivity in the overall surveillance of hospital-acquired infection, whereas microbiological follow-up may be useful for the detection of some types of HI such as bacteremia or urinary tract infection.

Cohort Studies↗
PubMed1984

Microbiology for orthopaedic surgeons: selected aspects.

The treatment and prevention of orthopedic sepsis is based on the principles of any surgical sepsis and the factors that influence the chronicity of infection and microbiology. In the past, the field of orthopedic sepsis has been neglected and has retained the methodologies of previous years without a sharp focus on the principles and pathophysiology of infectious disease. Over the last ten years there has been an increasing interest in orthopedic sepsis along with significant changes in our concepts of antibiotics, principles of treatment, and microbiology. In this article the authors hope to identify the practical uses of clinical microbiology in diagnosing and managing orthopedic infections. The surgeon can use microbiologic techniques in many ways: (a) to determine sterility of wounds, (b) to detect the presence of infection, (c) to estimate the timing of primary closure of acute and chronic wounds and the application of skin grafts, and (d) as guides for the surgeon and infectious disease physician in the choice of appropriate antibiotics.

Anti-Bacterial Agents↗
PubMed1980

Comparison of metronidazole assay by microbiological and chemical methods.

Chemical (thin layer chromatography/fluorescence quenching in situ) and microbiological (agar well, diffusion technique with Clostridium perfringens as indicator strain) methods of assaying metronidazole have been compared. On dummy samples made with pure metronidazole in pooled human serum, both methods had a coefficient of variation ranging from 5.5 to 9.6 per cent of the mean. The microbiological method slightly underestimated the real amounts, and also had lower values than the chemical procedure. Comparison of serum and urine samples taken during the early, middle and late periods after medication to volunteers showed that biotransformation to antibacterially active metabolites contributes significantly to the antibacterial activity, particularly in urine. Biotransformation explains why microbiologically determined concentrations were higher than those determined chemically in samples taken at least 16-20 hours after intake of tablets or suppositories. It is important to be aware of the circumstance that the results of microbiological assay are sensu strictu limited to the particular indicator strain used, since other bacteria may exhibit other patterns of sensitivity to metronidazole and its metabolites.

Biological Assay↗
PubMed1983

[Microbiological analysis of the ejaculate in andrology].

Microbiological analysis of semen in andrology is mainly performed in cases of infertility and artificial insemination. In order to localize the suggested infection and to detect urethral (asymptomatic) colonization, we recommend to analyse additional specimens of the patient, i.e. urethral swabs and first portion of urine. As a rule, quantitative microbiological analysis is necessary in cases of bacteria belonging to the group of potentially pathogenic flora. In isolating pathogenic ("specific") bacteria, the detection of a few microorganisms indicates an infectious process. We recommend the careful microscopical examination of the ejaculate to detect phagocytes, abnormal spermatozoa, trichomonads, yeasts and other cells. As a rapid microscopical examination we employ the DAPI-fluorochrome-technique. Microbiological cultures should take into consideration the isolation and identification of ureaplasmas and chlamydia trachomatis. In order to achieve a comparison of microbiological results with those of other laboratories, it is essential to define the terms "significant bacteriospermia" and "significant leukocytospermia". In other words, it is necessary to introduce a borderline between contamination and infection concerning the "nonspecific" potentially pathogenic flora.

Bacteriological Techniques↗
PubMed1981

Comparison of an immunoassay and a microbiological assay for tobramycin serum concentrations.

An enzyme multiplied immunoassay technique (EMIT) and a microbiological assay were compared as methods for determining the concentration of tobramycin in human serum. Tobramycin sulfate in various concentrations (0.4-20.0 microgram/ml) was dissolved in lyophilized human serum. Tobramycin concentration was determined by EMIT assay and a microbiological agar diffusion assay using Bacillus subtilis ATCC 6633 as the test organism. Serum samples of 162 patients who received tobramycin 60 mg i.m. were also assayed by the two methods. The effect of six antibiotics on the determination of tobramycin concentration by EMIT assay was measured. To test whether freezing affects tobramycin concentration measured by EMIT assay, tobramycin in five concentrations in lyophilized human serum were frozen and analyzed at weekly intervals for seven weeks. The concentration of tobramycin determined by EMIT assay and microbiological assay in both lyophilized human serum and patient samples were highly correlated (r = 0.994 and 0.949) respectively). Dibekacin, an aminoglycoside structurally similar to tobramycin, interfered with the determination of tobramycin concentration. No effect of freezing was observed. The results of this study show that EMIT assay is an acceptable method for routine laboratory analysis of tobramycin serum concentration. It is as accurate as the microbiological assay tested.

Anti-Bacterial Agents↗
PubMed1993

[Sterilization--the microbiology between claim and reality].

Sterilization means to free an object from all living and viable germs. To fulfill this claim, the microbiology is confronted with some fundamental problems. Under the action of a microbicidal agent the microorganisms do not die at the same time, even if there is a homogeneous population. The destruction of microorganisms follows a special destruction order. The number of dying organisms is always proportional to the number of viable organisms present. On theoretical grounds it is, therefore, impossible to free an object from all living and viable germs; there will ever be left a certain proportion of viable germs, even if this proportion may be very small. The aim of sterilization must be to keep that proportion very small. To reach this goal in a practical time without damaging the objects to be sterilized, microorganisms of high resistance should be excluded, i.e. the objects to be sterilized should not be contaminated by microorganisms of high resistance to the sterilizing agent(s). The assurance level that an object is free from all living and viable germs must be so high that it is practically impossible to proof this by a test for sterility. On the other hand, the absence of microorganisms of high resistance in the objects to be sterilized makes it feasible to use microorganisms of high resistance as test organisms for the manufacture of microbiologic indicators. Such indicators enable to record as an integral the action of all microbicidal parameters of the noxious agent(s) far beyond the region for which the application of a test for sterility is sensible. Nevertheless, bioindicators have a similar status as the physical and physico-chemical controlling instruments. Microbiological indicators make it possible to guarantee the application of a certain (minimal) efficacy of the microbicidal agent(s). Whether this efficacy is sufficient to reach the wanted sterility assurance level depends, last not least, on the microbiological contamination (bioburden) of the object to be sterilized. Each sterilization process has its own prerequisites.

Anti-Bacterial Agents↗
PubMedDate not supplied

Assay of oxytetracycline in animal feed by liquid chromatography and microbiological plate assay.

In a proposed method for determining oxytetracycline (OTC) in animal feed, OTC is extracted with acidic methanol, and the extract is centrifuged and assayed by microbiological plate assay and by reversed-phase liquid chromatography (LC). Riboflavin and furazolidone elute at retention times similar to that of OTC. Successful separations are made by using both dimethylformamide and acetonitrile mobile phases. Variation between microbiological and LC results is comparable with variation within the microbiological assay. The relative standard deviation for 6 replicates of feed at the 100 ppm level is 3.6% for the LC assay and 3.1% for the microbiological assay.

Animal Feed↗
PubMed1977

A radiometric microbiologic method for vitamin B12 assay.

A radiometric microbiologic method was developed for assaying vitamin B12 in human serum. In the presence of 14C-arginine and cyanocobalamin, Lactobacillus leichmannii produced significant amounts of 14CO2 within 16-20 hr. The amount of 14CO2 evolved was optimized with the use of guanido-labeled arginine and is proportional to the amount of cyanoco-balamin added. The method gave satisfactory recovery of added vitamin B12 to sera, and it gave values comparable to the standard microbiologic (turbidimetric) method using L. leichmannii. The radiometric microbiologic method allowed elimination of several steps considered essential in the standard microbiologic methods: (A) Extraction of vitamin B12 bound to serum proteins could be accomplished in one autoclaving step with the assay medium at 15 psi for 3-5 min; (B) The precipitated serum proteins did not need to be separated, since they do not interfere with this assay,

Arginine↗