We studied the disinfection effect of a new ultraviolet (UV) sterilizer and its utilization on ultrasound probe surfaces. Carrier quantitative germicidal tests, simulated on-the-spot trials, and organic substance influence tests were used to carry out experimental observation. Artificially infected probes were disinfected using the sterilizer or a germicidal lamp for comparison. The total number and types of bacteria were determined and identified. Our results demonstrated the sterilizer had the best disinfection effect among three different disinfection methods in hospital. The sterilizer has been used in a hospital setting for 2 years with no notable damage to the ultrasound probe instrument. It has the advantages of fast disinfection, high disinfection effect, and good compatibility with the ultrasound instrument, worthy of being a promoted application in medical institutions.
Bacterial Infections ; microbiology ; prevention & control ; Colony Count, Microbial ; Cross Infection ; microbiology ; prevention & control ; Disinfection ; instrumentation ; methods ; Equipment Contamination ; prevention & control ; Sterilization ; instrumentation ; Surface Properties ; Ultrasonography ; instrumentation ; Ultraviolet Rays

Bacterial infection associated with the use of medical or dental devices is a serious concern. Although devices made of ethylene vinyl acetate (EVA) are often used in the oral cavity, there are no established standards for their storage. We investigated bacterial survival on EVA sheets under various storage conditions to establish a standard for hygienic storage of such dental devices. Bacterial counts were evaluated, which showed a significant decrease after washing with sterilized water, mechanical brushing and rinsing, and using Mouthguard Cleaner as compared to untreated samples. In addition, no bacteria were detected on samples stored 2 days or longer in a ventilated environment, whereas they were detected for up to 14 days on samples without any cleaning stored in a closed environment. Bacterial counts for the untreated samples gradually declined, while surviving bacteria on samples treated with sterilized water and mechanical brushing showed a rapid decrease. Additionally, bacterial identification using polymerase chain reaction (PCR) revealed that Streptococcus oralis was dominantly detected on salivary samples after 14 days of storage among both two subjects. For effective hygienic storage of dental devices made of EVA, washing with sterilized water is important to remove absorbed salivary compounds along with storage in a ventilated environment.
Adult ; Colony Count, Microbial ; Decontamination ; methods ; Dental Equipment ; microbiology ; Equipment Contamination ; Humans ; Microbial Viability ; Molecular Typing ; Polyvinyls ; Saliva ; microbiology ; Streptococcus ; physiology ; Time Factors ; Water ; Young Adult

OBJECTIVETo conduct a quantitative risk assessment for Listeria monocytogenes in bulk cooked meat products in China.

METHODSThe data on the contamination level of Listeria monocytogenes in cooked meat products was from national foodborne disease surveillance network, involving a total of 841 samples. All the samples were detected by a qualitative method and 97 samples among them were detected using a quantitative method. The intake data of cooked meats was from Chinese National Nutrition and Health Survey in 2002 and population data in the monitoring sites was collected from National Bureau of Statistics in 2008 to estimate the composition of the population of different ages, which would be the base of assessing the probability of listeriosis in the different subpopulations. Using @Risk software to estimate the risk of listeriosis caused by consuming deli meats for different subpopulation (0 - 4 years old, 5 - 64 years old and 65 years and older) by quantitative risk assessments which involved hazard identification, hazard characterization, exposure assessment and risk characterization and conduct sensitivity analysis.

RESULTSThe contamination level of Listeria monocytogenes in the most of samples (96.08%, 808/841) was less than 3 MPN/g (0.5 lg MPN/g), and the average concentration of Listeria monocytogenes was -0.61 lg CFU/g (90%CI: -1.22 - 0.46 lg CFU/g). Estimated servings of cooked meat consumption for 0 - 4, 5 - 64 and 65 years and older were 5.52 × 10(9), 8.99 × 10(10), 1.01 × 10(10), respectively. Estimated number of cases (median) of listeriosis each year per million people caused by consuming cooked meats in young (0 - 4 years old), intermediate age (5 - 64 years old) and elderly (65 years and older) population were 5.53 × 10(-3), 1.72 × 10(-4), 7.57 × 10(-3), respectively. Results of sensitivity analysis showed that contamination level at retail, serving size of cooked meats, storage time at home, storage temperature and ERG at 5°C were positive factors for the risk of listeriosis (r value was 0.607, 0.408, 0.339, 0.259, 0.183 respectively, P < 0.05).

CONCLUSIONCooked meat products in bulk is a risk food, which could cause listeriosis. Contamination level of Listeria monocytogenes in cooked meat products in bulk is the top risk factor for the listeriosis.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Colony Count, Microbial ; Food Contamination ; analysis ; Food Microbiology ; Humans ; Infant ; Listeria monocytogenes ; isolation & purification ; Meat Products ; microbiology ; Middle Aged ; Models, Theoretical ; Risk Assessment ; Software ; Young Adult

Direct observation of a wide range of natural microorganisms has revealed the fact that the majority of microbes persist as surface-attached communities surrounded by matrix materials, called biofilms. Biofilms can be formed by a single bacterial strain. However, most natural biofilms are actually formed by multiple bacterial species. Conventional methods for bacterial cleaning, such as applications of antibiotics and/or disinfectants are often ineffective for biofilm populations due to their special physiology and physical matrix barrier. It has been estimated that billions of dollars are spent every year worldwide to deal with damage to equipment, contaminations of products, energy losses, and infections in human beings resulted from microbial biofilms. Microorganisms compete, cooperate, and communicate with each other in multi-species biofilms. Understanding the mechanisms of multi-species biofilm formation will facilitate the development of methods for combating bacterial biofilms in clinical, environmental, industrial, and agricultural areas. The most recent advances in the understanding of multi-species biofilms are summarized and discussed in the review.
Animals ; Bacterial Adhesion ; physiology ; Bacterial Typing Techniques ; Biofilms ; growth & development ; Environmental Restoration and Remediation ; Equipment Contamination ; Humans ; Microbial Consortia ; genetics ; physiology ; Microbial Interactions ; physiology ; Microscopy, Confocal ; Models, Biological ; Nucleic Acid Hybridization ; Polymerase Chain Reaction ; Polysaccharides, Bacterial ; chemistry

We aimed to know the risk-stratification-based prevalence of bacterial contamination of ambulance vehicle surfaces, equipment, and materials. This study was performed in a metropolitan area with fire-based single-tiered Basic Life Support ambulances. Total 13 out of 117 ambulances (11.1%) were sampled and 33 sites per each ambulance were sampled using a soft rayon swab and aseptic containers. These samples were then plated onto a screening media of blood agar and MacConkey agar. Specific identification with antibiotic susceptibility was performed. We categorized sampling sites into risk stratification-based groups (Critical, Semi-critical, and Non-critical equipment) related to the likelihood of direct contact with patients' mucosa. Total 214 of 429 samples showed positive results (49.9%) for any bacteria. Four of these were pathogenic (0.9%) (MRSA, MRCoNS, and K. pneumoniae), and 210 of these were environmental flora (49.0%). However, the prevalence (positive/number of sample) of bacterial contamination in critical, semi-critical airway, semi-critical breathing apparatus group was as high as 15.4% (4/26), 30.7% (16/52), and 46.2% (48/104), respectively. Despite current formal guidelines, critical and semi-critical equipments were contaminated with pathogens and normal flora. This study suggests the need for strict infection control and prevention for ambulance services.
Adult ; Aged ; *Ambulances ; Bacteria/growth & development/*isolation & purification ; Bacterial Infections/diagnosis ; Emergency Medical Services ; *Equipment Contamination ; Equipment and Supplies/*microbiology ; Female ; Humans ; Infection Control ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Risk Factors

OBJECTIVETo investigate the status of bacterial contamination in the shellfish products in Wenzhou.

METHODSOne hundred samples were collected and their bacterial populations including the total plate count were investigated.

RESULTSOf the 100 samples collected, 67 samples failed to not meet the national regulations due to bacterial contamination, accounting for 67% of the total samples. Among the contaminated samples, the most serious contamination was caused by coliforms (61.4% of the total plate count with contamination), followed by Salmonella (18.6%), Vibio parahaemolyticus (15.7%), Listeria spp. (4.3%) and others (6%).

CONCLUSIONMicrobial pollution has become a threat to the marine shellfish products in Wenzhou.

Animals ; China ; Colony Count, Microbial ; Food Contamination ; Food Microbiology ; Listeria ; isolation & purification ; Salmonella ; isolation & purification ; Shellfish ; microbiology

OBJECTIVETo identify the antimicrobial resistance of commercial lactic acid bacteria present in microbial foods and drug additives by analyzing their isolated strains used for fermentation and probiotics.

METHODSAntimicrobial susceptibility of 41 screened isolates was tested with disc diffusion and E-test methods after species-level identification. Resistant strains were selected and examined for the presence of resistance genes by PCR.

RESULTSDistribution of resistance was found in different species. All isolates were susceptible to chloramphenicol, tetracycline, ampicillin, amoxicillin/clavulanic acid, cephalothin, and imipenem. In addition, isolates resistant to vancomycin, rifampicin, streptomycin, bacitracin, and erythromycin were detected, although the incidence of resistance to these antibiotics was relatively low. In contrast, most strains were resistant to ciprofloxacin, amikacin, trimethoprim/sulphamethoxazole, and gentamycin. The genes msrC, vanX, and dfrA were detected in strains of Enterococcus faecium, Lactobacillus plantarum, Streptococcus thermophilus, and Lactococcus lactis.

CONCLUSIONAntibiotic resistance is present in different species of probiotic strains, which poses a threat to food safety. Evaluation of the safety of lactic acid bacteria for human consumption should be guided by established criteria, guidelines and regulations.

Anti-Bacterial Agents ; pharmacology ; Cultured Milk Products ; microbiology ; Dairy Products ; Drug Contamination ; Drug Resistance, Multiple, Bacterial ; Food Microbiology ; Humans ; Lactobacillaceae ; drug effects ; Microbial Sensitivity Tests ; Pharmaceutical Preparations ; Probiotics

Background: Food-born bacteria can be present in raw materials or contaminated foods during process and storage. Shrimp paste is a popular food in Viet Nam, but there are no studies on the hygiene and safety of this food. Objectives: To identify the microbial contamination of commercial shrimp paste available in Ha Noi City. Materials and method: A total of 50 shrimp paste samples were collected randomly from markets around Ha Noi City. Enumeration and isolation methods were used to determine the microbial contamination in these samples. Results: 100% of the samples were contaminated with Clostridium perfringens and Candida albicans. 10% of samples were contaminated with Coliform. Other pathogenic bacteria, including Escherichia coli, Salmonella, Staphylococcus aureus, Vibrio parahaemolyticus and Vibrio cholerae were not found in shrimp paste samples. Conclusion: Evaluation of microbial contamination in popular foods such as shrimp paste should be done regularly to prevent food-born diseases in the community.
Microbial contamination ; Food safety.

BACKGROUND: We noticed an abrupt increase in the isolation of Stenotrophomonas maltophilia from bronchoalveolar lavage (BAL) specimens collected at Chosun University Hospital. We performed surveillance cultures in order to identify the source of what appeared to be a pseudo-outbreak. METHODS: To investigate a possible nosocomial outbreak of S. maltophilia, we performed culture of 11 environmental specimens obtained from a bronchoscopy room and two bronchoscopes. Pulsedfield gel electrophoresis (PFGE) was used to examine the genetic relatedness among the strains of S. maltophilia recovered from BAL specimens of 3 patients and 1 environmental sample, as well as 9 unrelated strains of S. maltophilia as a control. RESULTS: During a 7 day-period in March 2006, S. maltophilia was isolated from the BAL specimens of 7 of 13 (54%) patients, compared to only 5 of 188 (2.6%) patients during the 6-month period prior to that period. S. maltophilia was isolated from 1 of the 11 environmental samples, which was obtained from a fiberoptic bronchoscope suction channel. All 7 patient isolates and one environmental isolate exhibited similar antibiotic susceptibility patterns. PFGE analysis of the genomic DNA from epidemic strains demonstrated an identical banding pattern, whereas each of epidemiologically unrelated strains showed a unique electrophoretic pattern. CONCLUSIONS: Apparently one of the hospital bronchoscopes became contaminated with S. maltophilia during a bronchoscopic procedure. It is likely that subsequent specimen contamination occurred because the bronchoscope had been inadequately cleaned and disinfected. The pseudo-outbreak was controlled successfully by removing the source of infection.
Aged ; Aged, 80 and over ; Bronchoalveolar Lavage Fluid/microbiology ; Bronchoscopes/*microbiology ; *Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; *Equipment Contamination ; Gram-Negative Bacterial Infections/diagnosis/*epidemiology/transmission ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Stenotrophomonas maltophilia/*genetics/isolation & purification

OBJECTIVEMechanical ventilation support is a very important method for the salvage of serious patients. However, it can result in the formation of an adherent matrix of bacteria on the surfaces of implanted materials which is termed "biofilm". Biofilm is dense bacterial communities attached to a solid surface and surrounded by an exopolysaccharide matrix. One of the most important features of bacterial biofilm is their resistance to antimicrobial agents and host immune system components. As a consequence, diseases involving biofilm are generally chronic and difficult to treat. The present study was conducted to explore the relationship between ETT-biofilm and the lower respiratory infection by observing microbial colonization and associated biofilm accumulation on the surface of endotracheal tubes (ETTs) removed from neonates treated with intubated mechanical ventilation.

METHODSTwenty neonates undergoing mechanical ventilation (from January to June in 2005) were recruited into this study. Clinical data about lower respiratory infection for each case were collected. ETTs were collected at the first time of extubation. A sterile control tube was also processed. For each ETT, a 1-cm-long cross-sectional segment was divided into two portions for both scanning electron microscopy (SEM) and aerobic/anaerobic cultures. The presence of biofilm on the surface of ETTs were examined by SEM, meanwhile, bacteria harvested from the surface of ETTs and the secretions of lower respiratory tract were isolated, identified and assessed on antimicrobial susceptibility, respectively.

RESULTSThe diagnosis on admission of the twenty cases included: neonatal respiratory distress syndrome (10), meconium aspirate syndrome (2), severe asphyxia (2), pneumatothorax (2), severe pneumonia (1), scleredema neonatorum (1), inborn pulmonary hypoplasia (1) and recurrent apnea (1). Thirteen cases did not present symptoms and signs of lower respiratory infection before mechanical ventilation. However, during the mechanical ventilation process, symptoms and signs of lower respiratory infection presented and lasted until extubation. Nine of the above mentioned thirteen cases (70%) had the same duration of tube use as mechanical ventilation duration (mean: 3.6 days). Observation by SEM showed that colonization was time dependent and the incidence of microbial colonization increased when the duration of tube use exceeded one days (12/20). There were no obvious bacterial colonies except that some amorphous material was noted in 5 of 20 ETTs as early as one day of tube use. Up to 2 days of tube use (4/20), attached bacterial colonization was seen embedded in amorphous material (3/4). Up to 3 days (7/20), a layer of biofilm formation presented on ETTs (5/7). Furthermore, biofilm architecture became more mature and complex if the duration exceeded 3 days. Neither bacteria nor biofilm formation was seen on the control ETT. The results of aerobic/anaerobic cultures showed that there were 14 cultures from ETTs (normal flora grew in 4) and 7 pathogens were isolated; 13 cultures from the secretions of lower respiratory tract (normal flora grew in 1) and 10 pathogens were isolated. Seven samples had the same pathogen both on the surface of ETTs and in the secretions of lower respiratory tract, which accounted for 50% of the positive cultures from ETTs, including Xanthomonas maltophilia (2), Klebsiella pneumoniae (2), Acinetobacter lwoffii (1), Acinetobacter baumannii (1) and normal flora (1). The gram-negative bacteria isolated from the surface of ETTs and the secretions of lower respiratory tract presented multi-resistance to antibiotics.

CONCLUSIONSThe ETT-biofilm develops into mature and complex form with the duration of tube use increase. This study provides evidence that there is correlation between microbial colonization, biofilm formation on the surface of ETTs and the lower respiratory infection in neonates who were intubated and ventilated for a prolonged period. ETT-Biofilm could also be a possible source of the recurrent infection. Increased attention must be paid to modification of the ETT to prevent or substantially reduce biofilm formation.

Acinetobacter baumannii ; isolation & purification ; Anti-Bacterial Agents ; adverse effects ; therapeutic use ; Biofilms ; Colony Count, Microbial ; Equipment Contamination ; Female ; Gram-Negative Bacteria ; Humans ; Infant ; Infant, Newborn ; Intubation, Intratracheal ; adverse effects ; Male ; Microscopy, Electron, Scanning ; methods ; Pediatrics ; Pneumonia ; drug therapy ; etiology ; Respiration, Artificial ; adverse effects ; Respiratory Tract Infections ; drug therapy ; etiology ; Trachea ; microbiology