An individual may be at increased risk of acquiring an infectious disease either because of inherent host factors, such as age and illness, or environmental factors, manipulations performed as part of medical practice, or a combination of both factors. Among the exogenaus causes, especially the mode of airborne transmission in hospital infection, the authors observed the effects of UV-254 nm light on air contaminants in the intensive care unit by performing colony counts and Gram stain. The mechanism of action of UV-254 nm light on air contaminants is known to be the destruction of the microbial genetic material such as RNA and/or DNA. The results of reducing the air contaminants through the UV-254 nm light in the intensive care unit show the destruction of a broad spectrum of pathogenic and opportunistic microorganisms as follows: 1) The UV-254 nm light was most effective in crowded conditions of the intensive care unit. 2) The effect was begun from one hour after exposure of the UV-254 nm light device, and low colony counts were maintained constantly up to the 12th day. 3) Among the microorganisms, the device especially reduced the colony counts of staphylococcus species.
Communicable Diseases ; Cross Infection ; DNA ; Genetics, Microbial ; Intensive Care Units ; RNA ; Staphylococcus

Child ; Cross Infection ; microbiology ; Disease Outbreaks ; Humans ; Methicillin-Resistant Staphylococcus aureus ; classification ; drug effects ; genetics

Antibiotic resistance is a major global concern and challenge in the 21st century. Enterobacteriaceae are one of the important pathogens of hospital-acquired infections. With the increasing use of antibiotics in clinical practice, a variety of drug-resistant Enterobacteriaceae, especially multidrug-resistant Enterobacteriaceae have emerged, posing an increasingly serious threat to human health. Bacteria can acquire antibiotic resistance by mutation or horizontal transfer of antibiotic resistance genes, and it is often possible to predict the corresponding resistance phenotype from known mechanism. However, recent findings suggest that genetic background and environmental factors could alter the expression of specific resistance genes and that a given genotype does not always generate the expected resistance phenotype. The genotype-phenotype segregation greatly hampers our ability to predict antibiotic resistance phenotype from a genetic perspective. In this review, we explore the genetic and environmental regulation of the expression of antibiotic resistance genes in a variety of Enterobacteriaceae, with the aim to provide scientific evidence for genetic prediction of antibiotic resistance phenotype and clinical guidance on drug use.
Anti-Bacterial Agents/pharmacology* ; Bacteria ; Cross Infection ; Drug Resistance, Microbial ; Enterobacteriaceae/genetics* ; Humans

OBJECTIVETo study the risk factors of Acinetobacter baummanii in nosocomial infections, and to verify the nature of Acinetobacter baumannii strains isolated from intensive care unit (ICU).

METHODSA hundred and fourty patients associated with nosocomial infection of Acinetobacter baummanii from four teaching hospitals were selected and compared with controls through a case control study to identify risk factors. The strains isolated from the ICU were typed by polymerase chain reaction (PCR) with the primer M(13) following electrophoresis in agarose gel.

RESULTSThe odds ratios (ORs) were: state of the illness (OR = 8.69), using immunosuppressant (OR = 4.85), mechanical ventilation (OR = 3.68) and treatment with 3 kinds of antibiotics (OR = 3.014). Data from PCR studies indicated that these strains were sharing identical band pattern from the five strains.

CONCLUSIONRisk factors for nosocomial infection with Acinetobacter baummanii included state of an illness, immunosuppressant, mechanical ventilation, and treatment with antibiotics. A multidrug-resistant strains of Acinetobacter baumannii was identified in ICU.

Acinetobacter baumannii ; classification ; genetics ; Cross Infection ; etiology ; microbiology ; Genotype ; Humans ; Logistic Models ; Polymerase Chain Reaction ; Risk Factors

OBJECTIVETo identify the etiology of an aseptic encephalitis outbreak (ten cases) in a hospital of Xiamen city from 11 to 17 May, 2011.

METHODSA total of ten patients' throat swabs, anal swabs and cerebrospinal fluid were collected and detected by RT-PCR for pan-enterovirus. The samples containing detectable pan-enterovirus were tested by PCR with genotype-specific general primers located in VP1 region of enterovirus genotype A, B and C (HEV-A, B and C). The PCR products of VP1 segment were purified and sequenced, and phylogenetic analysis was performed. Meanwhile, the pathogens in those samples were isolated in Vero cell culture. Homologous analysis of VP1 sequences were carried out for the cultured virus samples and the original clinical samples to identify the outbreak etiology.

RESULTSAmong the ten cases, seven cases were positive for pan-enterovirus nucleic acid. When tested by genotype-specific PCR, the throat and anal swab samples from those 7 patients were positive with HEV-B VP1 primers. Meanwhile, the HEV-B VP1 segments were sequenced and phylogenetic analyzed, which indicated the seven cases were all infected by enterovirus Echo 30. The sequences from those samples had homology of 95.3% - 97.1% with the epidemic strains in Zhejiang, 2004. Out of the seven cases, the sequences of XM2, XM3, XM4, XM8 throat swab samples and XM3, XM6 throat samples showed 99.4% - 100.0% homology which were different from the sequence of XM1, and the homology was 92.8% - 93.4%. Furthermore, the viruses were isolated using Vero cells from XM1, XM2, XM3, XM4 and XM8 throat swab samples, and the VP1 sequence showed more than 99.9% homology with the original specimens.

CONCLUSIONThe local outbreak of aseptic encephalitis was caused by Echo 30 of enterovirus genotype B, and the epidemic strains may have different genetic background.

Child, Preschool ; China ; epidemiology ; Cross Infection ; epidemiology ; virology ; Disease Outbreaks ; Encephalitis ; epidemiology ; virology ; Enterovirus ; genetics ; Enterovirus B, Human ; genetics ; Female ; Genotype ; Humans ; Male ; Molecular Sequence Data

OBJECTIVETo analyze the drug resistance and drug resistance genes of imipenem-resistant Pseudomonas aeruginosa (IRPA) strains isolated from burn wards.

METHODSFrom June 2011 to June 2012, 30 strains of IRPA were isolated from wound excretion, sputum, and venous catheter attachment from burn patients hospitalized in Guangzhou Hospital of Integrated Traditional Chinese and Western Medicine. Drug resistance of the IRPA to 12 antibiotics commonly used in clinic, including ceftazidime, amikacin, ciprofloxacin, etc., was tested with K-B paper agar disk diffusion method. Metallo-β-lactamase (MBL)-producing IRPA was detected by synergism test with imipenem-2-mercaptoethanol. Plasmid of IRPA was extracted, and it was inserted into competent cells, producing transformation strains (TSs). Drug resistance of TSs to imipenem and the MBL-producing TSs were detected. The genes blaIMP, blaVIM, blaOXA-1, blaOXA-2 and blaOXA-10 of IRPA and the TSs were detected by polymerase chain reaction. The drug resistance of IRPA producing MBL or OXA enzyme was summed up.

RESULTSThe sensitive rates of the 30 strains of IRPA to the 12 antibiotics were equal to or above 60.0%. Six strains of MBL-producing IRPA were screened. Twenty-four TSs were resistant to imipenem, and 6 strains among them were MBL-producing positive. Among the 30 strains of IRPA, 6 strains and their corresponding TSs carried blaVIM; 20 strains and their corresponding TSs carried blaOXA-10; no strain was detected to carry blaIMP, blaOXA-1 or blaOXA-2. Two strains and their corresponding TSs were detected carrying both blaVIM and blaOXA-10. No significant difference of drug resistance was observed between strains producing only MBL or OXA enzyme, with the same high resistance to β-lactam antibiotics and some degree of sensitivity to aminoglycoside antibiotics. Strains producing enzymes MBL and OXA were all resistant to the 12 antibiotics.

CONCLUSIONSIRPA strains isolated from burn wards of Guangzhou Hospital of Integrated Traditional Chinese and Western Medicine are multidrug-resistant, and they mainly produce type B and D carbapenemases.

Burns ; microbiology ; Cross Infection ; microbiology ; Drug Resistance, Multiple, Bacterial ; genetics ; Humans ; Imipenem ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa ; drug effects ; genetics ; isolation & purification

OBJECTIVETo study the mode of transmission and molecular characteristics on carbapenem-resistant Acinetobacter baumannii strain. Strains were isolated from different parts of samples in various patients.

METHODSClinical information of carbapenem-resistant Acinetobacter baumannii isolates were stored and analyzed by WHONET 5.4 software. The transmission and pathopoiesis of the strains were learned through case file review. Genotypes of isolates were identified by pulse-field gel electrophoresis (PFGE) and genes of carbapenemase were detected by multiple PCR, in order to find molecular characteristics and relatedness between strains.

RESULTS29 stains of Acinetobacter baumannii resistant to carbapenem were isolated from 2 or more kinds of samples among 13 patients'. Two genotypes were identified by PFGE: genotype A was obtained from 22 isolates in 11 patients and genotype B was obtained from 7 isolates in 4 patients. PCR amplification showed that all strains possessed OXA-23 gene except 1, and all strains possessed Integrase gene I except 3.

CONCLUSIONThere were 2 different genotypes from 29 strains of carbapenem-resistant Acinetobacter baumannii with Genotype A as the main type. OXA-23 carbapenemase gene and integrase gene I were detected from most of the isolates. All the strains could be easily transmitted in the body of the patients and among patients, hence becoming the epidemic pathogen of iatrogenic infection.

Acinetobacter Infections ; microbiology ; transmission ; Acinetobacter baumannii ; classification ; drug effects ; genetics ; Carbapenems ; pharmacology ; Cross Infection ; microbiology ; transmission ; Drug Resistance, Bacterial ; genetics ; Genotype ; Humans

To characterize rotavirus G and P genotypes circulating among infants and young children hospitalized with severe diarrhea in a university hospital in Gyeonggi province, Korea, and to examine any association of the genotypes and nosocomial infections, we genotyped 103 isolates of rotavirus by multiplex RT-PCR. In July 2001-June 2002, we found that globally common strains constituted 64.2% (G2P[4] 28.3%, G3P[8] 28.3%, G4P[8] 5.7%, and G1P[8] 1.9%), and the uncommon strain, G4P[6], constituted 26.4%. During July 2002-June 2003, the percentage of common strains decreased to 44.0% (G3P[8] 18.0%, G2P[4] 16.8%, and G1P[8] 10.0%), but G4P[6] increased to 36.0%. G9P[8] was identified in 10.0% of cases, and thus can be considered an emerging strain in Korea. Eight-eight percent of G4P[6] was isolated from newborn babies. Among the 103 patients, there was an evidence of nosocomial rotavirus infection in 23 children (22.3%). Of these, 19 (82.6%) were newborns infected with G4P[6] strains of rotavirus. Most of the children who acquired rotavirus infection nosocomially showed symptoms of diarrhea, vomiting, fever, poor sucking, or dehydration, regardless of the genotype. This study revealed that G4P[6] has been the major genotype causing nosocomial rotavirus infection in our hospital.
Rotavirus Infections/classification/*microbiology ; Rotavirus/*classification/*genetics ; Male ; Infant ; Humans ; Genotype ; Feces/microbiology ; Diarrhea/*microbiology ; Cross Infection/classification/*microbiology ; Child, Preschool

To characterize rotavirus G and P genotypes circulating among infants and young children hospitalized with severe diarrhea in a university hospital in Gyeonggi province, Korea, and to examine any association of the genotypes and nosocomial infections, we genotyped 103 isolates of rotavirus by multiplex RT-PCR. In July 2001-June 2002, we found that globally common strains constituted 64.2% (G2P[4] 28.3%, G3P[8] 28.3%, G4P[8] 5.7%, and G1P[8] 1.9%), and the uncommon strain, G4P[6], constituted 26.4%. During July 2002-June 2003, the percentage of common strains decreased to 44.0% (G3P[8] 18.0%, G2P[4] 16.8%, and G1P[8] 10.0%), but G4P[6] increased to 36.0%. G9P[8] was identified in 10.0% of cases, and thus can be considered an emerging strain in Korea. Eight-eight percent of G4P[6] was isolated from newborn babies. Among the 103 patients, there was an evidence of nosocomial rotavirus infection in 23 children (22.3%). Of these, 19 (82.6%) were newborns infected with G4P[6] strains of rotavirus. Most of the children who acquired rotavirus infection nosocomially showed symptoms of diarrhea, vomiting, fever, poor sucking, or dehydration, regardless of the genotype. This study revealed that G4P[6] has been the major genotype causing nosocomial rotavirus infection in our hospital.
Rotavirus Infections/classification/*microbiology ; Rotavirus/*classification/*genetics ; Male ; Infant ; Humans ; Genotype ; Feces/microbiology ; Diarrhea/*microbiology ; Cross Infection/classification/*microbiology ; Child, Preschool

OBJECTIVEIn order to find out a more convenient, rapid and efficient way in detecting human Norovirus infections in specimens collected from hospitalized patients with acute non-bacterial diarrhea in Beijing.

METHODSTwo kits for enzyme immunoassay (EIA) were used to detect human Noroviruses in stool specimens collected from 69 infants and young children as well as 15 adults who were all diagnosed as acute non-bacterial diarrhea in 4 different hospitals. Reverse transcription-polymerase chain reaction(RT-PCR) was performed to evaluate the data from two kits in this study. Data were statistically analyzed by SPSS 11.5 software. chi2 test was used to test categorical variables.

RESULTSOut of 84 stool specimens collected from infants and young children or adults with acute non-bacterial diarrhea, 17 (20.2%) were Norovirus positive determined by EIA kit A and 31 (36.9%) were Norovirus positive determined by EIA kit B. chi2 test used to test categorical variables showed significant differences (P < 0.01), suggesting that the EIA kit B was superior to the EIA kit A. Among these 84 stool specimens, 20 were tested by RT-PCR simultaneously. Out of those 20 specimens, 11 (55.0%) were Norovirus positive as determined by RT-PCR, which was higher than that from 2 EIA kits.

RESULTSfrom 10 (50.0%) samples detected by EIA kit A were consistent with those detected by RT-PCR. Through chi2 test, the categorical variables showed significant differences with P < 0.05, suggesting that RT-PCR was superior to the EIA kit A. Results from 14 (70.0%) samples detected by EIA kit B were consistent with those detected by RT-PCR while chi2 test showed that the differences were not significant (P > 0.05), among categorical variables suggesting that EIA kit B was as sensitive as RT-PCR in detecting Norovirus. The were hospital acquired diarrhea outbreaks in these three hospitals since at least 2 Norovirus positive specimens were detected in each of the hospitals.

CONCLUSIONTo detect human Noroviruses infection, EIA seemed to be more convenient and time saving than RT-PCR which had been used worldwide. The EIA kit B in this study was comparable to RT-PCR for detecting Norovirus in stool specimens. Norovirus was a pathogen causing hospital acquired diarrhea outbreaks in these three hospitals.

Adult ; Caliciviridae Infections ; diagnosis ; Child ; Child, Preschool ; China ; Cross Infection ; diagnosis ; Diarrhea ; virology ; Feces ; virology ; Hospitals ; Humans ; Immunoenzyme Techniques ; Infant ; Norovirus ; genetics ; Reverse Transcriptase Polymerase Chain Reaction