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Objective:To evaluate the rapid nucleic acid amplification detection of Mycoplasma pneumoniae (MP)-DNA and MP-RNA in the diagnosis of MP infection and therapeutic values in children. Methods:Patients who were diagnosed with pneumonia were enrolled from the Department of Respiration, Children′s Hospital of Capital Institute of Pediatrics from January 2018 to December 2018.Specimens were detected using the MP and Macrolide-Resistant isolates Diagnostic Kit (PCR Fluorescence Probing, Jiangsu Mole Bioscience Co., Ltd.) and MP Diagnostic Kit (Isothermal RNA amplification, Shanghai Rendu Biotechnology Co., Ltd.).Results:Among them, 42.1%(840 cases) of the 1 994 cases were positive for MP-DNA, and the macrolide associated gene mutations were detected in 96.0% (806/840 cases) of them, while 33.9% (551 cases) of 1 624 cases were positive for MP-RNA.Seven hundred and fifty-eight specimens were simultaneously detected by adopting MP-DNA and MP-RNA, and the positive rate was 43.1% (327/758 cases) and 36.7% (278/758 cases), accordingly, which were inconsistent (Kappa=0.604) in 613 (80.9%, 613/758 cases) cases, with significant differences ( χ2=6.60, P=0.01). Part of the specimens were rechecked with the interval of 7 days: MP-RNA was negative in 70.1% (47/67 cases) specimens and MP-DNA was negative in 36.1% (22/91 cases) specimens ( χ2=33.20, P<0.01). Conclusions:The positive detection rate of MP was at a high level in 2018, in Beijing, China.The results of MP-DNA and MP-RNA are consistant.But RNA detection can help to diagnose MP in the early stage, and monitor the survival of MP and its efficiency.
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Objective To study the risk factors of intestinal bacteria colonization and antibiotic resistance among newborns in neonatal intensive care unit (NICU).Method From May 2014 to May 2015,newborns admitted to NICU in our hospital were enrolled and their feces were prospectively collected and cultured from day 5 to day 7 after birth.VITEK-2 system was used to identify the bacteria and determine their antibiotic susceptibility.Newborns were assigned into 8 groups according to their gestational age,mode of delivery and use of antibiotics,and the colonization rates of Escherichia coli (E.coli),Enterococcus and Klebsiella pneumoniae were compared.Result A total of 572 feces of newborns were collected,328 strains of E.coli,243 strains of Enterococcus and 70 strains of Klebsiella pneumoniae were isolated.The multi-drug resistance rates of E.coli and Enterococcus were 68.3％ (136/199) and 76.1％ (185/243),respectively.The colonization rates of E.coli,Enterococcus and Klebsiella pneumoniae of the full-term delivery without antibiotics group (77 cases),full-term Cesarean section (C-section) without antibiotics group (30 cases),premature C-section without antibiotics group (28 cases),premature delivery without antibiotics group (16 cases),premature delivery with antibiotics group (53 cases),full-term delivery with antibiotics group (155 cases),full-term C-section with antibiotics group (99 cases),premature C-section with antibiotics group (114 cases) were different.The antibiotics groups showed significantly less E.coli colonization rates and higher Enterococcus colonization rates than the non-antibiotics groups of the same gestational age and delivery mode (P ＜ 0.05).The result between the full-term C-section newborns and naturally delivered newborns without antibiotics indicated the similar trend (P ＜ 0.05).The colonization rates of Klebsiella pneumoniae showed no significant differences among the groups (P ＞ 0.05).Conclusion The multi-drug resistance of E.coli and Enterococcus in neonatal intestinal colonization is common and worrisome.Bacterial colonization is affected by antibiotics and the mode of delivery and prudent use of antibiotics is advised.
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Objective To understand the antibiotic resistance of bacteria colonized in intestine of the neonates from neonatal intensive care unit (NICU) and provide evidence to guide clinical antibiotic treatment.Methods From May,2014 to May,2015,a total of 572 stool samples were collected from the neonates of NICU in our hospital.Escherichia coli and Enterococcus were detected with VITEK-2 system.Results A total of 328 strains of E.coli and 243 strains of Enterococcus were isolated respectively in this study.The 199 strains of E.coli selected for drug susceptibility test showed lower resistant rate to imipenem,ertapenem,amikacin,nitrofurantoin,ranging from 0.50％ to 3.52％ and showed higher resistant rate to ampicillin,tetracycline,trimethoprim/sulfamethoxazole and cefazolin,ranging from 54.27％ to 84.92％.No meropenem resistant strainsere were found.The percentage of ESBLs production strains was 45％.The multi drug resistance test showed that 34.6％ of the strains were resistant to four antibiotics.Three strains were resistant to seven antibiotics.The 243 strains of Enterococcus showed lower resistant rate to quinupristin/dalfopristin,nitrofurantoin,streptomycin,ranging from 0.41％ to 4.53％ and showed higher resistant rate to ampicillin,benzylpenicillin,ciprofloxacin,tetracycline,gentamicin and erythromycin,ranging from 70.78％ to 91.77％.No strains which were resistant to tigecycline,vancomycin,rina thiazole amine/ketone were found.The multi drug-resistance test showed that 86.5％ of the strains were resistant to five antibiotics.Conclusions According to the analysis of the 199 strains ofE.coli and 243 strains of Enterococcus isolated from the neonates,we found that the resistance of intestinal bacteria in the neonates was very serious,showing multi drug resistance.It is necessary to use antibiotics according to the drug susceptibility test results in clinical treatment.
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Objective To understand the antibiotic resistance of bacteria colonized in intestine of the neonates from neonatal intensive care unit (NICU) and provide evidence to guide clinical antibiotic treatment.Methods From May,2014 to May,2015,a total of 572 stool samples were collected from the neonates of NICU in our hospital.Escherichia coli and Enterococcus were detected with VITEK-2 system.Results A total of 328 strains of E.coli and 243 strains of Enterococcus were isolated respectively in this study.The 199 strains of E.coli selected for drug susceptibility test showed lower resistant rate to imipenem,ertapenem,amikacin,nitrofurantoin,ranging from 0.50％ to 3.52％ and showed higher resistant rate to ampicillin,tetracycline,trimethoprim/sulfamethoxazole and cefazolin,ranging from 54.27％ to 84.92％.No meropenem resistant strainsere were found.The percentage of ESBLs production strains was 45％.The multi drug resistance test showed that 34.6％ of the strains were resistant to four antibiotics.Three strains were resistant to seven antibiotics.The 243 strains of Enterococcus showed lower resistant rate to quinupristin/dalfopristin,nitrofurantoin,streptomycin,ranging from 0.41％ to 4.53％ and showed higher resistant rate to ampicillin,benzylpenicillin,ciprofloxacin,tetracycline,gentamicin and erythromycin,ranging from 70.78％ to 91.77％.No strains which were resistant to tigecycline,vancomycin,rina thiazole amine/ketone were found.The multi drug-resistance test showed that 86.5％ of the strains were resistant to five antibiotics.Conclusions According to the analysis of the 199 strains ofE.coli and 243 strains of Enterococcus isolated from the neonates,we found that the resistance of intestinal bacteria in the neonates was very serious,showing multi drug resistance.It is necessary to use antibiotics according to the drug susceptibility test results in clinical treatment.
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Objective To compare different methods on the identification of Cronobacter (C.) spp.species and to choose an optimum one.Methods Biochemical test,16S rRNA and fusA sequencing methods were carried out.Results When using the biochemical test,105 strains showed six different conditions but C.turicensis and C.universalis could not be effectively identified.Under the 16S rRNA sequencing analysis,all the strains were divided into 5 groups but C.sakazakii and C.malonaticus were tangled.Finally,all the strains were identified into 58 C.sakazakii,30 C.malonaticus,11 C.dublinensis,5 C.turicensis,1 C.muytjensii,under the fusA sequencing analysis.Conclusion Currently,fusA sequencing analysis seemed an effective method for identifying the species of Cronobacter.Since fusA sequencing analysis method was less intuitive,another method for rapid testing should be developed.
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Objective To compare different methods on the identification of Cronobacter (C.) spp.species and to choose an optimum one.Methods Biochemical test,16S rRNA and fusA sequencing methods were carried out.Results When using the biochemical test,105 strains showed six different conditions but C.turicensis and C.universalis could not be effectively identified.Under the 16S rRNA sequencing analysis,all the strains were divided into 5 groups but C.sakazakii and C.malonaticus were tangled.Finally,all the strains were identified into 58 C.sakazakii,30 C.malonaticus,11 C.dublinensis,5 C.turicensis,1 C.muytjensii,under the fusA sequencing analysis.Conclusion Currently,fusA sequencing analysis seemed an effective method for identifying the species of Cronobacter.Since fusA sequencing analysis method was less intuitive,another method for rapid testing should be developed.
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Objective To elucidate the difference between methicillin-resistant Staphylococcus aureus (MRSA)and methicillin-sensitive S.aureus (MSSA)in terms of genotypes and distribution of virulence genes with the clinical strains isolated from Hohhot,and explore the relationship between the changing resistance of S.aureus and the virulence transition.Methods Pulsed field gel electrophoresis (PFGE)and multi locus sequence typing (MLST)methods were employed to do molecular typing for 30 MRSA strains and 30 MSSA strains isolated from inpatients in Hohhot,Inner Mongolia.PCR method was used to profile the distribution of virulence genes among these strains.Results PFGE typing results showed that 60 S.aureus strains were classified into 19 major types.MSSA strains belonged to 16 types,mainly types I and H.MRSA strains mainly belonged to types of K and M.Among the 20 strains with different PFGE types,MRSA strains were mainly identified as ST-239 type.but the prevalence of sec ,seg ,sei,sem,sen,seo,fnbB ,ebpS and cap 5 was higher in MSSA strains than in MRSA strains (P<0.05).Conclusions The clinical strains of S .aureus isolated from Hohhot showed diverse genotyping features.ST-239 was the major PFGE type of MRSA strains.The prevalence of virulence genes was higher in MSSA strains than in MRSA strains. Characteristic cluster is found for specific virulence genes.The results also suggest that acquisition of specific antibiotic resistance may be associated with change of specific virulence feature in S.aureus.
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Staphylococcus aureus induces chronic infection in form of biofilm that exists in the host cells and arthroplastic prosthesis surface. In this study, the biofilm formation ability of S. aureus clinically isolated from bacteremia patients, biofilm processing and relationship of resistance to antibiotics, and difference of biofilm formation ability on different prosthetic material surfaces were studied. All of them formed biofilm and especially 6 strains of S. aureus had high ability of biofilm formation. In addition, it was found that some strains with higher biofilm formation ability make more higher polysaccharide layer production. When S. aureus ATCC 25923 forms biofilm, minimal bactericidal concentration (MBC) of biofilm bacteria is more increased than that of the planktonic state bacteria about one thousand folds. Especially, after 6 hours from starting on biofilm formation, the resistance to antibiotics was increased by more than 256 microgram/ml of MBC to every antibiotics and after 8 hours prominent increase (more than 4096 microgram/ml) was noted. Biofilm formation after bacterial adherence to plastic cover-slip was increased with time-dependent manner. Microcolonies were formed after 5 hours from a point that bacteria adhere to plastic cover-slip surface and after 6 hours biofilm was diffusely formed on entire surface, and then after 8 hours very thick biofilm was formed. Thicker biofilm was found on cobalt-chromium than titanium surface. These results suggest that titanium alloy materials are better than cobalt-chromium to minimize S. aureus biofilm formation on the arthroplastic material surface. Also, when microcolonies are formed after adherence of S. aureus to the arthroplastic material surface, resistance to antibiotics is starting.
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Humans , Alloys , Anti-Bacterial Agents , Bacteremia , Bacteria , Biofilms , Plankton , Plastics , Prostheses and Implants , Staphylococcus , Staphylococcus aureus , TitaniumABSTRACT
BACKGROUND: Enteropathgenic Escherichia coli (EPEC) commonly causes infantile diarrhea in the developing countries. This study aims to find out the phenotypic and genotypic characteristics of EPEC in children with diarrhea in Gwangju city. METHODS: We isolated 35 strains from the stool obtained from diarrheal patients and investigated the presence of various virulence genes, adherence patterns, hemolysis, and antibiotic resistance patterns. RESULTS: All isolates were negative for the EPEC adherence factor (EAF) plasmid, and 14 isolates were bfpA-positive by PCR. The eae, tir, espA, and espB genes were analyzed by multiplex PCR. When the results of the four multiplex PCRs were analysed, we observed that the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was highest. The incidence of enteroaggregative E. coli heat-stable enterotoxin (east) was 17.1%. Analysis of Hep-2 cell adherence showed three adherence patterns:the localized adherence pattern, the diffuse adherence pattern, the localized adherence-like pattern. In hemolysin assay, four isolates produced enterohemolysin. The resistance rate of isolates against tetracycline, streptomycin, ampicillin, and rifampin was 56%, 39%, 34%, and 34%, respectively. All isolates were susceptible to ciprofloxacin and colistin. CONCLUSION: In our study, the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was the highest. Analysis of Hep-2 cell adherence showed various adherence patterns. Seventy-five percent of isolates were resistant to at least one antibiotic and 28% were resistant to four or more antibiotics.
Subject(s)
Child , Humans , Infant , Ampicillin , Anti-Bacterial Agents , Ciprofloxacin , Colistin , Developing Countries , Diarrhea , Diarrhea, Infantile , Drug Resistance, Microbial , Enteropathogenic Escherichia coli , Enterotoxins , Escherichia coli , Hemolysis , Incidence , Multiplex Polymerase Chain Reaction , Plasmids , Polymerase Chain Reaction , Rifampin , Streptomycin , Tetracycline , VirulenceABSTRACT
BACKGROUND: Enteropathgenic Escherichia coli (EPEC) commonly causes infantile diarrhea in the developing countries. This study aims to find out the phenotypic and genotypic characteristics of EPEC in children with diarrhea in Gwangju city. METHODS: We isolated 35 strains from the stool obtained from diarrheal patients and investigated the presence of various virulence genes, adherence patterns, hemolysis, and antibiotic resistance patterns. RESULTS: All isolates were negative for the EPEC adherence factor (EAF) plasmid, and 14 isolates were bfpA-positive by PCR. The eae, tir, espA, and espB genes were analyzed by multiplex PCR. When the results of the four multiplex PCRs were analysed, we observed that the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was highest. The incidence of enteroaggregative E. coli heat-stable enterotoxin (east) was 17.1%. Analysis of Hep-2 cell adherence showed three adherence patterns:the localized adherence pattern, the diffuse adherence pattern, the localized adherence-like pattern. In hemolysin assay, four isolates produced enterohemolysin. The resistance rate of isolates against tetracycline, streptomycin, ampicillin, and rifampin was 56%, 39%, 34%, and 34%, respectively. All isolates were susceptible to ciprofloxacin and colistin. CONCLUSION: In our study, the rate of the presence of eaegamma-tiralpha-espAalpha-espBalpha was the highest. Analysis of Hep-2 cell adherence showed various adherence patterns. Seventy-five percent of isolates were resistant to at least one antibiotic and 28% were resistant to four or more antibiotics.