Analysis of the influencing factors of urinary tract infection in pregnant women with diabetes and the distribution characteristics of pathogens in the middle urinary tract / 中国医师杂志

Objective:To investigate the influencing factors of urinary tract infection in pregnant women with diabetes and the distribution characteristics of pathogens in the middle urinary tract.Methods:A total of 220 patients with gestational diabetes who visited the Second People′s Hospital of Lianyungang City from December 2018 to December 2021 were selected as the study subjects, and the incidence of urinary tract infection was counted. According to the diagnosis results of urinary tract infection, they were divided into infected group and uninfected group. The infected group took the middle urine for pathogen culture, and the resistance rate of main gram-negative bacteria to antibiotics was analyzed; Logistic regression model was used to analyze the influencing factors of urinary tract infection in pregnant women with diabetes.Results:There were 32 cases of urinary tract infection in 220 patients with gestational diabetes, and the infection rate was 14.55%(32/220). 43 strains of pathogenic bacteria were identified, mainly gram-negative bacilli [72.09%(31/43)], followed by gram-positive cocci [20.93%(9/43)] and fungi [6.98%(3/43)]. Amongthe main gram-negative bacteria, escherichia coli had a high resistance rate to ampicillin and levofloxacin, while Klebsiella pneumoniae had a high resistance rate to ampicillin and cefazolin; There were significant differences between the infected group and the non infected group in age, hospital stay, personal urinary tract infection history, pregnancy sexual life history, use of antibiotics, fasting blood sugar, serum albumin, and glycated hemoglobin (all P<0.05); Multivariate logistic regression results showed that personal history of urinary tract infection, sexual life during pregnancy, non-standard use of antibiotics, serum albumin<30 g/L, glycated hemoglobin ≥7%, and fasting blood sugar ≥8.5 mmol/L were independent risk factors for urinary tract infection in pregnant diabetes patients (all P<0.05). Conclusions:There is a high incidence of urinary tract infection in patients with gestational diabetes, and the risk factors are complex. Gram negative bacilli are the main pathogenic bacteria. Antibacterial drugs can be reasonably selected for intervention according to drug sensitivity test in clinical practice.

Advances in automated techniques to identify Acinetobacter calcoaceticus-Acinetobacter baumannii complex.

Acinetobacter species, particularly those within Acinetobacter calcoaceticus-A. baumannii complex (ACB complex), have emerged as clinically relevant pathogens in hospital environments worldwide. Early and quick detection and identification of Acinetobacter infections is challenging, and traditional culture and biochemical methods may not achieve adequate levels of speciation. Moreover, currently available techniques to identify and differentiate closely related Acinetobacter species are insufficient. The objective of this review is to recapitulate the current evolution in phenotypic and automated techniques used to identify the ACB complex. Compared with other automated or semiautomated systems of bacterial identification, matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) demonstrates a high level of Acinetobacter species identification and discrimination, including newly discovered species A. seifertii and A. dijkshoorniae.

The technical development and application prospects of CRISPR/Cas9 in laboratory medicine / 中华检验医学杂志

Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRISPR/Cas9),a cluster of regularly spaced short palindromic repeats,is a natural immune defense system for bacteria and archaea to identify themselves and exogenous invading DNA fragments,protecting them from viruses.In recent years,CRISPR/Cas9 has become a revolutionary gene editing tool.Its specific targeted spot-cutting ability also plays an important role in nucleic acid detection,bacterial typing,etc.,and has shown great application potential in the field of medical testing.Based on the latest researches,this paper reviews the progress of CRISPR/Cas9 application in the new techniques of nucleic acid detection,pathogen typing and bacterial evolution in laboratory medicine,and also summarizes the application prospect of CRISPR technology in the field of laboratory medicine.

Molecular typing of Brucella abortus strains in Xinjiang / 中华地方病学杂志

Objective To identify molecular typing of Brucella abortus isolates in Xinjiang,and determine the identification ability of multiple locus variable-number tandem repeat analysis (MLVA).Methods The optimized Brucella AMOS-PCR was used for identification of Brucella (n =7) genus and species in Xinjiang from 2010-2015,and MLVA-16 was used to further identify the isolates.Results were compared with the data of the Brucella standard strain provided by the http://mlva.u-psud.fr database.Cluster analysis was carried out with Bionumerics 6.6.Results The results of AMOS-PCR and MLVA-16 were identical,all were Brucella abortus.Further classification results of the MLVA-16 showed that the strain in Xinjiang was type 3 of Brucella abortus,which was basically the same as that of the domestic Brucella.Conclusions The molecular typing of isolates separated in Xinjiang is type 3 of Brucella abortus.MLVA can identify Brucella at the level of species,and highly sensitive to Brucella biotype and isolates differences,which provides a basis for the traceability and evolution of brucellosis epidemic strains.

Detección de cassette cromosómico en cepas de Staphylococcus aureus resistente a meticilina aisladas en un hospital universitario de la ciudad de Maracaibo / Detection of chromosomal cassette in MRSA Staphylococcus aureus strains isolated in a University Hospital in Maracaibo City

Staphylococcus aureus resistente a meticilina, es un importante patógeno nosocomial y comunitario. El determinante genético de resistencia es el gen mecA. Se han descrito 11 tipos de SCCmec, encontrándose con frecuencia los tipos II, III en infecciones hospitalarias, y los tipos IV y V en infecciones comunitarias. La presente investigación se llevó a cabo para estudiar la distribución de los tipos de SCCmec y su relación con la Leucocidina Panton-Valentine, tipificados mediante la reacción en Cadena de la Polimerasa. Para ello se estudiaron un total de 42 cepas resistentes a meticilina portadoras del gen mecA. Veintinueve (29) cepas mostraron la presencia del cassette cromosomal tipo IV (69,05%); 30,95% presentaron el SCCmec tipo I. Un 61,95% (n=13) de las cepas fueron portadoras del SCCmec IV resultando todas positivas para el gen PVL. Cabe destacar la diseminación del cassette tipo IV en cepas intrahospitalarias portadoras de PVL, lo que es preocupante tanto para la terapéutica como para el agravamiento de las infecciones en los pacientes.

Methicillin-resistant Staphylococcus aureus is an important nosocomial and community pathogen. The genetic determinant of resistance is the mecA gene. 11 types of SCCmec have been described, with types II, III frequently found in hospital infections, and types IV and V in community infections. The present investigation was carried out to study the distribution of the SCCmec types and their relation with the Panton-Valentine Leucocidin, typified by the reaction in the Polymerase Chain. To this end, a total of 42 methicillin-resistant strains carrying the mecA gene were studied. Twenty-nine (29) strains showed the presence of type IV chromosomal cassette (69.05%); 30.95% presented SCCmec type I. A 61.95% (n= 13) of the strains were carriers of SCCmec IV, all of which were positive for the PVL gene. It is worth noting the dissemination of the type IV cassette in intrahospital strains carrying PVL, which is worrisome both for the therapeutic and for the aggravation of infections in patients.

Application of OrthoANI combined with MALDI-TOF MS in identification and typing of Campylobacter fetus / 中华检验医学杂志

Objective@#Establishing the mass spectrum library of a new Campylobacter- " C.fetus subsp.testudinum" for rapid species identification in clinical microbiology laboratory.@*Methods@#Illumina second generation sequencing platform 2000/miSeq was used to carry out high flux genome sequencing for the strains which were collected to establish mass spectrum library.The analysis oforthologous average nucleotide identity (OrthoANI) between collected strains and reference strains was performed at JAVA 8 operation environment. Then, the mass spectrums ofcollected strains andreference strains were acquired using MALDI-TOF MS. And the mass spectrum library of C. fetus subsp.testudinum. were established and verified.@*Results@#The OrthoANI analysis showed that the OrthoANI value of the collected strains and the reference strain C. fetus subsp.testudinum03-427 was 99.30%-99.96%, while the OrthoANI values of collected strains and C. fetus subsp.venerealisNCTC10354 orC.fetus subsp.fetus82-40 were 91.05%-92.26%. With reference to OrthoANI ≥ 95% as the basis for the determination of the same strain, the strains which collected to establish mass spectrum library was finally identified as " C. fetus subsp.testudinum" . The identification accuracy rate of the mass spectrum library was 100% (consistent with gene sequencing), and the confidence interval was 82.3%-99.9%, identification of the same strain is 100% reproducible.@*Conclusions@#The new" gold standard" based on high throughput sequencing and total genome analysis has provided the ideal reference value for the establishment of mass spectrum library.And the accurate and objective reference spectrum of the" C.fetus subsp.testudinum" provides a new platform for the rapid diagnosis of fetal Campylobacter infection. (Chin J Lab Med, 2018, 41: 583-588)

Inhibición del crecimiento de Erwinia chrysanthemi a diferentes concentraciones de ácido fólico: posible uso del ácido fólico como agente bacteriostático y fortificante de la papa Solanum tuberosum / Inhibition of Erwinia chrysanthemi growth to different concentrations of folic acid: possible use of folic acid as bacteriostatic agent and fortifying of Solanum tuberosum potato

Resumen Introducción: Las enterobacterias del genero Erwinia spp producen enfermedades en la papa, un tubérculo de consumo masivo. La regulación de la metilación del DNA puede regular la proliferación de la Erwinia, de tal modo que las concentraciones del ácido fólico, pueden tener un efecto en la capacidad patógena del microorganismo. De otra parte, el ácido fólico previene la aparición de defectos del tubo neural en humanos. Objetivo: Evaluar al ácido fólico como un agente bacteriostático de la Erwinia y que a su vez sea parte de la fortificación de alimentos de consumo masivo como la papa. Materiales y métodos: Se llevó a cabo la caracterización bioquímica de la Erwinia chrysanthemi, se estudió su crecimiento frente a diferentes concentraciones de ácido fólico Resultados: Al aumentar las concentraciones de la vitamina, desde 0,3 µg/L hasta 6,8 µg/L se inhibe el crecimiento bacteriano de la Erwinia chrysanthemi. La vitamina inhibe el crecimiento en cultivo de Erwinia chrysanthemi y actúa como como agente bacteriostático, aspecto es de gran relevancia dado que teóricamente, si la papa estuviera fortificada con el micronutriente, este actuaría contra el agente infeccioso y al mismo tiempo contribuiría al consumo adecuado de la vitamina en la población general.

Abstract Introduction: The enterobacteria of the Erwinia spp genus produce disease in potatoes, which is a tuber of mass consumption. The regulation of DNA methylation can regulate the proliferation of Erwinia in such a way that the concentrations of folic acid may have an effect on the microorganism pathogenic ability. On the other hand, the folic acid prevents the appearance of neural tube defects in humans. Objective: To evaluate folic acid as a bacteriostatic agent of Erwinia and, at the same time, as part of the fortification of mass consumption food such as the potatoes. Materials and methods: The biochemical characterization of the Erwinia chrysanthemi was carried out and its growth compared to different concentrations of folic acid was studied. Results: When increasing the concentrations of the vitamin from 0.3 µg/L up to 6.8 µg/L, the bacterial growth of Erwinia chrysanthemi is inhibited. The vitamin inhibits the growth in cultivation of Erwinia chrysanthemi and acts as a bacteriostatic agent. This aspect is of great importance given that, theoretically, if potatoes were fortified with micro-nutrient, this would act against the infectious agent and, at the same time, contribute to the adequate intake of the vitamin in the general population.

Estandarización del análisis multi-locus de número variable de repeticiones en tándem para el estudio de staphylococcus aureus resistentes a meticilina aislados de la comunidad en Paraguay / Multiple-locus variable-number of tandem repeat analysis standardization for community isolates methicilineresistant staphylococcus aureus study in Paraguay

Staphylococcus aureus es un patógeno capaz de causar infecciones con amplio rango de severidad y adaptarse a diferentes tejidos. Su epidemiología es compleja, por circulación de cientos de clones a nivel mundial, lo que requiere de métodos moleculares reproducibles y de alto poder discriminatorio para la identificación de los mismos. El presente estudio tuvo como objetivo principal la estandarización del análisis multi-locus de número variable de repeticiones en tándem (MLVA) para análisis de variabilidad genética de aislados de S. aureus previamente tipificados por electroforesis en gel de campo pulsado (PFGE), gold standard para tipificación de aislados. La MLVA se realizó por amplificación de 7 locus VNTR (clfA, clfB, sdrC, sdrD, sdrE, sspA y spA) por PCR. Se alcanzó un alto nivel de reproducibilidad. El empleo de cepas previamente tipificadas por análisis de secuencias multi-locus (MLST), PFGE, locus spa y cassette SCCmec, permitió validar de forma comparativa el agrupamiento generado por MLVA. Los aislados que fueron agrupados como idénticos por MLVA presentaron resultados congruentes con la totalidad de las otras técnicas moleculares y esta demostró ser más sensible que PFGE para distinguir entre aislados que presentaron patrones PFGE idénticos. La MLVA cumple todos los criterios de un método de tipificación útil.

Staphylococcus aureus is a pathogen that can produce several infections with a wide range of severity and it has the ability to adapt to different tissues. The epidemiology is complex, due to circulation of many different clones worldwide, so the analysis for its identification requires reproducible and high discriminatory power molecular methods. The aim of this study was to standardize the molecular technique multiple-locus variable number of tandem repeat analysis (MLVA) for the genetic variability analysis of S. aureus isolates, previously characterized by pulsed field gel electrophoresis (PFGE). The MLVA was made by PCR amplification of seven VNTR locus (clfA, clfB, sdrC, sdrD, sdrE, sspA y spA). A high level of reproducibility has been reached in the study. The use of isolates previously typified by multi-locus sequence typing (MLST), PFGE, locus spa and cassette SCCmec, allowed to validate the MLVA clusters comparatively. The isolates that were clustered by MLVA as the same isolate, showed the same results by other molecular techniques, and the MLVA can distinguish isolates with identical PFGE patterns. This technique meets all the criteria of a useful molecular typification technique.

Application of MALDI-TOF mass spectrometry in bacterial typing / 中华检验医学杂志

As a rapid, accurate and high throughput bacterial identification technique, matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF MS)has been gradually applied to clinical microbiological laboratories.However, the application of MALDI-TOF MS is far beyond the identification of bacteria.It also has broad application prospect in bacterial typing.The MALDI-TOF MS based typing method is simple, rapid, low-cost and high throughput, which can play an important role in nosocomial infections surveillance.

Identifation methods of Brucella Melitensis / 中华地方病学杂志

Objective To establish genotyping methods for rapid identification of Brucella melitensis (B.melitensis) biovar 1,2 and 3 and to verify these method.Methods Single nucleotide polymorphism of RpoB gene and tandem repeat sequence (TRS) Bru42 of standard reference strain 16M were used to design primers,then the RpoB-PCR and TRS-PCR method were established for identification of B.melitensis standard reference strains,these two methods were used to identify clinical isolates of B.melitensis and compared with the conventional methods.Results The results of B.melitensis standard reference strains (biotype 1,2,3) identified by RpoB-PCR and TRS-PCR were consistent with those of the conventional identification methods.Totally 50 clinical isolates [including B.melitensis biovar 1 (17),2 (3) and 3 (30)] were identified as RpoB-2 genotype,only one B.melitensis biovar 1 strain was identified as RpoB-3 genotype.Genotype identification results of standard reference strains and clinical isolates with the same biotype were not exactly the same.Fothermore,TRS-PCR experiment displayed that 51 clinical isolates were all genotype 2 of B.melitensis (genotype TRS-2).Conclusions There is no clear relationship between biovars and genotypes within B.melitensis,and significant difference exists between B.melitensis standard reference strains and clinical isolates within RpoB gene.Bru42 can not be used for genotyping clinical isolates of B.melitensis.

Identifation methods of Brucella Melitensis / 中华地方病学杂志

Objective To establish genotyping methods for rapid identification of Brucella melitensis (B.melitensis) biovar 1,2 and 3 and to verify these method.Methods Single nucleotide polymorphism of RpoB gene and tandem repeat sequence (TRS) Bru42 of standard reference strain 16M were used to design primers,then the RpoB-PCR and TRS-PCR method were established for identification of B.melitensis standard reference strains,these two methods were used to identify clinical isolates of B.melitensis and compared with the conventional methods.Results The results of B.melitensis standard reference strains (biotype 1,2,3) identified by RpoB-PCR and TRS-PCR were consistent with those of the conventional identification methods.Totally 50 clinical isolates [including B.melitensis biovar 1 (17),2 (3) and 3 (30)] were identified as RpoB-2 genotype,only one B.melitensis biovar 1 strain was identified as RpoB-3 genotype.Genotype identification results of standard reference strains and clinical isolates with the same biotype were not exactly the same.Fothermore,TRS-PCR experiment displayed that 51 clinical isolates were all genotype 2 of B.melitensis (genotype TRS-2).Conclusions There is no clear relationship between biovars and genotypes within B.melitensis,and significant difference exists between B.melitensis standard reference strains and clinical isolates within RpoB gene.Bru42 can not be used for genotyping clinical isolates of B.melitensis.

SDS-PAGE Analysis of the Outer Membrane Proteins of Uropathogenic Escherichia coli Isolated from Patients in Different Wards of Nemazee Hospital, Shiraz, Iran.

BACKGROUND: Outer membrane proteins (OMPs) constitute the main structure and about half of the cell wall of Gram-negative bacteria. The OMPs of Escherichia coli (E. coli) play an important role in its drug resistance. Previous studies have shown that the OMPs of E. coli enhance its pathogenic effects by helping the bacterium to evade the immune defense and promote its adsorption to host cells. We sought to compare E. coli isolates collected from different hospital wards and to perform a primary investigation of the association between the serotypes and profiles of their OMPs. We also aimed to detect the diversity of the E. coli isolates from the hospitalized patients. METHODS: A total of 115 isolates of E. coli were collected from patients hospitalized in Nemazee Hospital, Shiraz, Iran. After biochemical and serological tests, OMPs were extracted by using glass beads and N-Lauroylsarcosine sodium. OMP typing was done by 10% SDS-PAGE and Coomassie brilliant blue staining. In terms of the number of protein bands, OMP-I was detected with 2 bands, OMP-α with 3 bands, and OMP-ß with1 band. RESULTS: Of the 115 isolates, 103 were OMP-I and 12 were OMP-α; none of the isolates belonged to OMP-ß. Our statistical analyses showed a relationship between OMP patterns and other factors, including hospital wards and source of samples. Serotyping showed that the majority of the isolates were O128. CONCLUSION: Our results demonstrated some similarities between the OMP band patterns of the analyzed groups of E. coli. Of all the OMPs in the isolates from the hospitalized and outpatient department patients, OmpA and OmpC were the most prevalent proteins in the outer membrane of the studied uropathogenic E. coli.

Salmonella in the tropical household environment--Everyday, everywhere.

OBJECTIVES: To determine the prevalence of Salmonella in the environment of case and control houses, and compare serovars isolated from cases and their houses. METHODS: From 2005 to 2008, we tested samples from houses of 0-4 year old cases and community controls in Darwin and Palmerston for Salmonella. Case isolates were compared with environmental isolates. S. Ball and S. Urbana isolates were compared using Multiple Amplification of Phage Locus Typing (MAPLT) and Multiple-Locus Variable number of tandem repeat Analysis (MLVA). RESULTS: Salmonella were found in 47/65 (72%) case houses and 18/29 (62%) control houses; these proportions were not significantly different. In 21/47 (45%) houses, case and environmental isolates (from animal faeces, soil and vacuums) were indistinguishable. Multiple serovars were isolated from 20 (31%) case and 6 (21%) control houses. All but one environmental isolate are known human pathogens in the Northern Territory (NT). Each of the four pairs of S. Ball and S. Urbana were indistinguishable. CONCLUSIONS: Animal faeces were the most likely source of salmonellosis in cases. The similar prevalence of house isolates suggests that Salmonella is ubiquitous in this environment. The distinction of S. Ball and S. Urbana subtypes enabled linkage of human illness to environmental exposure. Environmental contamination with Salmonella is an important source of sporadic infection in children in the tropics.

Evaluation of MALDI Biotyper and VITEK MS for identifying clinical isolated Streptococcus spp / 中华检验医学杂志

Objective Using 16S rRNA gene sequencing as the gold standard method,to compare the performance of two matrix-assisted laser desorption ionization time of flight mass spectrometry system (MALDI Biotyper and VITEK MS) for identifying clinical isolates of Streptococcus spp.Methods One hundred and sixty two clinical Streptococcus isolates were collected at the Second Affiliated Hospital of Zhejiang University,from April to June,2014,and confirmed by 16S rRNA gene sequencing analysis.MALDI Biotyper and VITEK MS mass spectrometry system were used for identification and further evaluated by performance respectively.Results Of all the isolates tested,155 (155/162,95.68％) Streptococcus isolates were accurately identified to species level by MALDI Biotyper.Besides,MALDI Biotyper identified three Streptococcus mitis group as S.pneumoniae and one S.parasanguinis as S.australis.Another three S.pneumonia isolates were not identified accurately (values ＜ 1.7).Although 156 (156/162,96.30％) isolates were accurately identified to species level (including subspecies) by VITEK MS system,two S.pneumoniae as S.mitis/S.oralis and one S.euinus as S.infantarius ssp.infantarius were misidentified.The two systems showed a 100％ (51/51) accuracy in identifying all S.pyogenes and S.agalactiae isolates,and an accuracy higher than 85％ for S.pneumoniae.Conclusions Both systems showed potent identification ability for Streptococcus spp.,VITEK MS system showed more clinical significance in accurately identifying some subspecies.Mass spectrometry system can be used as a rapid identification method for Streptococcs spp.in clinical practice.

Infective endocarditis caused by Neisseria elongata on a native tricuspid valve and confirmed by DNA sequencing.

Neisseria elongata, a common oral bacterium, has been recognized as a cause of infections such as infective endocarditis, septicemia, and osteomyelitis. Neisseria-induced infective endocarditis, although infrequently reported, typically arises after dental procedures. Without antibiotic therapy, its complications can be severe. We report the case of a 27-year-old man who presented with fever, severe dyspnea, and a leg abscess from cellulitis. An echocardiogram showed a vegetation-like echogenic structure on the septal leaflet of the patient's native tricuspid valve, and an insignificant Gerbode defect. Three blood cultures grew gram-negative, antibiotic-susceptible coccobacilli that were confirmed to be N. elongata. Subsequent DNA sequencing conclusively isolated N. elongata subsp nitroreducens as the organism responsible for the infective endocarditis. The patient recovered after 21 days of antibiotic therapy. In addition to the patient's unusual case, we discuss the nature and isolation of N. elongata and its subspecies.

The retrospective study of oxacillin susceptible, mecA positive Staphylococcus aureus in China / 中华检验医学杂志

Objective The purpose of the study is to understand the epidemiology,distribution and molecular characteristics of oxacillin susceptible mecA positive Staphylococcus aureus (S.aureus).Methods Totally 1588 S.aureus isolates collected from 12 hospitals in 10 cities of China between 2010 and 2012 were retrospectively characterized.The isolates were characterized by antimicrobial susceptibility test of 20antimicrobial drugs.Three different methods (cefoxitin disc diffusion,agar dilution for oxacillin and cefoxitin) to detect oxacillin susceptible and mecA positive S.aureus were also compared.All the strains were confirmed to be S.aureus by detecting S.aureus specific genes by PCR (including nuc,femB,and mecA gene),which was viewed as the golden standard of MRSA.The molecular typing methods included SCCmec and spa typing.The statistical analyses were carried out in statistical product and service solutions (SPSS),Version 18.0.The significance level P was set at 0.05.Results According to the MICs of cefoxitin and oxacillin,a total of 60 isolates were oxacillin susceptible methicilin resistance Staphylococcus aureus (MRSA).Based on the differences of the specimen collection date,it is found that oxacillin susceptible MRSA have increased from 2010 to 2012 (P =0.05,95％ CI 0.045-0.056,X2 =6.099).These isolates were distributed in 9 major cities,and the highest prevalence is 30.0％ (18/60) in Guangzhou,followed by Beijing (18.3％,11/60),Wuhan (15.0％,9/60),Hangzhou (13.3％,8/60).Most of the isolates were from skin soft tissue infection (35％,21/60),blood stream infection (30％,18/60) and respiratory infection specimens (18.3％,11/60).The resistance rate to cefoxitin,erythromycin,clindamycin and tetracycline was 100％ (60/60),86.7％ (52/60),66.7％ (40/60) and 50％ (30/60),respectively.The molecular characterization showed that 21 spa and 5 SCCmec types were detected.The most predominant clone was spa t437-SCCmec Ⅳ (25.0％,15/60),followed by spa t437-SCCmecV (13.3％,8/60).Conclusions The detection rate of oxacillin susceptible MRSA is significantly higher from 2010 to 2012.The major clone is t437-SCCmec Ⅳ.The use of cefoxitin should replace oxacillin in detecting this type of MRSA.Further study is needed to confirm whether beta lactam antimicrobial agents should be used in the treatment of oxacillin susceptible mecA positive S.aureus.

Bacterial strain typing.

Over the course of the past several decades, rapid advancements in molecular technologies have revolutionized the practice of public health microbiology, and have fundamentally changed the nature, accuracy, and timeliness of laboratory data for outbreak investigation and response. Whole-genome sequencing, in particular, is becoming an increasingly feasible and cost-effective approach for near real-time high-resolution strain typing, genomic characterization, and comparative analyses. This review discusses the current state of the art in bacterial strain typing for outbreak investigation and infectious disease surveillance, and the impact of emerging genomic technologies on the field of public health microbiology.

The Application of DiversiLab System in Klebsiella pneumoniae Genotyping / 天津医药

Objective To analyze Klebsiella pneumoniae by DiversiLab system, providing scientific evidence for the control of nosocomial infection. Methods Eight strains of non-duplicated clinical Klebsiella pneumoniae isolated from the surgical ward in a hospital in 2010 were typed by rep-PCR-based DiversiLab system. The results were compared with those of pulsed-field gel electrophoresis (PFGE). Results Antimicrobial susceptibility test showed that 7 clinical strains were the same sensitivity to 11 antimicrobial agents, except the strain K8-02. And these 7 clinical strains were all multi-drug re-sistant. The result of PFGE showed that 7 strains were the same pattern. The result of DiversiLab also showed that 7 strains were the same pattern, and the strain K8-02 was another pattern. Conclusion DiversiLab system is simple, quick, good re-peatability and accurate, which is a kind of standardization and automation system. DiversiLab system and PFGE method could get the same result.

Rapid molecular assay and strain typing methods of extrapulmonary tuberculosis / 中华检验医学杂志

[Abstract] Objective To evaluate the effect of Mycobacterium tuberculosis Direct Assay (MTD) for rapid detecting Mycobacterium tuberculosis rRNA and Multi-locus PCR for M.bovis BCG strain typing in patients with suspected extra-pulmonary tuberculosis.Methods From June 2010 to December 2011,47 children and 75 adult patients with suspected extra-pulmonary tuberculosis in Shanghai public health clinical center were recruited.Also 48 non-tuberculosis patients were taken as a negative control.Clinical specimens from these patients were collected.Acid fast stain,solid culture,liquid culture,and MTD were used to detect all clinical specimens simultaneously.Screen tuberculosis strains of the culture isolates by MPT64 antigen assay and use Multi-locus PCR for the BCG strain genotyping of the isolates without MPT64 antigen.SPSS16.0 was used to analyse the results.Results The sensitivity for acid fast stain,solid culture,liquid culture and MTD test was 10.7％ (13/122),11.5％ (14/122),16.4％ (20/122) and 37.7％ (46/122),respectively.And the specificity of MTD was 100.0％.Six clinical isolates from children were identified as BCG by Multi-locus PCR typing,the same with chemical tests.Conclusions The MTD assay and the MGIT960 liquid culture are effective and reliable method for diagnosing extra-pulmonary tuberculosis.And Multi-locus PCR can be assisted for the early diagnosis of extra-pulmonary tuberculosis patients with suspected BCG infection.

Design of two molecular methodologies for the rapid identification of Colombian community-acquired methicillin-resistant Staphylococcus aureus isolates / Diseño de dos metodologías moleculares para la rápida identificación de aislamientos de Staphylococcus aureus resistente a meticilina asociados a la comunidad en Colombia

Introduction. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are found with increasing the frequency, both in healthy individuals in the community and in hospitalized patients. In Colombia and the Andean region, CA-MRSA isolates have a genetic background that is related to the pandemic USA300 clone. Objective. Two molecular methods are designed and standardized for the rapid differentiation of Colombian community-acquired and hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) isolates. Materials and methods. Two molecular methods were standardized for the identification of CA-MRSA isolates. The first method was based on the differential digestion of the carbamate kinase (arcC)and guanylate kinase (gmk) genes in the sequences type 5 (ST5) in the HA-MRSA isolates and 8 (ST8) in the CA-MRSA isolates. The second method was based on the PCR amplification of 5 specific virulence factors found in CA-MRSA and HA-MRSA isolates. The specificity and precision of each method were evaluated using 237 clinical MRSA isolates. Results. The first method identified 100% and 93.2% of the CA-MRSA and HA-MRSA isolates, respectively. The second method also correctly identified the two isolates types (CA-MRSA and HA-MRSA). Conclusions. These two methods are a convenient alternative for the rapid identification of the CA-MRSA isolates, compared with other techniques such as pulsed field gel electrophoresis and multilocus sequence typing, which are time-consuming and more expensive.

Introducción. Los aislamientos de Staphylococcus aureus resistente a la meticilina asociado a la comunidad (SARM-AC), están aumentando la frecuencia de infecciones en personas sanas de la comunidad y en pacientes hospitalizados. En Colombia y en la región andina estos aislamientos tienen un componente genético relacionado con el clon pandémico USA300. Objetivo. Diseñar y estandarizar dos metodologías para la diferenciación rápida de aislamientos colombianos de S. aureus resistente a la meticilina asociado a la comunidad de los asociados al hospital (SARM-AH). Materiales y métodos. Se estandarizaron dos metodologías moleculares para la identificación de aislamientos de S. aureus resistente a la meticilina asociado a la comunidad. La primera se basa en la digestión diferencial con tres enzimas de restricción de los genes cinasa de carbamato (arcC)y cinasa de guanilato (gmk)para los tipos de secuencia 5 (ST5) y 8 (ST8), correspondientes a aislamientos de S. aureus resistente a la meticilina asociado al hospital y asociado a la comunidad, respectivamente. La segunda se basa en la amplificación por reacción en cadena de la polimerasa de cinco factores de virulencia que se encuentran de manera diferencial en estos aislamientos. Las dos metodologías fueron validadas en 237 aislamientos clínicos de S. aureus resistente a la meticilina. Resultados. Con la primera metodología se identificaron el 100 % y 93,2 % de los aislamientos de S. aureus resistente a la meticilina asociado a la comunidad y asociado al hospital, respectivamente. Con la segunda metodología se identificaron correctamente los dos tipos de aislamientos. Conclusiones. Estas dos metodologías son una buena alternativa en términos de ahorro en tiempo y dinero comparadas con otras técnicas, como la electroforesis en campo pulsado y la tipificación de secuencias multilocus para la rápida identificación de aislamientos de S. aureus resistente a la meticilina asociado a la comunidad en Colombia.