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1.
Biomédica (Bogotá) ; 41(supl.2): 165-179, oct. 2021. tab, graf
Article in Spanish | LILACS | ID: biblio-1355768

ABSTRACT

Resumen | Introducción. Listeria monocytogenes es un patógeno transmitido por alimentos que causa infecciones en humanos, entre ellas, meningitis, meningoencefalitis y septicemias, así como abortos. Con la tipificación serológica se han identificado 13 serotipos, siendo el 4b el causante de la mayoría de los brotes en el mundo. Objetivo. Determinar la frecuencia y la distribución de los serotipos y subtipos moleculares de L. monocytogenes aislados de alimentos en Colombia entre el 2010 y el 2018. Materiales y métodos. Se hizo un estudio descriptivo y retrospectivo a partir del análisis de 2.420 aislamientos que fueron identificados como L. monocytogenes y otras especies, por medio de pruebas bioquímicas, serológicas y de subtipificación molecular mediante electroforesis en gel de campo pulsado (PFGE). Resultados. De los 2.420 aislamientos recibidos, 2.326 fueron confirmados como L. monocytogenes. Los serotipos encontrados fueron: 4b (52%), 4d-4e (14,5%), 1/2a (11%), 1/2c (9,4%), 1/2b (9 %), y 3a, 3b, 3c, 4c, 4d, 4e y 7 (menos de 2%). Procedían de Bogotá (43%), Antioquia (25%), Valle (10%), Nariño (9%) y otros departamentos (7%). La caracterización genotípica agrupó los aislamientos evaluados en 167 patrones de PFGE; los perfiles más frecuentes se presentaron en productos lácteos, cárnicos y alimentos preparados. Conclusión. El 96,1 % de los aislamientos correspondieron a L. monocytogenes, con una buena concordancia entre el aislamiento y la identificación; el serotipo 4b, extremadamente virulento, fue el más frecuente. El análisis molecular evidenció la posible diseminación y permanencia en el tiempo de varios serotipos, lo que resalta la importancia de incluir este patógeno en los programas de vigilancia epidemiológica en alimentos.


Abstract | Introduction: Listeria monocytogenes is a food-borne pathogen that may cause infections in humans such as meningitis, meningoencephalitis, and septicemia, as well as abortions. By serological typing 13 serotypes have been identified of which 4b is responsible for most of the outbreaks in the world. Objective: To determine the frequency and distribution of serotypes and molecular subtypes of L. monocytogenes isolated in Colombia from food from 2010 to 2018. Materials and methods: We conducted a retrospective and descriptive study based on the analysis of 2,420 isolates confirmed as L. monocytogenes and other species using biochemical and serological tests, and pulsed-field gel electrophoresis (PFGE) for molecular subtyping. Results: Of the 2,420 isolates received, 2,326 were confirmed as L. monocytogenes. The serotypes found were 4b (52%), 4d-4e (14.5%), 1/2a (11%), 1/2c (9.4%), 1/2b (9%), and 3a, 3b, 3c, 4c, 4d, 4e and 7 (less than 2%). The isolates came from Bogotá (43%), Antioquia (25%), Valle (10%), Nariño (9%), and other departments (7%). The genotypic characterization grouped the isolates in 167 PFGE patterns. The most frequent patterns were identified in various dairy and meat products, and in prepared foods. Conclusion: A 96.1% of the isolates corresponded to L. monocytogenes showing good agreement between isolates and identification. Serotype 4b, highly virulent, was the most frequent. The molecular analysis showed the possible dissemination and permanence over time of several serotypes, which highlights the importance of including this pathogen in epidemiological food surveillance programs.


Subject(s)
Foodborne Diseases , Listeria monocytogenes , Electrophoresis, Gel, Pulsed-Field
2.
Biomédica (Bogotá) ; 41(2): 338-346, abr.-jun. 2021. tab, graf
Article in English | LILACS | ID: biblio-1339271

ABSTRACT

Abstract | Introduction: Streptococcus pneumoniae serotype 3 is an important cause of pneumonia, bacteremia, and meningitis. Objective: To establish the circulating genotypes of S. pneumoniae serotype 3 isolates recovered from the invasive disease between 1994 to 2015 in Colombia. Materials and methods: Of the 365 S. pneumoniae serotype 3 isolates recovered through the laboratory national surveillance program, 117 isolates were analyzed. Pulsed-field gel electrophoresis was used for genotyping, and multilocus sequence typing was determined in representative isolates. Results: The frequency of this serotype increased from 2.7% between 1994 and 1998 to 9.1% between 2011 and 2015 (p=0.000); 91.7% of the isolates showed a genetic similarity greater than 77% and were related to the Netherlands3-31(PMEN31) clone CC180. Several subtypes were identified, two of which showed antimicrobial resistance. Conclusion: In Colombia, the pneumococcal population of the capsular type 3 shows a continuous and homogeneous circulation relating to the clonal group ST-180.


Resumen | Introducción. El serotipo 3 de Streptococcus pneumoniae es una causa importante de neumonía, bacteriemia y meningitis. Objetivo. Establecer los genotipos circulantes de aislamientos del serotipo 3 de S. pneumoniae recuperados de muestras de enfermedad invasiva de 1994 a 2015 en Colombia. Materiales y métodos. Se analizaron 117 de los 365 aislamientos del serotipo 3 de S. pneumoniae recuperados del programa nacional de vigilancia por el laboratorio. El genotipo se estableció con electroforesis en gel de campo pulsado y la tipificación se llevó a cabo mediante secuenciación multilocus en aislamientos representativos. Resultados. La frecuencia de este serotipo aumentó de 2,7 % entre 1994 y 1998 a 9,1 % entre 2011 y 2015 (p=0,000). El 91,7 % de los aislamientos evidenció una similitud genética superior al 77 % y se relacionó con el clon CC180 de Netherlands3-31 (PMEN31). Se identificaron varios subtipos, dos de los cuales mostraron resistencia a los antimicrobianos. Conclusión. En Colombia, la población neumocócica del tipo capsular 3 tiene una circulación continua y homogénea relacionada con el grupo clonal ST-180.


Subject(s)
Streptococcus pneumoniae , Electrophoresis, Gel, Pulsed-Field , Colombia
3.
Rev. Soc. Bras. Med. Trop ; 54: e20200087, 2021. tab, graf
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP | ID: biblio-1136920

ABSTRACT

Abstract INTRODUCTION: In this study, we report a clonal dissemination of carbapenem resistant Acinetobacter baumannii isolates due to the acquisition of blaOXA-23 in a regional hospital located in Brazilian Amazon Region. METHODS: The isolates were identified by MALDI-TOF and the carbapenemase-encoding genes were detected by multiplex-PCR. The genetic similarity was investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: Only 10 (55.6%) isolates harbored the gene bla OXA-23. PFGE analysis revealed that these isolates belong to a single clone. CONCLUSIONS: This dissemination strategy indicates the need for surveillance, adoption of control procedures defined in guidelines, and the careful administration of antimicrobials should be reinforced.


Subject(s)
Humans , Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Bacterial Proteins/genetics , beta-Lactamases/genetics , Brazil/epidemiology , Drug Resistance , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Molecular Epidemiology , Hospitals , Anti-Bacterial Agents/pharmacology
4.
Chinese Medical Journal ; (24): 2573-2585, 2020.
Article in English | WPRIM | ID: wpr-877863

ABSTRACT

BACKGROUND@#Carbapenemase-producing Klebsiella pneumoniae (CP-Kp) poses distinct clinical challenges due to extensively drug resistant (XDR) phenotype, and sequence type (ST) 11 is the most dominant blaKPC-2-bearing CP-Kp clone in China. The purpose of this current retrospective study was to explore the genetic factors associated with the success of XDR CP-Kp ST11 strains circulated in the intensive care unit (ICU) of a Chinese tertiary hospital.@*METHODS@#Six ST11 XDR CP-Kp strains were identified between May and December 2014 and validated by minimum inhibitory concentration examination, polymerase chain reaction, and pyrosequencing. The six ST11 XDR CP-Kp, as well as three multi-drug resistant (MDR) and four susceptible strains, were sequenced using single-molecule real-time method. Comprehensively structural and functional analysis based on comparative genomics was performed to identify genomic characteristics of the XDR ST11 CP-Kp strains.@*RESULTS@#We found that ST11 XDR blaKPC-2-bearing CP-Kp strains isolated from inpatients spread in the ICU of the hospital. Functionally, genes associated with information storage and processing of the ST11 XDR CP-Kp strains were more abundant than those of MDR and susceptible strains, especially genes correlative with mobile genetic elements (MGEs) such as transposons and prophages. Structurally, eleven large-scale genetic regions taken for the unique genome in these ST11 XDR CP-Kp strains were identified as MGEs including transposons, integrons, prophages, genomic islands, and integrative and conjugative elements. Three of them were located on plasmids and eight on chromosomes; five of them were with antimicrobial resistance genes and eight with adaptation associated genes. Notably, a new blaKPC-2-bearing ΔΔTn1721-blaKPC-2 transposon, probably transposed and truncated from ΔTn1721-blaKPC-2 by IS903D and ISKpn8, was identified in all six ST11 XDR CP-Kp strains.@*CONCLUSION@#Our findings suggested that together with clonal spread, MGEs identified uniquely in the ST11 XDR CP-Kp strains might contribute to their formidable adaptability, which facilitated their widespread dissemination in hospital.


Subject(s)
Anti-Bacterial Agents , Bacterial Proteins , China , Electrophoresis, Gel, Pulsed-Field , Hospitals , Humans , Klebsiella Infections/drug therapy , Klebsiella pneumoniae/genetics , Microbial Sensitivity Tests , Multilocus Sequence Typing , Pharmaceutical Preparations , Retrospective Studies , beta-Lactamases/genetics
5.
Article in English | WPRIM | ID: wpr-762470

ABSTRACT

Active surveillance culture (ASC) can help detect hidden reservoirs, but the routine use of ASC for extended spectrum β-lactamase-producing Enterobacteriaceae is controversial in an endemic situation. We aimed to determine the prevalence and risk factors of extended spectrum β-lactamase-producing Klebsiella pneumoniae (EBSL-Kpn) colonization among intensive care unit (ICU)-admitted patients. Prospective screening of ESBL-Kpn colonization was performed for ICU-admitted patients within 48 hours for two months. A perirectal swab sample was inoculated on MacConkey agar supplemented with 2 µg/mL ceftazidime. ESBL genotype was determined by PCR-sequencing, and clonal relatedness was evaluated by pulsed-field gel electrophoresis (PFGE). The risk factors of ESBL-Kpn colonization were evaluated. The ESBL-Kpn colonization rate among the 281 patients at ICU admission was 6.4% (18/281), and bla(CTX-M-15) was detected in all isolates. ESBL producers also showed resistance to fluoroquinolone (38.9%, 7/18). All isolates had the same ESBL genotype (bla(CTX-M-15)) and a highly clustered PFGE pattern, suggesting cross-transmission without a documented outbreak. In univariate analysis, the risk factor for ESBL-Kpn colonization over the control was the length of hospital stay (odds ratio=1.062; P=0.019). Routine use of ASC could help control endemic ESBL–Kpn for ICU patients.


Subject(s)
Agar , Ceftazidime , Colon , Critical Care , Electrophoresis, Gel, Pulsed-Field , Enterobacteriaceae , Genotype , Humans , Intensive Care Units , Klebsiella pneumoniae , Klebsiella , Length of Stay , Mass Screening , Prevalence , Prospective Studies , Risk Factors
6.
Mem. Inst. Oswaldo Cruz ; 115: e200371, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135238

ABSTRACT

BACKGROUND Acinetobacter baumannii outbreaks have been associated with pandemic International Clones (ICs), but the virulence factors involved with their pathogenicity are sparsely understood. Pigment production has been linked with bacterial pathogenicity, however, this phenotype is rarely observed in A. baumannii. OBJECTIVES This study aimed to characterise the reddish-brown pigment produced by A. baumannii strains, and to determine its biosynthetic pathway by genomic approaches. METHODS Pigment characterisation and antimicrobial susceptibility were conducted by phenotypic tests. The clonal relationship was obtained by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The genome of an A. baumannii was obtained for characterisation of genes involved with pigment production. FINDINGS The pyomelanin was the pigment produced by A. baumannii. Strains were extensively drug resistant and belonged to the IC-5/ST79. The pyomelanin biosynthetic pathway was determined and presented a particular architecture concerning the peripheral (tyrB, phhB and hpd) and central (hmgB, hmgC and hmgR) metabolic pathway genes. The identification of a distant HmgA homologue, probably without dioxygenase activity, could explain pyomelanin production. Virulence determinants involved with adherence (csuA/BABCDE and a T5bSS-carrying genomic island), and iron uptake (basABCDEFGHIJ, bauABCDEF and barAB) were characterised. MAIN CONCLUSION There is a biosynthetic pathway compatible with the pyomelanin production observed in persistent A. baumannii IC-5 strains.


Subject(s)
Humans , Acinetobacter Infections/microbiology , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/genetics , Biosynthetic Pathways/genetics , Melanins , beta-Lactamases , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Acinetobacter baumannii/isolation & purification , Multilocus Sequence Typing , Pandemics , Anti-Bacterial Agents/pharmacology
7.
Rev. argent. microbiol ; 51(4): 354-358, dic. 2019. graf
Article in Spanish | LILACS | ID: biblio-1057400

ABSTRACT

Resumen El 27 de noviembre de 2008 ocurrió un brote de intoxicación alimentaria asociado al consumo de salpicón de ave en un jardín de infantes de Hurlingham, provincia de Buenos Aires. Treinta y siete niños y 10 adultos presentaron síntomas gastrointestinales. Cinco niños fueron internados con signos de deshidratación, y uno de ellos requirió cuidados intensivos. Se aisló Staphylococcus aureus subsp. aureus del alimento involucrado, de 4/5 muestras de materia fecal de pacientes y de 3/5 manipuladores (nariz del manipulador 1, manos de manipuladores 2 y 3). Las cepas aisladas portaban los genes que codifican las enterotoxinas SEA y SED. Por electroforesis de campo pulsado con la enzima SmaI, los patrones de macrorrestricción presentaron 100% de similitud. La investigación oportuna del brote permitió identificar al agente causal de la intoxicación, determinar las fallas en la elaboración del alimento e implementar las medidas correctivas correspondientes.


Abstract On November 27, 2008, a foodborne disease outbreak associated with the consumption of chicken salad occurred in a kindergarten in the District of Hurlingham, Province of Buenos Aires. Thirty-seven children and 10 adults with gastrointestinal symptoms were affected. Five children were hospitalized with signs of dehydration, one of them requiring intensive care. Staphylococcus aureus subsp. aureus was isolated from the mentioned food in 4 out of 5 stool specimens from the patients, and in 3 out of 5 food handlers (nose of food handler #1, hands of food handlers #2 and 3). The isolates carried the genes coding for enterotoxins SEA and SED. The macrorestriction patterns showed 100% similarity by pulsed-field gel electrophoresis using the SmaI enzyme. A timely outbreak investigation allowed us to identify the causative agent of the food poisoning as well as the failures in food processing and to implement corrective measures.


Subject(s)
Poisoning/etiology , Staphylococcus aureus/isolation & purification , Enterotoxins/analysis , Foodborne Diseases/diagnosis , Electrophoresis, Gel, Pulsed-Field/methods
8.
Rev. chil. infectol ; 36(5): 585-590, oct. 2019. graf
Article in Spanish | LILACS | ID: biblio-1058084

ABSTRACT

Resumen Introducción: Listeria monocytogenes es un patógeno transmitido por alimentos que causa listeriosis, una enfermedad que puede presentarse como gastroenteritis febril o en una forma invasora que tiene altas tasas de mortalidad. Hasta el momento, ha sido poco estudiada la diversidad genética de cepas de L. monocytogenes aisladas desde pacientes, alimentos y fuentes ambientales en Chile. Objetivo: Caracterizar genéticamente cepas de L. monocytogenes de estos tres orígenes recibidas por el Instituto de Salud Pública de Chile (ISP) entre los años 2007 y 2014. Material y Métodos: Se seleccionaron 94 cepas de L. monocytogenes correspondientes a 94 pulsotipos diferentes identificados por electroforesis en gel de campo pulsado (PFGE), se extrajo ADN y se realizó serotipificación mediante reacción de polimerasa en cadena (RPC) y tipificación de secuencias multilocus (MLST). Resultados: El serotipo más común fue 4b (55,3%), seguido de 1/2a (25,5%), 1/2b (17%) y 1/2c (2,2%). Se identificaron 32 secuencias tipo (ST), de las cuales cuatro fueron nuevas, y las predominantes fueron ST1 (28,7%) y ST2 (13,8%). La totalidad de las cepas se agrupó en los Linajes I y II. Conclusiones: Se observó una gran variabilidad genética en las cepas de L. monocytogenes analizadas, siendo predominantes las secuencias tipo ST1 y ST2, ambas pertenecientes al Linaje I. Nuestros resultados contribuyen a conocer la estructura poblacional de este patógeno en Chile y su presencia en muestras clínicas, alimentos y el medio ambiente.


Background: Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a disease that can present as febrile gastroenteritis or as an invasive form that has high mortality rates. So far, the genetic diversity of strains of L. monocytogenes isolated from patients, foods and environmental sources in Chile has been poorly studied. Aim: To characterize genetically L. monocytogenes strains received by the Institute of Public Health of Chile (ISP) between 2007 and 2014. Methods: We selected 94 strains of L. monocytogenes corresponding to 94 different pulsotypes identified by pulsed field gel electrophoresis (PFGE), DNA was extracted and serotyping was performed by polymerase chain reaction (PCR) and multilocus sequence typing (MLST). Results: The most common serotype was 4b (55.3%), followed by serotypes 1/2a (25.5%), 1/2b (17%) and 1/2c (2.2%). 32 sequence-type (ST) were identified, of which 4 were new, and the predominant ones were ST1 (28.7%) and ST2 (13.8%). All the strains of L. monocytogenes were grouped in Lineages I and II. Conclusions: A great genetic variability was observed in the strains of L. monocytogenes analyzed, being predominant the ST1 and ST2, both belonging to Lineage I. Our results contribute to know the population structure of this pathogen in Chile and its presence in clinical samples, food and the environment.


Subject(s)
Humans , Listeria monocytogenes/isolation & purification , Listeria monocytogenes/genetics , Time Factors , Genetic Variation , Serotyping , Chile , Polymerase Chain Reaction , Electrophoresis, Gel, Pulsed-Field , Environmental Microbiology , Multilocus Sequence Typing , Food Microbiology , Listeriosis/microbiology
9.
Braz. j. infect. dis ; 23(1): 8-14, Jan.-Feb. 2019. tab, graf
Article in English | LILACS | ID: biblio-1001504

ABSTRACT

ABSTRACT Introduction: Bacterial tonsillitis is an upper respiratory tract infection that occurs primarily in children and adolescents. Staphylococcus aureus is one of the most frequent pathogens in the etiology of tonsillitis and its relevance is due to its antimicrobial resistance and persistence in the internal tissues of the tonsils. Tonsillectomy is indicated in cases of recurrent tonsillitis after several failures of antibiotic therapy. Material and methods: In this study we evaluated 123 surgically removed tonsils from patients who had history of recurrent tonsillitis. The tonsils were submitted to microbiological analysis for detection of S. aureus. The isolates were identified by PCR for femA gene. Antimicrobial susceptibility of the isolates was determined by disk diffusion tests. All isolates were submitted to PCR to detect mecA and Panton-Valentine leucocidin (PVL) genes. The genetic similarity among all isolates was determined by pulsed field gel electrophoresis. Results: Sixty-one S. aureus isolates were obtained from 50 patients (40.7%) with mean age of 11.7 years. The isolates showed high level resistance to penicillin (83.6%), 9.8% had inducible MLSb phenotype, and 18.0% were considered multidrug resistant (MDR). mecA gene was detected in two isolates and the gene coding for PVL was identified in one isolate. The genetic similarity analysis showed high diversity among the isolates. More than one genetically different isolate was identified from the same patient, and identical isolates were obtained from different patients. Conclusions: MDR isolates colonizing tonsils even without infection, demonstrate persistence of the bacterium and possibility of antimicrobial resistance dissemination and recurrence of infection. A specific clone in patients colonized by S. aureus was not demonstrated.


Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Young Adult , Staphylococcal Infections/microbiology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/genetics , Tonsillitis/microbiology , Staphylococcus aureus/drug effects , Tonsillectomy/methods , Tonsillitis/surgery , Polymerase Chain Reaction , Cross-Sectional Studies , Electrophoresis, Gel, Pulsed-Field , Drug Resistance, Multiple, Bacterial/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/drug effects , Anti-Bacterial Agents/pharmacology
10.
Article in English | WPRIM | ID: wpr-739141

ABSTRACT

No study has described Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates that cause repetitive infections (recurrence and reinfection). We compared the microbiological characteristics of SDSE causing repetitive infections with those causing single infections. Three patients with invasive infections were identified based on their medical records, and multiple SDSE isolates were collected at intervals over three weeks, using a laboratory repository. Isolates from 12 patients with single-episode infections served as controls. Six isolates were collected from three patients with first and second episodes of infection. All isolates causing either repetitive or single-episode infection were subjected to emm typing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and random amplified polymorphic DNA (RAPD) analyses. Amplification of five virulence genes (sicG, prtF1, prtF2, lmb, and cbp), biofilm formation (BF), and cell invasion abilities (CIAs) were measured as virulent phenotypes. We observed close genetic similarities in the data obtained by emm typing, MLST, PFGE, and RAPD in four isolates from two patients, suggesting recurrence, whereas two isolates from one patient indicated genetic differences in these data, suggesting re-infection. The presence of the five virulence genes and the BF and CIA measurements appeared not to contribute to repetitive infections, compared with isolates causing single-episode infection. In conclusion, clinicians encountering patients with repetitive infections should be aware of both possibilities: recurrence with closely related strains and reinfection with different strains.


Subject(s)
Biofilms , DNA , Electrophoresis, Gel, Pulsed-Field , Humans , Medical Records , Multilocus Sequence Typing , Phenotype , Recurrence , Streptococcus , Virulence
11.
Article in English | WPRIM | ID: wpr-719650

ABSTRACT

BACKGROUND: Enterococcus faecalis strains with low-level resistance to linezolid (an oxazolidinone antibiotic) have become common. No large-scale study has examined the underlying mechanisms in linezolid-resistant E. faecalis (LRE) strains. We investigated these mechanisms and molecular characteristics in Chongqing, China. METHODS: A total of 1,120 non-duplicated E. faecalis strains collected from August 2014 to June 2017 underwent drug susceptibility testing. LRE strains were screened for optrA, cfr, and mutations in the 23S rRNA and ribosomal proteins L3 and L4 by PCR amplification and sequencing. Multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were used for epidemiological analysis. RESULTS: All 43 low-level LRE strains (minimum inhibitory concentration: 8–16 mg/L) harbored optrA; cfr and 23S rRNA mutations were not detected. Novel mutations in the ribosomal proteins L3 and L4—one deletion (Q103del) and four substitutions (S113L, T35A, I98V, and N79D)—were identified. Novel amino acid substitutions at positions E60K, G197D, and T285P of the OptrA protein were observed. MLST revealed 20 types of LRE strains; the most common type was ST16 (32.6%). PFGE showed 14 strains of ST16 with unique banding patterns. Eight novel sequence types (ST823 to ST830) and one allele (gki95) were identified for the first time in China. CONCLUSIONS: optrA plays an important role in linezolid resistance and may serve as a marker for resistance screening. Since the L3 and L4 mutations did not simultaneously occur in the same strain, they play a negligible role in linezolid resistance. Epidemiological investigation suggested that the LRE cases were sporadic.


Subject(s)
Alleles , Amino Acid Substitution , China , Electrophoresis, Gel, Pulsed-Field , Enterococcus faecalis , Enterococcus , Epidemiology , Linezolid , Mass Screening , Molecular Epidemiology , Polymerase Chain Reaction , Ribosomal Proteins
12.
Epidemiology and Health ; : e2019002-2019.
Article in English | WPRIM | ID: wpr-763760

ABSTRACT

OBJECTIVES: This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak. METHODS: This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested. RESULTS: Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same. CONCLUSIONS: The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.


Subject(s)
Abdominal Pain , Cacao , Case-Control Studies , Diarrhea , Eating , Electrophoresis, Gel, Pulsed-Field , Food, Preserved , Foodborne Diseases , Gastroenteritis , Humans , Korea , Meals , Odds Ratio , Salmonella enterica , Salmonella Infections , Salmonella , Sensation , Serogroup , Vomiting
13.
Article in Korean | WPRIM | ID: wpr-762283

ABSTRACT

BACKGROUND: Campylobacter jejuni is an important food-borne pathogen that causes human gastroenteritis. This study was conducted to investigate the incidence of isolation, antimicrobial susceptibility pattern, and C. jejuni genotype from diarrhea patients in Busan, Korea. METHODS: A total of 97 C. jejuni were isolated from diarrhea patients during five food-borne outbreaks from 2014 to September 2017. Antimicrobial susceptibility tests were carried out by the broth microdilution method for ciprofloxacin (CIP), nalidixic acid (NAL), tetracycline (TET), chloramphenicol, azithromycin (AZI), erythromycin (ERY), streptomycin (STR), gentamicin, and telithromycin. To investigate C. jejuni genotypes, pulsed-field gel electrophoresis (PFGE) profile analysis was performed. RESULTS: The isolation rate of C. jejuni was 2.0% for the last 4 years and increased annually. Antimicrobial resistance rates of C. jejuni were shown to be in the order of NAL (90.9%), CIP (89.4%), TET (13.6%), AZI (3.0%), ERY (3.0%), and STR (1.5%). The proportion of multidrug-resistance was 18.2%, and they commonly contained quinolones (CIP-NAL). Analysis of PFGE patterns of SmaI-restricted DNA of C. jejuni isolates showed 17 clusters; cluster 11 was the major genotype pattern. CONCLUSION: This study will provide useful data for the proper use of antimicrobials and the management of resistant C. jejuni. Also it will help to provide data for the epidemiological investigation of foodborne diseases caused by C. jejuni, which is expected to increase in the future.


Subject(s)
Azithromycin , Campylobacter jejuni , Campylobacter , Chloramphenicol , Ciprofloxacin , Diarrhea , Disease Outbreaks , DNA , Electrophoresis, Gel, Pulsed-Field , Erythromycin , Foodborne Diseases , Gastroenteritis , Genotype , Gentamicins , Humans , Incidence , Korea , Methods , Nalidixic Acid , Quinolones , Streptomycin , Tetracycline
14.
Epidemiology and Health ; : 2019002-2019.
Article in English | WPRIM | ID: wpr-785784

ABSTRACT

OBJECTIVES: This study aimed to reveal the epidemiologic characteristics of the outbreak of gastroenteritis caused by Salmonella enterica serovar Thompson in Busan Metropolitan City and to identify points for improvement to prevent of food-borne disease outbreak.METHODS: This was a case-control study. The control group comprised asymptomatic students in the same classes of the cases. The presence or absence of symptoms, ingestion of each food provided by school meal service, and commonly ingested foods in addition to those foods in meal service were investigated. Moreover, specimens collected from rectal swab, preserved foods, and environmental surface were tested.RESULTS: Of the 6,092 subjects, 1,111 (1,083 students, 22 school personnel, and 6 foodservice employees) were included in the case group; this corresponded to an 18.4% attack rate. Symptoms included diarrhea (n=1,051, 94.6%), abdominal pain (n=931, 83.8%), febrile sensation (n=502, 45.2%), and vomiting (n=275, 24.8%). The epidemic curves of each 10 schools were unimodal. Investigation of food intake showed a significantly high odds ratio for chocolate cake in 5 out of the 10 schools. Laboratory test detected Salmonella enterica serovar Thompson both in rectal swab specimens of 9 schools and in collected preserved chocolate cakes of 9 schools. Pulsed-field gel electrophoresis test result showed that Salmonella enterica seorvar Thompson isolated from human and foods were the same.CONCLUSIONS: The source of infection for the Salmonella enterica serovar Thompson outbreak in the 10 schools of Busan Metropolitan City is chocolate cake. Traceback investigation for origin of contaminated food in food-borne disease outbreak and safety control during food production should be more enhanced.


Subject(s)
Abdominal Pain , Cacao , Case-Control Studies , Diarrhea , Eating , Electrophoresis, Gel, Pulsed-Field , Food, Preserved , Foodborne Diseases , Gastroenteritis , Humans , Korea , Meals , Odds Ratio , Salmonella enterica , Salmonella Infections , Salmonella , Sensation , Serogroup , Vomiting
15.
Article in English | WPRIM | ID: wpr-758879

ABSTRACT

Sequence type (ST) 33 of Shiga toxin-producing Escherichia coli (STEC) strain O91:H14 has been proposed as a potential domestic clone of STEC in Korea because of its high prevalence among human patients with mild diarrhea or asymptomatic carriers. Herein, the clonal diversity of 17 STEC O91:H14 isolates of ST33 during 2003 to 2014 was analyzed by pulsed-field gel electrophoresis, including 14 isolates from human patients and 3 from retail meats. Their virulence characteristics, acid resistance, and antimicrobial susceptibility were also determined. Our results showed that all isolates were clustered mainly into three different pulsotypes and were likely low pathogenic without antimicrobial resistance.


Subject(s)
Clone Cells , Diarrhea , Electrophoresis, Gel, Pulsed-Field , Escherichia coli , Humans , Korea , Meat , Molecular Epidemiology , Prevalence , Shiga Toxin , Shiga-Toxigenic Escherichia coli , Virulence
16.
Rev. méd. Chile ; 147(1): 24-33, 2019. tab
Article in Spanish | LILACS | ID: biblio-991369

ABSTRACT

Background: Salmonella Heidelberg (S. Heidelberg) causes gastroenteritis and sometimes bacteremia and endocarditis. In other countries, this serovar has multidrug resistance including extended-spectrum β-lactamases (ESBLs) and AmpC (β-lactamases (AmpC), associated with the blaCMY-2 gene. In Chile, an outbreak by S. Heidelberg occurred in 2011, the phenotypic and genetic characteristics of Chilean strains are unknown. Aim: To determine the antimicrobial susceptibility, presence of plasmids and virulence factor genes in S. Heidelberg strains isolated in Chile over the period 2006-2011. Material and Methods: In sixty-one S. Heidelberg clinical and environmental strains collected by the Public Health Institute in Chile during 2006-2011, antimicrobial susceptibility, plasmids and virulence factor genes (invA, sifA, pefA, agfA, lpfA and, stkD) were studied. Results: S. Heidelberg had a high susceptibility to sulfamethoxazole-trimethoprim, gentamicin, ceftriaxone, ceftiofur, chloramphenicol, amoxicillin-clavulanic acid and ampicillin. However, 52% had decreased susceptibility to ciprofloxacin and 33% resistance to tetracycline. ESBLs were detected in three strains isolated from blood cultures, environment and human feces. The latter strain was positive for AmpC and blaCMY-2 gene. Fifty three of 61 strains showed one to seven plasmids of 0.8 to approximately 30 kb. Most plasmids were small with sizes between 0.8 and 2 kb. All isolates were positive for all genes except pefA. Conclusions: S. Heidelberg isolated from Chilean samples was susceptible to first-line antimicrobials, except tetracycline and ciprofloxacin. The emergence of strains with ESBLs and AmpC should be a warning. The strains were homogeneous for virulence genes, but heterogeneous in their plasmids.


Subject(s)
Humans , Plasmids/isolation & purification , Salmonella/isolation & purification , Salmonella/drug effects , Anti-Bacterial Agents/pharmacology , Reference Values , Salmonella/genetics , Salmonella/pathogenicity , Time Factors , Virulence , DNA, Bacterial , Microbial Sensitivity Tests , Chile , Electrophoresis, Gel, Pulsed-Field , Drug Resistance, Multiple, Bacterial , Environmental Microbiology
17.
Rev. Soc. Bras. Med. Trop ; 52: e20180285, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041544

ABSTRACT

Abstract INTRODUCTION Salmonella enterica serovar Panama belongs to the D1 serogroup and is frequently associated with nontyphoidal salmonellosis in humans. This study aimed to characterize isolates collected from Northeast Brazil by phenotypic and molecular methods. METHODS Forty four S. Panama strains were examined for antimicrobial susceptibility, virulence genes, and pulsed field gel electrophoresis (PFGE) types. RESULTS All strains were susceptible to antibiotics (except for streptomycin), presented classical virulence factors, and could be clustered into four groups and 18 pulsotypes. CONCLUSIONS This work calls for continuous surveillance for the emergence of antibiotic resistance and new clones in a geographical area.


Subject(s)
Animals , Salmonella enterica/genetics , Virulence Factors/genetics , Genetic Variation , Brazil , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Salmonella enterica/isolation & purification , Salmonella enterica/drug effects , Salmonella enterica/pathogenicity , Drug Resistance, Multiple, Bacterial , Anti-Bacterial Agents/pharmacology
18.
Rev. Soc. Bras. Med. Trop ; 52: e20190243, 2019. tab
Article in English | LILACS | ID: biblio-1020442

ABSTRACT

Abstract INTRODUCTION In recent decades, the prevalence of carbapenem-resistant Acinetobacter isolates has increased, and the production of oxacillinase (OXA)-type carbapenemases is the main mechanism underlying resistance. We evaluated OXA production from 114 Acinetobacter isolates collected between March and December 2013 from different clinical specimens of patients in two hospitals (Hospital 1 [n = 61] and Hospital 2 [n = 53]) located in Niterói, Rio de Janeiro, Brazil. We also evaluated the genetic diversity of OXA-producing isolates. METHODS All the isolates were identified through the automated system Vitek II and matrix-assisted laser desorption ionization-time of flight mass spectrometry MALDI-TOF MS as belonging to the A. baumannii-A. calcoaceticuscomplex. Antimicrobial susceptibility profiles were verified through agar diffusion tests. The presence of OXA-encoding genes was confirmed by PCR. The genetic diversity of isolates positive for carbapenemase production was analyzed through pulsed-field gel electrophoresis. RESULTS There was a high rate of resistance to carbapenems in the isolates (imipenem: 96%; meropenem: 92%) from both hospitals. Moreover, a high percentage (95.6%) of OXA-23-positive isolates was observed for both hospitals, indicating that this was the main mechanism of carbapenem-resistance among the studied population. In addition, most isolates (96.5%) were positive for bla OXA-51. A high genetic diversity and a few major genotypes were found among the OXA-23-positive isolates analyzed. Only intra-hospital dissemination was observed. CONCLUSIONS The elevated dissemination of bla OXA-23-like observed among Acinetobacter isolates from both the studied hospitals highlights the need for continuous epidemiological surveillance in these institutions.


Subject(s)
Humans , Acinetobacter/enzymology , beta-Lactamases/drug effects , Acinetobacter Infections/microbiology , Acinetobacter/drug effects , Acinetobacter/genetics , beta-Lactamases/biosynthesis , Brazil , DNA, Bacterial/genetics , Microbial Sensitivity Tests , Polymerase Chain Reaction , Bacterial Typing Techniques , Electrophoresis, Gel, Pulsed-Field , Hospitals, General , Anti-Bacterial Agents/pharmacology
19.
J. pediatr. (Rio J.) ; 94(4): 380-389, July-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-954633

ABSTRACT

Abstract Objective: Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. Method: A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. Results: A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p ≤ 0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). Conclusions: In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level.


Resumo Objetivo: O Staphylococcus aureus é responsável por um grande número de infecções na população pediátrica; contudo, as informações sobre o comportamento dessas infecções nessa população são limitadas. O objetivo do estudo foi descrever as características clínicas, epidemiológicas e moleculares de infecções causadas por Staphylococcus aureus suscetíveis e resistentes à meticilina (MSSA-MSRA) em uma população pediátrica. Método: Um estudo transversal descritivo foi realizado em pacientes entre 0 e 14 anos de idade de três instituições de alta complexidade (2008-2010). Todos os pacientes infectados com S. aureus resistentes à meticilina e uma amostra representativa de pacientes infectados com S. aureus suscetíveis à meticilina foram incluídos. As informações clínicas e epidemiológicas foram obtidas de prontuários médicos, e a caracterização molecular incluiu tipagem spa, Eletroforese em Gel de Campo Pulsado (PFGE) e Tipagem de sequências multilocus (MLST). Além disso, o Cassete Cromossômico Estafilocócico mec (SCCmec) e genes de fatores de virulência foram detectados. Resultados: 182 pacientes, 65 com infecções por S. aureus suscetíveis à meticilina e 117 com infecções por S. aureus resistentes à meticilina, foram incluídos no estudo; 41,4% dos pacientes com menos de um ano de idade. As infecções mais frequentes foram da pele e dos tecidos moles. Os históricos como internações em centros de atendimento e o uso prévio de antibióticos foram mais comuns em pacientes com infecções por S. aureus resistentes à meticilina (p ≤ 0,05). Dezesseis complexos clonais foram identificados, e as cepas de S. aureus suscetíveis à meticilina foram mais diversificadas. O cassete mais comum foi o Cassete Cromossômico Estafilocócicomec IVc (70,8%), relacionado à leucocidina de panton-valentine (pvl). Conclusões: Em comparação a outros locais, observamos uma prevalência de infecções em crianças com menos de um ano de idade na cidade; o que enfatiza a importância de conhecer a epidemiologia em nível local.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Skin Diseases, Infectious/microbiology , Staphylococcal Infections/microbiology , Soft Tissue Infections/microbiology , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Skin Diseases, Infectious/diagnosis , Staphylococcal Infections/diagnosis , Cross-Sectional Studies , Electrophoresis, Gel, Pulsed-Field , Soft Tissue Infections/diagnosis , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Multilocus Sequence Typing
20.
Mem. Inst. Invest. Cienc. Salud (Impr.) ; 16(2): 65-78, Ago. 2018. tab, ilus
Article in Spanish | LILACS, BDNPAR | ID: biblio-997981

ABSTRACT

Las Enfermedades de Transmisión Alimentaria (ETA) son un problema de salud pública con altos índices de morbilidad y mortalidad a nivel global. La vigilancia y estudio de brotes de las ETA a través de Electroforesis de Campo Pulsado (PFGE) constituye un soporte fundamental para la investigación epidemiológica. El objetivo del estudio es presentar la base de datos de perfiles genéticos bacterianos y analizar brotes de enfermedades transmitidas por alimentos empleando Electroforesis de Campo Pulsado. Estudio descriptivo observacional de carácter retrospectivo, muestreo por conveniencia en el que fueron estudiados 778 aislamientos bacterianos causantes de ETA. La Base de Datos Nacional (BDN) quedó conformada por los siguientes patógenos entéricos; Salmonella spp., Shigella sonnei, Vibrio cholerae, Campylobacter spp., Escherichia coli O157:H7 y Escherichia coli no O157 caracterizados por una diversidad de patrones únicos, clusters y brotes. La BDN de Salmonella spp., quedó representada por un total de 558 cepas con 248 PUN, de las cuales 22,6% (126 cepas) corresponden a Salmonella enterica ser. Typhimurium, 20,6% (115 cepas) a Salmonella enterica ser. Enteritidis, 9,1% (51 cepas) a Salmonella enterica ser. Newport, 1,6% (9 cepas) a Salmonella enterica ser. Muenchen, que al mismo tiempo son los serotipos que están asociados a brotes. Fueron confirmados un total de 13 brotes causados por Salmonella spp.; Shigella sonnei con 113 cepas estudiadas, 57 patrones únicos y 19 clusters detectados. Se identificaron 3 patrones PYJ16X01.0012, PYJ16X01.0034 y PYJ16X01.0014 como los predominantes. Vibrio cholerae con 18 cepas estudiadas, 9 patrones únicos y 4 clusters detectados. Se pudo establecer una relación genética del 100% entre cepas de Vibrio cholerae O1 biotipo El Tor serotipo Ogawa productora de toxinas ctxA y tcpA aislada del caso índice del brote de cólera. Campylobacter spp., con 62 cepas estudiadas, 42 patrones únicos y 10 clusters detectados. La BDN de E. coli productor de toxina shiga O157 y no O157, con 9 y 20 cepas de origen humano respectivamente, caracterizadas según sus factores de virulencia y subtipos. Se reconocieron 8 patrones electroforéticos PUN y 1 cluster para E. coli productor de toxina shiga O157, y 18 PUN y 1 clúster para E. coli productor de toxina shiga no O157.La disponibilidad de una Base de Datos Nacional de patógenos bacterianos transmitidos por alimentos constituye un importante avance para la salud pública, con un gran aporte en la vigilancia y epidemiología del país permitiendo la confirmación y detección de brotes discriminando aislamientos relacionados genéticamente y por consiguiente el estudio de relaciones clonales y probable origen(AU)


Foodborne diseases (FBD) are a problem of public health with high indexes of morbidity and mortality at global level. The surveillance and study of outbreaks of the FBD through pulsed field gel electrophoresis (PFGE) is a fundamental support for epidemiological research. The aim of the study is to present the database of bacterial genetic profiles and analyze outbreaks of FBD using PFGE. This was an observational descriptive retrospective study with convenience sampling in which 778 bacterial isolates causing FBD were studied. The National Database (NDB) was made up of the following enteric pathogens causing FBD: Salmonella spp., Shigella sonnei, Vibrio cholerae, Campylobacter spp., Escherichia coli O157: H7 and Escherichia coli no O157. Each of them was characterized by a diversity of unique patterns, clusters and outbreaks. The NDB of Salmonella spp. was represented by a total of 558 strains with 248 PUN, of which 22.6% (126 strains) correspond to Salmonella enterica ser. Typhimurium, 20.6% (115 strains) to Salmonella enterica ser. Enteritidis, 9.1% (51 strains) to Salmonella enterica ser. Newport, 1.6% (9 strains) to Salmonella enterica ser. Muenchen, which at the same time are the serotypes associated with outbreaks. A total of thirteen outbreaks caused by Salmonella spp., Shigella sonnei with 113 strains studied, 57 unique patterns and 19 clusters detected were confirmed. Three patterns PYJ16X01.0012, PYJ16X01.0034 and PYJ16X01.0014 were identified as the predominant. Vibrio cholerae with 18 strains studied, 9 unique patterns and 4 clusters were detected. A genetic relationship of 100% was established between strains of Vibrio cholerae O1 biotype El Tor serotype Ogawa toxin producer ctxA and tcpA isolated from the index case of the cholera outbreak. Campylobacter spp., with 62 strains studied, 42 unique patterns and 10 clusters were detected. The NDB of O157 and non-O157 Shiga toxin producing E. coli O157, with 9 and 20 strains of human origin respectively, were characterized according to their virulence factors and subtypes. We recognized 8 PUN electrophoretic patterns and 1 cluster for O157 Shiga toxin producing E. coli, and 18 PUN and 1 cluster for non-O157 Shiga toxin producing E. coli. The availability of a National Database of bacterial pathogens transmitted by food constitutes an important advance for public health, with a great contribution to the surveillance and epidemiology of the country allowing the confirmation and detection of outbreaks discriminating genetically related isolates and therefore, the study of clonal relationships and probable origin(AU)


Subject(s)
Electrophoresis, Gel, Pulsed-Field , Foodborne Diseases/microbiology , Gram-Negative Bacteria/genetics , Paraguay/epidemiology , Disease Outbreaks , Retrospective Studies , Foodborne Diseases/epidemiology
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