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1.
Arch Virol ; 165(1): 43-51, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31676996

RESUMEN

Inclusion body hepatitis (IBH), hydropericardium syndrome (HS), and gizzard erosion (GE) are all economically important diseases in the poultry industry worldwide and are all caused by fowl aviadenovirus (FAdV). It is important to identify the serotype of the virus to differentiate these diseases. In the present study, a total of six recent FAdV serotypes were isolated and identified in broiler and broiler-breeder flocks in Izmir, Manisa, and Aydin provinces of the Aegean region of Turkey between January and March 2019. The viruses were isolated from livers and pooled organs of chickens using primary chicken embryo kidney cell cultures (CEKC). Virus isolates were identified by PCR amplification of the loop 1 (L1) variable region of the hexon gene followed by Sanger sequencing. Sequence analysis revealed the presence of both FAdV-D (serotype 11) and FAdV-E (serotype 8b). The viruses that were isolated were associated with IBH, which is typically characterized by gross lesions such as enlarged and pale yellow liver with multiple petechial hemorrhages. Histopathological examination also showed necrotizing hepatitis with intranuclear inclusion bodies in hepatocytes. This study is the first report of the isolation and identification of FAdV serotypes associated with IBH in commercial broilers and broiler-breeder flocks in Turkey. The results of sequence analysis showed that FAdV-8b and FAdV-11 were the circulating serotypes that caused recent field outbreaks of IBH in the Aegean region between January and March, 2019.


Asunto(s)
Infecciones por Adenoviridae/virología , Aviadenovirus/clasificación , Enfermedades de las Aves de Corral/virología , Análisis de Secuencia de ADN/métodos , Animales , Aviadenovirus/genética , Aviadenovirus/aislamiento & purificación , Células Cultivadas , Pollos , Cuerpos de Inclusión/virología , Riñón/citología , Riñón/virología , Hígado/virología , Filogenia , Serotipificación , Turquia
2.
Food Microbiol ; 85: 103280, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31500706

RESUMEN

Listeria monocytogenes causes severe diseases in humans, including febrile gastroenteritis and systemic infections that has a high mortality despite antibiotic treatment. This pathogen may cause massive outbreaks associated to the consumption of contaminated food products, which highlight its importance in public health. In the last decade, L. monocytogenes has emerged as a foodborne pathogen of major importance in Chile. A previous work showed that in Chile during 2008 and 2009, L. monocytogenes serotypes 1/2a, 1/2b and 4b were the most frequently identified in food and clinical strains. Here we report the molecular characterization of L. monocytogenes strains isolated from 2008 to 2017 in the country. Our results indicate that serotypes 1/2a, 1/2b and 4b continue to be the most commonly found in food products. In addition, we identify persistent and widespread PFGE subtypes. This study reports ten years of epidemiological surveillance ofL. monocytogenes in Chile.


Asunto(s)
Monitoreo Epidemiológico , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Listeria monocytogenes/genética , Listeriosis/epidemiología , Chile/epidemiología , Recuento de Colonia Microbiana , ADN Bacteriano/genética , Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/microbiología , Gastroenteritis/epidemiología , Gastroenteritis/microbiología , Variación Genética , Humanos , Listeria monocytogenes/patogenicidad , Productos de la Carne/microbiología , Epidemiología Molecular , Salud Pública , Serogrupo , Serotipificación , Factores de Virulencia/genética
3.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(11): 1403-1408, 2019 Nov 10.
Artículo en Chino | MEDLINE | ID: mdl-31838812

RESUMEN

Objective: To investigate the molecular characterization of adult diarrhea cases caused by enterotoxic Escherichia coli (ETEC) and explore the practical model of epidemiology for laboratory technique and data needs based on the surveillance network. Methods: Epidemiological design and sampling targeted adult cases ETEC caused diarrhea in epidemic season. The enterotoxin type, serogroup, resistance, colonization factor and molecular type of ETEC were identified. Multiple dynamic phenotypic characteristics of ETEC were indicated by multidimensional and multivariable data. Results: From 2016 to 2018, 84 eligible ETEC strains were detected. The dominant serums/toxins were O∶6 (STh), O∶25 (LT), O∶159 (STh), O∶153 (STh). O∶6 (STh+CS21), which replaced O∶25 and O∶159 as the popular clones in 2018. Six cases of O∶153 (STh+CFA/I+CS8+PT34) in outbreak in 2017 were imported ones. The resistance rates of ETEC strains detected in adults to sulfasoxazole, naproxinic acid, ampicillin and azithromycin were more than 30%, multidrug resistance (MDR) reached 58.3%. Serum/toxin types suggested that attenuated strains were more likely to become MDR. Molecular typing confirmed that the genetic similarity of the dominant clone of O∶6 serogroup (PT20-24) was higher than O∶25 and O∶159. There was a high correlation between the minimal inhibitory concentration (MIC) of azithromycin and the resistant gene mphA (87.5%, 28/32). O∶6 (STh+CS21+mphA) resistant clone was first detected in 2016. Conclusion: A new epidemic clone in adult ETEC diarrhea cases in Shanghai was O∶6 (STh+CS21+mphA). For the first time the association between azithromycin resistance gene mphA and a serum group of ETEC was observed. Multidimensional and multivariate analysis techniques based on epidemiology can help reveal the potential transmission pattern of ETEC for the accurate surveillance and early warning of outbreaks.


Asunto(s)
Antibacterianos/farmacología , Azitromicina/uso terapéutico , Diarrea/tratamiento farmacológico , Escherichia coli Enterotoxigénica/genética , Escherichia coli Enterotoxigénica/aislamiento & purificación , Enterotoxinas/análisis , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Adulto , China , Diarrea/microbiología , Farmacorresistencia Microbiana , Escherichia coli Enterotoxigénica/clasificación , Escherichia coli Enterotoxigénica/efectos de los fármacos , Enterotoxinas/genética , Proteínas de Escherichia coli/genética , Humanos , Pruebas de Sensibilidad Microbiana , Serogrupo , Serotipificación
4.
JAMA ; 322(24): 2399-2410, 2019 12 24.
Artículo en Inglés | MEDLINE | ID: mdl-31860046

RESUMEN

Importance: Invasive nontypeable Haemophilus influenzae (NTHi) infection among adults is typically associated with bacteremic pneumonia. Nontypeable H influenzae is genetically diverse and clusters of infection are uncommon. Objective: To evaluate an increase in invasive NTHi infection from 2017-2018 among HIV-infected men who have sex with men in metropolitan Atlanta, Georgia. Design, Setting, and Participants: A population-based surveillance study with a cohort substudy and descriptive epidemiological analysis identified adults aged 18 years or older with invasive NTHi infection (isolation of NTHi from a normally sterile site) between January 1, 2008, and December 31, 2018 (final date of follow-up). Exposures: Time period, HIV status, and genetic relatedness (ie, cluster status) of available NTHi isolates. Main Outcomes and Measures: The primary outcome was incidence of invasive NTHi infection (from 2008-2016 and 2017-2018) among persons with HIV and compared with NTHi infection from 2008-2018 among those without HIV. The secondary outcomes were assessed among those aged 18 to 55 years with invasive NTHi infection and included epidemiological, clinical, and geographic comparisons by cluster status. Results: Among 553 adults with invasive NTHi infection (median age, 66 years [Q1-Q3, 48-78 years]; 52% male; and 38% black), 60 cases occurred among persons with HIV. Incidence of invasive NTHi infection from 2017-2018 among persons with HIV (41.7 cases per 100 000) was significantly greater than from 2008-2016 among those with HIV (9.6 per 100 000; P < .001) and from 2008-2018 among those without HIV (1.1 per 100 000; P < .001). Among adults aged 18 to 55 years with invasive NTHi infections from 2017-2018 (n = 179), persons with HIV (n = 31) were significantly more likely than those from 2008-2018 without HIV (n = 124) to be male (94% vs 49%, respectively; P < .001), black (100% vs 53%; P < .001), and have septic arthritis (35% vs 1%; P < .001). Persons with HIV who had invasive NTHi infection from 2017-2018 (n = 31) were more likely than persons with HIV who had invasive NTHi infection from 2008-2016 (n = 24) to have septic arthritis (35% vs 4%, respectively; P = .01). Pulsed-field gel electrophoresis of 174 of 179 NTHi isolates from 18- to 55-year-olds identified 2 genetically distinct clonal groups: cluster 1 (C1; n = 24) and cluster 2 (C2; n = 23). Whole-genome sequencing confirmed 2 clonal lineages of NTHi infection and revealed all C1 isolates (but none of the C2 isolates) carried IS1016 (an insertion sequence associated with H influenzae capsule genes). Persons with HIV were significantly more likely to have C1 or C2 invasive NTHi infection from 2017-2018 (28/31 [90%]) compared with from 2008-2016 among persons with HIV (10/24 [42%]; P < .001) and compared with from 2008-2018 among those without HIV (9/119 [8%]; P < .001). Among persons with C1 or C2 invasive NTHi infection who had HIV (n = 38) (median age, 34.5 years; 100% male; 100% black; 82% men who have sex with men), 32 (84%) lived in 2 urban counties and an area of significant spatial aggregation was identified compared with those without C1 or C2 invasive NTHi infection. Conclusions and Relevance: Among persons with HIV in Atlanta, the incidence of invasive nontypeable H influenzae infection increased significantly from 2017-2018 compared with 2008-2016. Two unique but genetically related clonal strains were identified and were associated with septic arthritis among black men who have sex with men and who lived in geographic proximity.


Asunto(s)
Infecciones por VIH/complicaciones , Infecciones por Haemophilus/epidemiología , Haemophilus influenzae/genética , Adolescente , Adulto , Afroamericanos , Anciano , Artritis Infecciosa/etnología , Estudios de Cohortes , Georgia/epidemiología , Infecciones por Haemophilus/complicaciones , Infecciones por Haemophilus/etnología , Homosexualidad Masculina , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Filogenia , Vigilancia de la Población , Serotipificación , Adulto Joven
5.
MMWR Morb Mortal Wkly Rep ; 68(45): 1024-1028, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31725706

RESUMEN

Certification of global eradication of indigenous wild poliovirus type 2 occurred in 2015 and of type 3 in 2019. Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988 and broad use of live, attenuated oral poliovirus vaccine (OPV), the number of wild poliovirus cases has declined >99.99% (1). Genetically divergent vaccine-derived poliovirus* (VDPV) strains can emerge during vaccine use and spread in underimmunized populations, becoming circulating VDPV (cVDPV) strains, and resulting in outbreaks of paralytic poliomyelitis.† In April 2016, all oral polio vaccination switched from trivalent OPV (tOPV; containing vaccine virus types 1, 2, and 3) to bivalent OPV (bOPV; containing types 1 and 3) (2). Monovalent type 2 OPV (mOPV2) is used in response campaigns to control type 2 cVDPV (cVDPV2) outbreaks. This report presents data on cVDPV outbreaks detected during January 2018-June 2019 (as of September 30, 2019). Compared with January 2017-June 2018 (3), the number of reported cVDPV outbreaks more than tripled, from nine to 29; 25 (86%) of the outbreaks were caused by cVDPV2. The increase in the number of outbreaks in 2019 resulted from VDPV2 both inside and outside of mOPV2 response areas. GPEI is planning future use of a novel type 2 OPV, stabilized to decrease the likelihood of reversion to neurovirulence. However, all countries must maintain high population immunity to decrease the risk for cVDPV emergence. Cessation of all OPV use after certification of polio eradication will eliminate the risk for VDPV emergence.


Asunto(s)
Brotes de Enfermedades , Salud Global/estadística & datos numéricos , Poliomielitis/epidemiología , Vacuna Antipolio Oral/efectos adversos , Poliovirus/aislamiento & purificación , Humanos , Poliomielitis/etiología , Poliomielitis/prevención & control , Poliovirus/clasificación , Vacuna Antipolio Oral/administración & dosificación , Serotipificación
6.
Int J Food Microbiol ; 309: 108332, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31494483

RESUMEN

Vibrio parahaemolyticus is a major food-borne pathogen. V. parahaemolyticus infections are associated with various serotypes; to date, 71 K-serogroups of V. parahaemolyticus have been determined based on capsular polysaccharide (CPS) diversity. In this study, the capsular polysaccharide gene clusters (CPSgcs) of 55 K-serogroups were identified by whole-genome sequencing and analysis. These CPSgcs exhibit a high level of genetic diversity. A microsphere-based suspension array (MSA) was established for the detection and identification of 55 V. parahaemolyticus K-serogroups based on CPSgc-specific genes. To evaluate our array, a double-blind test with 120 clinical isolates was carried out. In addition, an in silico K-serotyping system was established based on V. parahaemolyticus CPSgc-specific genes. This system was then used to examine 845 publicly available V. parahaemolyticus genomes; the results demonstrated that 813 isolates belong to one of 43 K-serogroups. Taken together, these results demonstrate that the molecular system developed in this study is suitable for rapid serotyping of V. parahaemolyticus isolates from environmental and clinical samples. In addition, the system could be applied to epidemiological investigations of this important food-borne pathogen.


Asunto(s)
Cápsulas Bacterianas/genética , Enfermedades Transmitidas por los Alimentos/diagnóstico , Polisacáridos Bacterianos/genética , Serotipificación/métodos , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/inmunología , Cápsulas Bacterianas/inmunología , Método Doble Ciego , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Familia de Multigenes/genética , Polisacáridos Bacterianos/inmunología , Serogrupo , Vibriosis/diagnóstico , Vibrio parahaemolyticus/clasificación
7.
Int J Food Microbiol ; 310: 108289, 2019 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-31487606

RESUMEN

This study aimed to characterize serovar 1/2a, 1/2b, 1/2c and 4b of Listeria monocytogenes cultures based on High Resolution Melting (HRM) profiles, targeting 53 fragments in the region comprising prs, Listeria Pathogenicity Island-1 (LIPI-1) and ldh loci, and 28 fragments of inlAB operon. Fifty L. monocytogenes cultures (28 of lineage I, 22 of lineage II) were tested. Real time PCR and EvaGreen-based HRM assays were performed, and the HRM profile for each amplicon was compared to that of L. monocytogenes EGD-e strain. Considering all fragments tested, 45 HRM profiles were identified (Diversity Index = 99.35). Similarity analysis identified two main clusters: the first consisted of 25 cultures, including all 1/2a and 1/2c strains, except for three isolates from food of serovar 4b; the second group only included 1/2b and 4b isolates. Eighteen out of targeted amplicons showed constant HRM characteristics irrespective of the serovar/lineage, and hlyA displayed the most stable melting behavior. Conversely, thirteen amplicons were specific for 1/2b and 4b isolates, showing major variations within actA, followed by prs, prfA, mpl and plcB genes. A fragment targeting an intragenic region (part of plcA and part of an unknown gene) had a melting profile allowing differentiation between 4b and 1/2b isolates showing different Tm variants. Amplicons of inlA and inlB exhibited the largest intra-strain melting differences, and one inlB fragment could allow discriminating between 4b and 1/2b cultures, as well as between lineages. A greater level of genetic diversity amongst 1/2a cultures compared to 1/2c, 1/2b and 4b isolates was observed, with variations identified in LIPI-1, as well as within inlA and inlB genes. Sequencing analysis of amplicons with differential HRM profile from EGD-e confirmed point mutations. The study findings underlines that HRM-based approach may be useful for bacterial subtyping for epidemiological purposes when sequencing-based methods are not available.


Asunto(s)
Métodos Epidemiológicos , Microbiología de Alimentos/métodos , Listeria monocytogenes/clasificación , Listeria monocytogenes/genética , Serotipificación , Variación Genética , Islas Genómicas/genética , Humanos , Listeriosis/microbiología , Filogenia , Reproducibilidad de los Resultados , Serogrupo
8.
Int J Food Microbiol ; 308: 108305, 2019 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-31476731

RESUMEN

In recent years, the number of human salmonellosis cases in Western Australia (WA) has increased more dramatically than in any other Australian state. In 2017, the number of cases in WA was more than double the five-year average, and eggs had emerged as the key culprit for several Salmonella foodborne disease outbreaks. To better understand such an epidemiologically intriguing situation, our research goal was to investigate the prevalence, serovar diversity, multilocus sequence types, and antimicrobial resistance of non-typhoidal Salmonella contamination in retail eggs produced and sold in WA. A total of 200 visually clean and intact retail egg samples (each containing a dozen eggs) were purchased for one year (2017-2018) from supermarkets in metropolitan Perth, the capital of WA. For each sample, the contents and shells of the 12 eggs were separately pooled and cultured according to standard methods. Overall, Salmonella was detected in 11.5% (23/200) of the tested egg samples. Salmonella was isolated from 4.5% (9/200) and 3% (6/200) of eggshells and egg contents, respectively. In 4% (8/200) of the samples, Salmonella was recovered from both eggshell and egg contents. Isolates from positive retail egg samples were serotyped as either S. Typhimurium (52.2% [12/23]) or S. Infantis (39.1% [9/23]). Both serotypes were concurrently recovered from two different retail egg samples. We retained a set of both S. Typhimurium (n = 29) and S. Infantis (n = 12) isolates from all Salmonella-positive retail packs (n = 23) for further characterization. Only two (S. Typhimurium) isolates showed resistance to ampicillin, of which one carried ß-lactamase resistance gene blaTEM-1b. The remaining isolates (39/41) were susceptible to all 14 antimicrobials included in the minimum inhibitory concentrations (MICs) testing panel. Multilocus sequence typing and serotyping were perfectly mirrored, as all S. Typhimurium isolates were characterized as sequence type (ST)-19, and all S. Infantis isolates were ST-32. This study points to the noteworthy Salmonella prevalence rate in retail egg samples in WA. Our results illustrate minimal public health risks arising from antimicrobial resistance Salmonella from Australian eggs.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Cáscara de Huevo/microbiología , Huevos/microbiología , Microbiología de Alimentos/métodos , Salmonella/aislamiento & purificación , Animales , Australia , Genómica , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Salmonella/clasificación , Salmonella/genética , Intoxicación Alimentaria por Salmonella/epidemiología , Infecciones por Salmonella/epidemiología , Serogrupo , Serotipificación , Australia Occidental/epidemiología
10.
Epidemiol Mikrobiol Imunol ; 68(2): 75-81, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31398980

RESUMEN

AIM: The purpose of the surveillance performed from October to December in 2010-2017 was to monitor the trends in the susceptibility to beta-lactam and macrolide antibiotics in Streptococcus pneumoniae isolates from respiratory tract infections in the Czech Republic. MATERIAL AND METHODS: Between 42 and 55 laboratories participated in the study every year. Consecutive non-duplicate pneumococcal isolates from relevant microbiological specimens from patients with community-acquired bacterial respiratory tract infection were sequentially included in the study. Laboratories recorded qualitative results of penicillin and erythromycin susceptibility testing; susceptibility to antibiotics was determined by the disk diffusion method. Penicillin non-susceptible and/or erythromycin resistant isolates were referred to the National Reference Laboratory for Antibiotics, where the minimum inhibitory concentration of each antibiotic was tested using the broth microdilution method, and their serotyping was performed in the National Reference Laboratory for Streptococcal Infections. Twenty-six isolates from 2017 were analysed by the multilocus sequence typing method. RESULTS: In total, 7 491 pneumococcal strains were examined, of which 53.7% (4 023) were from the upper respiratory tract and 47.7% (3 573) from children under 15 years of age. Non-susceptibility to penicillin decreased from 2.6% in 2010 to 1.2% in 2017, while resistance to erythromycin increased from 7.4% to 9.7% over the same period. Penicillin non-susceptible isolates were mostly of serotypes 19A, 19F, and 15A. Macrolide resistant but penicillin susceptible isolates were predominantly represented by serotypes 19A and 3. The presence of the Taiwan19F-14 clone was confirmed in penicillin non-susceptible isolates by MLST, and the most frequently identified sequence type (ST) in macrolide resistant isolates was ST416 classified into the Netherlands15B-37 clone. CONCLUSIONS: The respiratory study of antibiotic resistance in S. pneumoniae confirmed the decreasing trend of resistance to penicillin but revealed a growing resistance to macrolide antibiotics in the Czech Republic. The results of our study confirm that antibiotic resistance in the vaccination era is associated primarily with the non-vaccine serotypes, and the clonal expansion of macrolide resistant serotype 19A was apparently supported by the growing prescription of macrolide antibiotics.


Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana , Infecciones Neumocócicas , Streptococcus pneumoniae , Adolescente , Antibacterianos/farmacología , Niño , República Checa/epidemiología , Farmacorresistencia Bacteriana Múltiple , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/microbiología , Serotipificación , Streptococcus pneumoniae/efectos de los fármacos
11.
Indian J Med Microbiol ; 37(1): 12-18, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31424004

RESUMEN

Purpose: Dengue viruses (DENVs), the causative agents of dengue (DEN), are classified into four serotypes and several genotypes. Identifying circulating serotypes and genotypes has clinical and epidemiological importance; however, limited information in this regard is available from Central India. This laboratory-based study was done to fill this lacuna. Materials and Methods: The samples collected in the acute phase of illness were subjected to DEN NS1 ELISA, and NS1-positive samples (n = 80) were subjected to serotyping; representative samples from each serotype were sequenced to identify genotypes. Results: Seventy-one (88.75%) samples could be serotyped. All the four DENV serotypes with dominance of DENV-3 (n = 33; 47%) were detected. DENV-4 was detected after a gap of 3 years. Cases with multiple DENV serotype infection were identified. Genotyping showed that DENV-1 belonging to genotype III, DENV-2 cosmopolitan (IV), DENV-3 genotype III lineage C and DENV-4 genotype I were in circulation in the year 2016. Conclusion: Our study documents the molecular characteristics of DENV circulating in the area. Detection of heterologous DENV serotype with dominance of DENV-3 emphasises the need for regular molecular monitoring.


Asunto(s)
Virus del Dengue , Dengue/epidemiología , Dengue/virología , Virus del Dengue/clasificación , Virus del Dengue/genética , Virus del Dengue/aislamiento & purificación , Brotes de Enfermedades/estadística & datos numéricos , Ensayo de Inmunoadsorción Enzimática , Genotipo , Glicoproteínas/genética , Humanos , India , ARN Viral/genética , Serotipificación , Proteínas no Estructurales Virales/genética
12.
Food Microbiol ; 84: 103273, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31421766

RESUMEN

Shiga toxin-producing Escherichia coli (STEC) are important pathogens transmitted by food that may cause severe illness in human beings. Thus, systems for STEC detection in food should have increasingly higher sensitivity and specificity. Here we compared six commercial systems for non-O157 STEC detection in meat and vegetables and determined their sensitivity, specificity and repeatability. A total of 46 samples (meat n = 23; chard n = 23) were experimentally contaminated with strains O26:H11, O45:H-, O103:H2, O111:NM, O121:H19 and O145:NM isolated in Argentina. Strain detection was confirmed by isolation according to ISO 13136:2012. Detection of the stx and eae genes in meat samples was highly satisfactory with all commercial kits, but only five had 100% sensitivity and specificity in chard. Of four kits evaluated for serogroup detection, three had 100% sensitivity and specificity, and one had 93.7% sensitivity and 100% specificity. All kits were adequate to analyze meat but not vegetable samples, and were not therefore validated for the latter matrix. The challenge for microbiology laboratories is to identify the advantages and disadvantages of the available kits for STEC detection in food based on a clear knowledge of the particular needs of each laboratory.


Asunto(s)
Contaminación de Alimentos/análisis , Microbiología de Alimentos/métodos , Carne/microbiología , Serotipificación/normas , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Verduras/microbiología , Adhesinas Bacterianas/genética , Microbiología de Alimentos/normas , Juego de Reactivos para Diagnóstico/normas , Sensibilidad y Especificidad , Serogrupo , Serotipificación/métodos , Toxina Shiga/genética
13.
Food Microbiol ; 84: 103268, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31421781

RESUMEN

Only a few studies concerning Shiga toxin-producing E. coli (STEC) detection in bivalves and their harvesting areas have been reported, and to the best of our knowledge there are no outbreaks associated with STEC from bivalves described. The aim of the present study was to investigate the occurrence of STEC in Norwegian bivalves, and to characterize potential STEC isolated from the samples. A total of 269 samples of bivalves were screened for the presence of stx and eae genes, and markers for the serogroups O26, O103, O111, O145 and O157 by using ISO TS 13136 (2012). The screening returned 19 samples that were positive for stx and eae, and attempts of isolation of STEC were made from these samples. Presumptive STEC were obtained from three samples, and three isolates (one from each sample) were subjected to whole-genome-sequencing (WGS). The WGS revealed that one of the isolates did not carry the stx genes, while the other two were identified as stx2i positive E. coli O9:H19 and stx2g positive E. coli O96:H19. Neither of the two STEC isolates were positive for virulence markers such as eae and ehx. The results suggest that the occurrence of STEC in Norwegian bivalves is low.


Asunto(s)
Bivalvos/microbiología , Alimentos Marinos/microbiología , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Animales , Proteínas de Escherichia coli/genética , Heces/microbiología , Noruega , Serogrupo , Serotipificación , Virulencia/genética
14.
Microbiol Immunol ; 63(11): 465-468, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31373400

RESUMEN

The potential role of wild boars as a source of erysipelas infection was investigated. An ELISA test of wild boar serum samples from 41 prefectures in Japan revealed that proportions of the Erysipelothrix rhusiopathiae-positive samples were very high in all the prefectures, and the mean positive rate was 95.6% (1312/1372). Serovars of E. rhusiopathiae isolates from wild boars were similar to those of previously reported swine isolates, and all serovar isolates tested were found to be pathogenic to mice. These results suggest that wild boars in Japan constitute a reservoir of E. rhusiopathiae and may pose risks to other animals.


Asunto(s)
Erysipelothrix/aislamiento & purificación , Erisipela Porcina/epidemiología , Erisipela Porcina/microbiología , Animales , Ensayo de Inmunoadsorción Enzimática , Erysipelothrix/clasificación , Erysipelothrix/patogenicidad , Japón/epidemiología , Ratones , Serogrupo , Serotipificación , Porcinos
15.
BMC Res Notes ; 12(1): 437, 2019 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-31324269

RESUMEN

OBJECTIVES: Group B Streptococcus (GBS) is an important opportunistic bacteria that causes a wide range of infections including neonatal sepsis, meningitis, pneumonia, soft tissue and urinary tract infections (UTI). The aim of this study was to evaluate the antimicrobial susceptibility patterns, surface proteins and capsular types of GBS isolates. RESULTS: 100 of UTI isolates were confirmed as GBS. Antimicrobial susceptibility pattern showed that 95% of GBS isolates were resistant to tetracycline, followed by erythromycin (52%), clindamycin (47%), levofloxacin (9%) and penicillin, cefepime, cefotaxime, and ceftriaxone each with (8%), and vancomycin 1%. Common capsular types were III, Ib, V, II, Ia and IV respectively and the distribution of surface protein genes was as follows: rib (40%), alpha-c (22%), alp2/3 (18%) and epsilon (15%), and alp4 gene was not detected in the isolates. Our findings showed the relationship between capsular types with Alpha-like proteins, as well as reduced sensitivity to antibiotics, so the performance of antibiotic surveillance programs is recommended.


Asunto(s)
Proteínas Bacterianas/metabolismo , Proteínas de la Membrana/metabolismo , Proteoma/metabolismo , Streptococcus agalactiae/metabolismo , Antibacterianos/clasificación , Antibacterianos/farmacología , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Genotipo , Humanos , Irán , Lipopolisacáridos/metabolismo , Proteínas de la Membrana/genética , Pruebas de Sensibilidad Microbiana , Proteoma/genética , Proteómica/métodos , Serotipificación , Infecciones Estreptocócicas/microbiología , Streptococcus agalactiae/genética , Streptococcus agalactiae/fisiología , Infecciones Urinarias/microbiología
16.
J Appl Microbiol ; 127(4): 1236-1245, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31330083

RESUMEN

AIMS: To develop a process risk model (PRM) for evaluating the safety of individual lots of ground chicken (GC) contaminated with Salmonella (Salm). METHODS AND RESULTS: Data for prevalence, number and serotype of Salm were collected with 25 g samples of GC using a combination of methods (whole sample enrichment, quantitative polymerase chain reaction, cultural isolation and serotyping). These data were used to develop a predictive model for Salm contamination of GC as a function of serving size from 25 to 300 g. This model was combined with a model for thermal inactivation of Salm in GC and a dose-response model for Salm to develop a PRM in Excel that was simulated with NeuralTools and @Risk. Of 100, 25 g samples of GC examined, 19 tested positive for Salm. Three serotypes were isolated: Infantis (n = 13), Enteritidis (n = 5) and Typhimurium (n = 1). The number of Salm ranged from 0 to 2·56 log with a median of 0·93 log per 25 g of GC. The PRM predicted that Salm prevalence would increase (P < 0·05) from 19 to 57% to 82 to 93% as serving size increased from 25 to 100 g to 200 to 300 g. However, the total number of Salm in a 100-kg lot of GC and total severity of illness (TSI) were not affected (P> 0·05) by serving size. The PRM was also used to evaluate effects of serving size distribution, cooking, food consumption behaviour, consumer demographics and Salmonella virulence on TSI. CONCLUSIONS: How a lot of GC is partitioned and consumed does not affect TSI. Scenario analysis demonstrated that the PRM can integrate prevalence, number and serotype data for Salm with consumer handling, consumption and demographics data to identify safe and unsafe lots of GC for improved food safety and public health. SIGNIFICANCE AND IMPACT OF THE STUDY: Process-risk models like the one developed in this study represent a new, holistic approach to food safety that holds great promise for improving public health and reducing food recalls.


Asunto(s)
Carne/microbiología , Salmonella , Animales , Pollos , Inocuidad de los Alimentos , Medición de Riesgo , Salmonella/clasificación , Salmonella/genética , Serotipificación
17.
Pan Afr Med J ; 32: 203, 2019.
Artículo en Francés | MEDLINE | ID: mdl-31312315

RESUMEN

Pneumococcal meningitis is a global scourge. It is a major cause of morbidity and mortality. In Morocco, 13-valent pneumococcal conjugate vaccine (PCV13) was introduced into the National Immunization Program in October 2010 according to the immunization schedule 2 + 1 and replaced by PCV10 in July 2012, according to the same schedule. Despite the use of the PCV13, which is essential in the fight against pneumococcal disease, the emergence of new non-vaccine serotypes always results in meningitis in children, causing serious sequelae. We report the case of an infant vaccinated with two doses of PCV13 with meningitis caused by Streptococcus pneumoniae serotype 7a. The peculiarity of this case study lies in pneumococcal meningitis due to Streptococcus pneumoniae serotype 7a not included in the PCV13 in an infant immunized by 2 doses of PCV13. We here insist on the need and the importance of an observatory for pneumococcal meningitis and of a wide epidemiological study in order to determine the serotypes in Morocco after the introduction of PCV13 and then of PCV10.


Asunto(s)
Meningitis Neumocócica/diagnóstico , Vacunas Neumococicas/administración & dosificación , Streptococcus pneumoniae/aislamiento & purificación , Humanos , Lactante , Masculino , Meningitis Neumocócica/microbiología , Meningitis Neumocócica/prevención & control , Marruecos , Vacunas Neumococicas/inmunología , Serotipificación , Streptococcus pneumoniae/inmunología , Vacunación
18.
J Med Microbiol ; 68(8): 1173-1188, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31268417

RESUMEN

PURPOSE: Correct serotype identification of Streptococcus pneumoniae (pneumococcus) is important for monitoring disease epidemiology and assessing the impacts of pneumococcal vaccines. Furthermore, correct identification and differentiation of the pathogenic S. pneumoniae from closely related commensal species of the mitis group of the genus Streptococcus are essential for correct serotype identification. METHODOLOGY: A new protocol for determining the existing 98 serotypes of pneumococcus was developed, applying two PCR amplifications and amplicon sequencing, using newly designed internal primers. The new protocol was validated using S. pneumoniae genome sequences, reference strains with confirmed serotypes and clinical isolates, and comparing the results with those from the traditional Quellung reaction or antiserum panel gel precipitation, in addition to real-time PCR analysis. The taxonomic identifications of 422 publicly available (GenBank) genome sequences of S. pneumoniae, Streptococcus pseudopneumoniae and Streptococcus mitis were assessed by whole-genome sequence average nucleotide identity based on blast (ANIb) analysis. RESULTS: The proposed sequetyping protocol generates a 1017 bp whole cpsB region sequence, increasing resolution for serotype identification in pneumococcus isolates. The identifications of all GenBank genome sequences of S. pneumoniae were confirmed, whereas most of the S. pseudopneumoniae and almost all of the S. mitis genome sequences did not fulfil the ANIb thresholds for species-level identification. The housekeeping biomarker gene, groEL, correctly identified S. pneumoniae but often misclassified S. pseudopneumoniae and S. mitis as S. pneumoniae. CONCLUSIONS: These studies affirm the importance of applying reliable identification protocols for S. pneumoniae before serotyping; our protocols provide reliable diagnostic tools, as well as an improved workflow, for serotype identification of pneumococcus and differentiation of serogroup 6 types.


Asunto(s)
Cápsulas Bacterianas/genética , Tipificación Molecular/métodos , Streptococcus pneumoniae/clasificación , Streptococcus pneumoniae/genética , Proteínas Bacterianas/genética , ADN Bacteriano/genética , Genoma Bacteriano/genética , Humanos , Infecciones Neumocócicas/microbiología , Proteínas Tirosina Fosfatasas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Serogrupo , Serotipificación/normas , Streptococcus/clasificación , Streptococcus/genética , Streptococcus/aislamiento & purificación , Streptococcus pneumoniae/aislamiento & purificación , Flujo de Trabajo
19.
Biomed Res Int ; 2019: 9530732, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31263711

RESUMEN

Considering the increasing popularity of reptiles as pets and their possible role as reservoirs of pathogenic microorganisms, the aim of this study was to isolate Escherichia coli, Salmonella spp., Clostridium perfringens, and C. difficile strains from reptiles in Brazil and to characterize the isolated strains. The characterization was based on phylogenetic typing of E. coli, identification of virulence genes of E. coli, C. perfringens, and C. difficile, serotyping of Salmonella spp., ribotyping and MLST of C. difficile and antimicrobial susceptibility test of pathogenic strains. Cloacal swabs were collected from 76 reptiles, of which 15 were lizards, 16 chelonians, and 45 snakes, either living in captivity, in the wild, or as companion animals. E. coli was isolated from 52 (68.4%) reptiles, of which 46 (88.4%) were characterized as phylogroup B1. The virulence factor CNF1 of E. coli was found in seven (9.2%) sampled animals, whereas the gene of EAST1 was found in isolates from two (2.6%) reptiles. Three isolates positive for CNF1 were resistant to cephalothin, one of which was also resistant to ciprofloxacin, trimethoprim/sulfamethoxazole, and chloramphenicol, being then classified as multidrug resistant strain (MDR). Salmonella enterica was identified in 26 (34.2%) reptiles, of which 13 belonged to the subspecies enterica. Serotypes such as S. Mbandaka, S. Panama, S. Infantis, S. Heidelberg, and S. Anatum were identified. One isolate of S. enterica subsp. houtenae was resistant to cephalothin and ciprofloxacin. C. perfringens type A was isolated from six (7.8%) animals. C. difficile was isolated from three (3.9%) reptiles. Two of these isolates were toxigenic and classified into ribotypes/MLST 081/ST9 and 106/ST42, which have been previously reported to infect humans. In conclusion, reptiles in Brazil can harbor toxigenic C. difficile and potentially pathogenic E. coli and Salmonella enterica subsp. enterica, thus representing a risk to human and animal health.


Asunto(s)
Clostridium difficile/aislamiento & purificación , Clostridium perfringens/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Reptiles/microbiología , Salmonella/aislamiento & purificación , Animales , Brasil , Clostridium difficile/clasificación , Clostridium perfringens/clasificación , Ecosistema , Escherichia coli/clasificación , Filogenia , Salmonella/clasificación , Serotipificación
20.
Eur J Clin Microbiol Infect Dis ; 38(10): 1883-1890, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31286288

RESUMEN

Determination of the capsule type of clinical isolates of Streptococcus pneumoniae is a prerequisite for epidemiological studies and further vaccine development. The Quellung reaction for serotyping is expensive and mostly done in reference centres. We wanted to evaluate whether Fourier-transformed infrared (FT-IR) spectroscopy is suitable for capsular type analysis and prediction of pneumococcal serotypes. We used the IR-Biotyper™ (Bruker) to create a database containing the spectra of 120 strains from invasive disease. The strains covered the 24 vaccine serotypes contained in the 13-valent conjugate vaccine (PCV13) and the 23-valent polysaccharide vaccine (PSV23). Hierarchical clustering analysis was performed. Finally, two different classification sets were created (PCV13 and PSV23). They were used to predict the serotype of 168 different challenge strains (invasive and non-invasive disease) covering 48 different serotypes (vaccine and non-vaccine types). FT-IR spectra from pneumococci (1300-800 cm-1) clustered along their serotype as determined by the Quellung reaction (120 strains, 24 different serotypes). Strains with unknown serotype fell within the cluster of the correct serotype, as long as the latter was represented in the database (168 strains, 48 different serotypes). Concordance between the Quellung reaction and FT-IR spectroscopy was excellent (kappa ≥ 0.75). FT-IR spectroscopy is a fast and cost-effective method to predict the capsular serotype of pneumococci.


Asunto(s)
Cápsulas Bacterianas/química , Infecciones Neumocócicas/diagnóstico , Serotipificación/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Streptococcus pneumoniae/química , Streptococcus pneumoniae/clasificación , Análisis por Conglomerados , Humanos
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