scholarly journals The Aquatic Environment as a Reservoir ofVibrio choleraeO1 in Hydrographic Basins of the State of Pernambuco, Brazil

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Carina Lucena Mendes-Marques ◽  
Vladimir da Mota Silveira Filho ◽  
Ana Paula Rocha da Costa ◽  
Mariana de Lira Nunes ◽  
Sandoval Vieira da Silva Filho ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Virulence Genes ◽  
Intergenic Spacer ◽  
Pulsed Field Gel Electrophoresis ◽  
N Gene ◽  
Intergenic Spacer Region ◽  
Quiescent Period ◽  
Pathogenic Genes ◽  
Culture Negative

After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4rfbN (serogroup O1) positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR); 2 of these were alsoctxA (cholera toxin) positive. From May to June 2012, 30V. choleraeO1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR), and pulsed field gel electrophoresis (PFGE). The isolates were positive for therfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012) and environmental strains from 2004 to 2005, indicating the permanence of endemicV. choleraeO1 in the region.

Low Potential Virulence Associated with Mutations in the inlA and prfA Genes in Listeria monocytogenes Isolated from Raw Retail Poultry Meat

2013 ◽  
Vol 76 (1) ◽  
pp. 129-132 ◽  
Author(s):  
VICTORIA LÓPEZ ◽  
JAIME NAVAS ◽  
JOAQUÍN V. MARTÍNEZ-SUÁREZ
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Poultry Meat ◽  
Pathogenic Potential ◽  
Molecular Serotyping ◽  
Potential Source ◽  
Raw Foods ◽  
Over Time

Packaged raw foods can represent a potential source of Listeria monocytogenes contamination when opened at home, and listeriosis is associated with the consumption of undercooked raw foods. The aim of this study was to characterize a group of L. monocytogenes strains isolated from 56 packages of raw chicken meat from a single brand in order to determine the diversity of the strains that dominate in a particular food over time, as well as their pathogenic potential. Forty (71%) samples were found to be positive for L. monocytogenes, and three isolates per sample were subjected to PCR molecular serotyping. Subtyping of 45 isolates from different manufacturing dates (n = 40) or different molecular serotype within the same sample (n = 5) identified 11 different L. monocytogenes subtypes as defined by pulsed-field gel electrophoresis and sequencing of virulence genes actA and inlA. Two of the subtypes accounted for 51% of the isolates. About 40% of isolates (three subtypes) were found to potentially present attenuated virulence because of the presence of mutations in the prfA and inlA genes.

scholarly journals Molecular characterization of Aeromonas spp. and Vibrio cholerae O1 isolated during a diarrhea outbreak

2012 ◽  
Vol 54 (6) ◽  
pp. 299-304 ◽  
Author(s):  
Carina Lucena Mendes-Marques ◽  
Larissa Mélo do Nascimento ◽  
Grace Nazareth Diogo Theophilo ◽  
Ernesto Hofer ◽  
Osvaldo Pompílio de Melo Neto ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Intergenic Spacer ◽  
Abundant Species ◽  
Environmental Isolates ◽  
Pathogenic Potential ◽  
Intergenic Spacer Region ◽  
Clonal Relatedness ◽  
Pathogenic Genes ◽  
Vibrio Cholerae O1 ◽  
Definition Of

This work aimed to assess pathogenic potential and clonal relatedness of Aeromonas sp. and Vibrio cholerae isolates recovered during a diarrhea outbreak in Brazil. Clinical and environmental isolates were investigated for the presence of known pathogenic genes and clonal relatedness was assessed by intergenic spacer region (ISR) 16S-23S amplification. Four Aeromonas genes (lip, exu, gcat, flaA/B) were found at high overall frequency in both clinical and environmental isolates although the lip gene was specifically absent from selected species. A fifth gene, aerA, was rarely found in A. caviae, the most abundant species. The ISR profile revealed high heterogeneity among the Aeromonas isolates and no correlation with species identification. In contrast, in all the V. cholerae isolates the four genes investigated (ctxA, tcpA, zot and ace) were amplified and revealed homogeneous ISR and RAPD profiles. Although Aeromonas isolates were the major enteric pathogen recovered, their ISR profiles are not compatible with a unique cause for the diarrhea events, while the clonal relationship clearly implicates V. cholerae in those cases from which it was isolated. These results reinforce the need for a better definition of the role of aeromonads in diarrhea and whether they benefit from co-infection with V. cholerae.

Listeria monocytogenes From Farm to Fork in a Brazilian Pork Production Chain

2020 ◽  
Vol 83 (3) ◽  
pp. 485-490 ◽  
Author(s):  
DANILO A. L. SILVA ◽  
CLARISSE V. BOTELHO ◽  
BRUNA T. F. MARTINS ◽  
RAFAELA M. TAVARES ◽  
ANDERSON C. CAMARGO ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Gel Electrophoresis ◽  
Virulence Genes ◽  
Pulsed Field Gel Electrophoresis ◽  
Control Measures ◽  
Production Chain ◽  
Pork Production ◽  
Pulsed Field ◽  
Genetic Profiles ◽  
Different Sources

ABSTRACT Listeria monocytogenes contamination was assessed in different steps of a pork production chain. Ten lots of pigs were sampled at termination barns, at slaughter (after bleeding, after buckling, after evisceration, and after final washing), at processing (knives, deboning tables, and employees' hands), and of end products (ribs, shoulder, ham, and sausage). All samples (n = 670) were subjected to L. monocytogenes detection, and the obtained isolates (n = 18, identified as Listeria spp.) were characterized by their biochemical characteristics, serogroups, virulence genes, pulsed-field gel electrophoresis profiles, antibiotic resistances (ampicillin, penicillin, gentamicin, and sulfamethoxazole-trimethoprim), and adhesion abilities. The results revealed the low occurrence of Listeria spp. in the evaluated pork production chain. However, four tested sausage samples (40%) were positive for Listeria spp., with L. monocytogenes identified in two (20%) of these samples. Ten isolates were identified as L. monocytogenes (eight from serogroup 1/2a or 3a and two from serogroup 4b, 4d, or 4e): all isolates were also positive for the virulence-related genes hlyA, iap, plcA, actA, inlA, inlB, inlC, and inlJ and susceptible to the tested antibiotics. One sausage sample was contaminated by both serogroups 1/2a or 3a and 4b, 4d, or 4e. Isolates from serogroup 1/2a or 3a obtained during visits 5 and 6 presented distinct genetic profiles by pulsed-field gel electrophoresis, indicating that contamination may come from different sources. The adhesion potential exhibited by Listeria spp. isolates (n = 18) ranged from weak (serogroup 4b, 4d, or 4e) to moderate (L. innocua and L. monocytogenes serogroup 1/2a or 3a). Despite the low occurrence of L. monocytogenes, pathogenic serogroups were detected in sausages, demanding control measures by the industry. HIGHLIGHTS

scholarly journals Correlation between geographic distance and genetic similarity in an international collection of bovine faecal Escherichia coli O157[ratio ]H7 isolates

2003 ◽  
Vol 131 (2) ◽  
pp. 923-930 ◽  
Author(s):  
M. A. DAVIS ◽  
D. D. HANCOCK ◽  
T. E. BESSER ◽  
D. H. RICE ◽  
C. J. HOVDE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Genetic Relatedness ◽  
Geographic Distance ◽  
Similarity Coefficient ◽  
Pulsed Field Gel Electrophoresis ◽  
Dice Similarity Coefficient ◽  
Escherichia Coli O157 ◽  
Molecular Studies

Evidence from epidemiological and molecular studies of bovine Escherichia coli O157[ratio ]H7 suggests that strains are frequently transmitted across wide geographic distances. To test this hypothesis, we compared the geographic and genetic distance of a set of international bovine Escherichia coli O157[ratio ]H7 isolates using the Mantel correlation. For a measure of genetic relatedness, pulsed-field gel electrophoresis of six different restriction enzyme digests was used to generate an average Dice similarity coefficient for each isolate pair. Geographic distance was calculated using latitude and longitude data for isolate source locations. The Mantel correlation between genetic similarity and the logarithm of geographic distance in kilometers was −0·21 (P<0·001). The low magnitude of the Mantel correlation indicates that transmission over long distances is common. The occurrence of isolates from different continents on the same cluster of the dendrogram also supports the idea that Escherichia coli O157[ratio ]H7 strains can be transferred with considerable frequency over global distances.

Comparative analysis ofShigella sonneibiotype g isolated from paediatric populations in Egypt, 1999–2005

2012 ◽  
Vol 141 (8) ◽  
pp. 1614-1624 ◽  
Author(s):  
J. DEJLI ◽  
R. A. NADA ◽  
A. MANSOUR ◽  
A. A. EL-MONIEM ◽  
M. O. WASFY ◽  
...  
Keyword(s):  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Susceptibility Testing ◽  
Biochemical Characterization ◽  
Multidrug Resistant ◽  
Pulsed Field Gel Electrophoresis ◽  
Antibiotic Susceptibility Testing ◽  
Severe Diarrhoea ◽  
Plasmid Profiling ◽  
High Degree

SUMMARYStrain characteristics of 51Shigella sonneiisolates obtained from children seeking medical care (MC) and 48 isolates recovered during a prospective diarrhoea birth cohort (BC) study were compared. Biochemical characterization and antibiotic susceptibility testing determined that allS. sonneiisolates were biotype g and multidrug-resistant. Plasmid profiling identified 15 closely related patterns andXbaI pulsed-field gel electrophoresis confirmed the high degree of genetic similarity between isolates. AllS.sonneiisolates harbouredipaHand class II integrase genes and 84·3 and 80% of the MC and BC isolates, respectively carried thesengene. Neither the class I integrase nor thesetgene was detected. Our results indicate thatS. sonneiisolates associated with severe diarrhoea were indistinguishable from those associated with mild diarrhoea. Additional genetic tests with greater discrimination might offer an opportunity to determine genetic differences within the globally disseminating biotype g clone.

scholarly journals Streptococcus pneumoniae serotype 3 genotypes in invasive isolates from Colombia

Biomédica ◽  
2021 ◽  
Vol 41 (2) ◽  
pp. 338-346
Author(s):  
Zonia Katerin Alarcón ◽  
Carolina Duarte ◽  
Olga Sanabria ◽  
Jaime Moreno
Keyword(s):  
Streptococcus Pneumoniae ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Genetic Similarity ◽  
Invasive Disease ◽  
Pulsed Field Gel Electrophoresis ◽  
Surveillance Program ◽  
National Surveillance ◽  
Capsular Type ◽  
Type 3

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.

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