Prevalence and Genotyping of Commensal Neisseria with Reduced Susceptibility to Penicillin

2015 ◽  
Vol 25 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Arij Mechergui ◽  
Wafa Achour ◽  
Assia Ben Hassen
Keyword(s):  
Genetic Diversity ◽  
Elevated Level ◽  
Clinical Isolates ◽  
Penicillin Resistance ◽  
High Genetic Diversity ◽  
Clonal Relationship ◽  
Neutropenic Patients

We analyzed 85 <i>Neisseria </i>spp. strains collected by swabbing from neutropenic patients to determine the prevalence of reduced susceptibility to penicillin and to ascertain the clonal relationship between these strains. High genetic diversity and an elevated level of penicillin resistance were found among commensal <i>Neisseria </i>clinical isolates.

scholarly journals Diversity of cwp loci in clinical isolates of Clostridium difficile

2013 ◽  
Vol 62 (9) ◽  
pp. 1444-1452 ◽  
Author(s):  
Manuele Biazzo ◽  
Rossella Cioncada ◽  
Luigi Fiaschi ◽  
Vittorio Tedde ◽  
Patrizia Spigaglia ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Clostridium Difficile ◽  
Total Cell ◽  
The Other ◽  
Clinical Isolates ◽  
Cell Wall Proteins ◽  
High Genetic Diversity ◽  
Cell Extracts ◽  
Number Of Genes ◽  
Genes Encoding

An increased incidence of Clostridium difficile infection (CDI) is associated with the emergence of epidemic strains characterized by high genetic diversity. Among the factors that may have a role in CDI is a family of 29 paralogues, the cell-wall proteins (CWPs), which compose the outer layer of the bacterial cell and are likely to be involved in colonization. Previous studies have shown that 12 of the 29 cwp genes are clustered in the same region, named after slpA (cwp1), the slpA locus, whereas the remaining 17 paralogues are distributed throughout the genome. The variability of 14 of these 17 cwp paralogues was determined in 40 C. difficile clinical isolates belonging to six of the currently prevailing PCR ribotypes. Based on sequence conservation, these cwp genes were divided into two groups, one comprising nine cwp loci having highly conserved sequences in all isolates, and the other five loci showing low genetic conservation among isolates of the same PCR ribotype, as well as between different PCR ribotypes. Three conserved CWPs, Cwp16, Cwp18 and Cwp25, and two variable ones, Cwp26 and Cwp27, were characterized further by Western blot analysis of total cell extracts or surface-layer preparations of the C. difficile clinical isolates. Expression of genetically invariable CWPs was well conserved in all isolates, whilst genetically variable CWPs were not always expressed at comparable levels, even in strains containing identical sequences but belonging to different PCR ribotypes. This is the first report on the distribution and variability of a number of genes encoding CWPs in C. difficile.

scholarly journals Genetic Diversity and Population Structure of Vibrio parahaemolyticus Isolated From Clinical and Food Sources

2021 ◽  
Vol 12 ◽  
Author(s):  
Min He ◽  
Tao Lei ◽  
Fufeng Jiang ◽  
Jumei Zhang ◽  
Haiyan Zeng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Vibrio Parahaemolyticus ◽  
Large Scale ◽  
Foodborne Pathogen ◽  
Guangdong Province ◽  
Housekeeping Genes ◽  
Clinical Isolates ◽  
Food Sources ◽  
Clinical Samples ◽  
High Genetic Diversity

Vibrio parahaemolyticus is a common foodborne pathogen that causes gastroenteritis worldwide. Determining its prevalence and genetic diversity will minimize the risk of infection and the associated economic burden. Multilocus sequence typing (MLST) is an important tool for molecular epidemiology and population genetic studies of bacteria. Here, we analyzed the genetic and evolutionary relationships of 162 V. parahaemolyticus strains isolated in the Guangdong Province, China, using MLST. In the study, 120 strains were isolated from food samples, and 42 strains were isolated from clinical samples. All strains were categorized into 100 sequence types (STs), of which 58 were novel (48 from the food isolates and 10 from the clinical isolates). ST415 was the most prevalent ST among the food isolates, while ST3 was the most prevalent ST among the clinical isolates. Further, 12 clonal complexes, 14 doublets, and 73 singletons were identified in all ST clusters, indicating high genetic diversity of the analyzed strains. At the concatenated sequence level, non-synonymous sites in both, food and clinical isolates, were associated with purifying selection. Of note, the dN/dS ration was greater than 1 for some housekeeping genes in all isolates. This is the first time that some loci under positive selection were identified. These observations confirm frequent recombination events in V. parahaemolyticus. Recombination was much more important than mutation for genetic heterogeneity of the food isolates, but the probabilities of recombination and mutations were almost equal for the clinical isolates. Based on the phylogenetic analysis, the clinical isolates were concentrated in the maximum-likelihood tree, while the food isolates were heterogeneously distributed. In conclusion, the food and clinical isolates of V. parahaemolyticus from the Guangdong Province are similar, but show different evolutionary trends. This may help prevent large-scale spread of highly virulent strains and provides a genetic basis for the discovery of microevolutionary relationships in V. parahaemolyticus populations.

scholarly journals Genetic diversity of Streptococcus suis clinical isolates from pigs and humans in Italy (2003-2007)

2009 ◽  
Vol 14 (33) ◽  
Author(s):  
M S Princivalli ◽  
C Palmieri ◽  
G Magi ◽  
C Vignaroli ◽  
A Manzin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Antibiotic Resistance Genes ◽  
Streptococcus Suis ◽  
Invasive Disease ◽  
Clinical Isolates ◽  
High Genetic Diversity ◽  
Pork Products ◽  
Genotypic Analysis ◽  
Common Clinical Presentation ◽  
Industrialised Countries

Streptococcus suis, a major porcine pathogen, is emerging as a zoonotic agent capable of causing severe invasive disease in humans exposed to pigs or pork products. S. suis infection is rare in industrialised countries and usually arises as sporadic cases, with meningitis the most common clinical presentation in humans. Recent reports of two cases of meningitis in Sardinia and north-eastern Italy prompted this first characterisation of Italian S. suis isolates. Fifty-nine S. suis strains, the two recent human strains and 57 swine clinical isolates collected between 2003 and 2007 from different Italian herds and regions, were tested for antimicrobial susceptibility, PCR-screened for virulence and antibiotic resistance genes, and subjected to molecular typing. Phenotypic and genotypic analysis demonstrated an overall high genetic diversity among isolates, the majority of which were resistant to macrolides (78%) and tetracyclines (90%). The erm(B), tet(O), mosaic tet(O/W/32/O), tet(W), and tet(M) genes were detected. The tet(O/W/32/O) gene, the most frequent tet gene after tet(O), had never been described in the genus Streptococcus before. In addition, a virulent cps2, erm(B) tet(O) clone, belonging to sequence type 1 (ST1) of the ST1 complex, was found to be prevalent and persistent in Italian swine herds. Finally, the two human isolates (both ST1) carrying cps2, erm(B) and tet(W) were seen to be closely related to each other.

scholarly journals Genetic diversity and molecular analysis of metallo beta lactamases among imipenem resistant clinical isolates of Pseudomonas aeruginosa from Peshawar, Pakistan

2021 ◽  
Vol 37 (7) ◽  
Author(s):  
Amjad Ali ◽  
Kafeel Ahmad ◽  
Shaista Rahat ◽  
Israr Ahmad
Keyword(s):  
Genetic Diversity ◽  
Pseudomonas Aeruginosa ◽  
Molecular Analysis ◽  
Opportunistic Pathogen ◽  
Clinical Isolates ◽  
High Genetic Diversity ◽  
Beta Lactamases ◽  
Creative Commons ◽  
High Prevalence ◽  
Control And Prevention

Objectives: Pseudomonas aeruginosa is an opportunistic pathogen with remarkable adaptation ability to thrive in diverse environmental conditions. This study aimed at phenotypic and molecular analysis of metallo beta lactamases (blaIMP, blaVIM, blaNDM-1 and blaSPM-1) and genetic diversity analysis among imipenem resistant clinical isolates of Pseudomonas aeruginosa. Methods: This study was conducted from May 2017 to June 2018. The study included 187 Pseudomonas aeruginosa isolates collected from different clinical specimens from Peshawar, Pakistan. The isolates were analyzed for resistance to imipenem. Combined disc test (CDT) was then performed for phenotypic detection of metallo beta lactamases among imipenem resistant isolates of Pseudomonas aeruginosa. Molecular detection of metallo beta lactamases genes i.e. blaIMP, blaVIM, blaNDM-1 and blaSPM-1 was analyzed through polymerase chain reaction. Genetic diversity was determined through RAPD-PCR. Results: MBL production was observed in 76% (n=19) isolates. The occurrence of MBL genes blaIMP, blaNDM-1 and blaVIM was 68% (n=17), 48% (n=12), and 4% (n=1) respectively. The blaSPM-1 gene was not detected. High genetic diversity was observed in current study. Out of 182 isolates 171 isolates showed different RAPD profiles (93.95% polymorphism); 160 were unique RAPD strains and based on similarity coefficient ≥ 80%, 22 isolates were clustered into 11 distinct clones. Conclusion: A high prevalence of blaIMP and blaNDM-1 among imipenem resistant isolates of Pseudomonas aeruginosa is alarming that calls for proper control and prevention strategies. RAPD technique was found to be a good genotyping technique when limited resources are available. doi: https://doi.org/10.12669/pjms.37.7.4303 How to cite this:Ali A, Ahmad K, Rahat S, Ahmad I. Genetic diversity and molecular analysis of metallo beta lactamases among imipenem resistant clinical isolates of Pseudomonas aeruginosa from Peshawar, Pakistan. Pak J Med Sci. 2021;37(7):---------.  doi: https://doi.org/10.12669/pjms.37.7.4303 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

scholarly journals Subtype Characterization and Zoonotic Potential of Cryptosporidium felis in Cats in Guangdong and Shanghai, China

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 89
Author(s):  
Jiayu Li ◽  
Fuxian Yang ◽  
Ruobing Liang ◽  
Sheng Guo ◽  
Yaqiong Guo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Genetic Characterization ◽  
Zoonotic Potential ◽  
Common Occurrence ◽  
High Genetic Diversity ◽  
Gp60 Gene ◽  
The Common ◽  
Subtyping Tool

Cryptosporidiumfelis is an important cause of feline and human cryptosporidiosis. However, the transmission of this pathogen between humans and cats remains controversial, partially due to a lack of genetic characterization of isolates from cats. The present study was conducted to examine the genetic diversity of C. felis in cats in China and to assess their potential zoonotic transmission. A newly developed subtyping tool based on a sequence analysis of the 60-kDa glycoprotein (gp60) gene was employed to identify the subtypes of 30 cat-derived C. felis isolates from Guangdong and Shanghai. Altogether, 20 C. felis isolates were successfully subtyped. The results of the sequence alignment showed a high genetic diversity, with 13 novel subtypes and 2 known subtypes of the XIXa subtype family being identified. The known subtypes were previously detected in humans, while some of the subtypes formed well-supported subclusters with human-derived subtypes from other countries in a phylogenetic analysis of the gp60 sequences. The results of this study confirmed the high genetic diversity of the XIXa subtype family of C. felis. The common occurrence of this subtype family in both humans and cats suggests that there could be cross-species transmission of C. felis.

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