scholarly journals VIRULENCE GENE PROFILING AND PATHOGENICITY OF Streptococcus agalactiae ISOLATED FROM TILAPIA, Oreochromis niloticus FARMS IN INDONESIA

2021 ◽  
Vol 16 (2) ◽  
pp. 119
Author(s):  
Sukenda Sukenda ◽  
Achmad Suhermanto ◽  
Muhammad Zairin Jr. ◽  
Angela Mariana Lusiastuti ◽  
Sri Nuryati ◽  
...  
Keyword(s):  
Streptococcus Agalactiae ◽  
Virulence Genes ◽  
Disease Outbreaks ◽  
Virulence Gene ◽  
Gene Profiling ◽  
Pathogenicity Test ◽  
Post Injection ◽  
Gap Genes ◽  
Virulent Gene ◽  
Template Dna

Streptococcosis caused by Streptococcus agalactiae has become a major disease problem in tilapia culture in Indonesia. This study aimed to detect virulence genes of S. agalactiae during streptococcosis disease outbreaks in several tilapia farms in Indonesia and evaluate the correlation between biotype and virulence genes to bacterial virulence. The presence of virulence genes was determined in 10 strains of S. agalactiae isolated from farm-raised tilapia. Polymerase chain reaction (PCR) protocol was used to determine genes for cylE, hylB, lmb, bib A, PI-2b, fbs A, fbs B, gap, PI-1, and cfb in the template DNA. Pathogenicity test was carried out by intraperitoneal injection of 24 hour-cultured S. agalactiae to tilapia with 108 CFU/fish. Four isolates have seven of virulence genes (cylE, hylB, bibA, PI-2b, fbs A, fbs B, and gap genes), three isolates have six virulence genes (hylB, bib A, fbs A, fbs B, gap, cfb genes), one isolate has four virulence gene (hyl B, bib A, fbs, and cfb genes), and one isolate has one virulence gene (PI-2b gene). None of the isolates has lmb or PI-1 genes. Bacteria with more virulence genes showed higher pathogenicity post injection. Mortality of tilapia injected with b-hemolytic bacteria was 100% within the period of 14-19 hours, while non-hemolytic bacteria was 53.3%-86.6% on 14 days post-injection. Pathological changes associated with the infection by either isolate included melanosis, slow response, anorexia, ocular opacity, gasping, erratic, C-shape, and whirling. It can be concluded that S. agalactiae with more virulence genes show a higher level of pathogenicity. The presence of a virulent gene has the potential to be used as a basis for selecting candidate isolates and designing vaccine compositions as an effort to prevent streptococcosis infection in tilapia in Indonesia.

Virulence and antimicrobial resistance genes associated with the in-vivo pathogenicity of avian pathogenic E. coli isolates

2021 ◽  
Vol 1 (1) ◽  
pp. 17-20
Author(s):  
Ahmed Abd El-Mawgoud ◽  
Azza El-Sawah ◽  
Soad Nasef ◽  
Al-Hussien Dahshan ◽  
Ahmed Ali
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Broiler Chickens ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Health Concern ◽  
Pathogenicity Test ◽  
E Coli ◽  
Antimicrobial Resistance Genes

In the current study, ten avian pathogenic E. coli (APEC) isolates of the most predominant APEC serogroups isolated from broiler chickens in Egypt were screened for their virulence and antimicrobial resistance genes pattern using PCR. Five selected virulence gene patterns were further investigated for their in-vivo pathogenicity test. Results showed a 100% prevalence of the β-lactams and tetracyclines resistance genes. However, aminoglycoside and quinolone resistance genes were not detected. Also, 80% of the tested isolates harbored mcr-1 gene, colistin resistance gene. In-vivo pathogenic strains consistently harbored the virulence gene pattern of fimH, fimA, papC, iutA, and tsh. Additionally, the tsh gene was consistently detected with lethal APEC isolates in day-old chicks. These results highlighted the high prevalence of antimicrobial and virulence genes in APEC that potentially represent a public health concern. In this study, the virulence genes fimH, fimA, papC, iutA, and tsh were the most common virulence gene patterns associated with pathogenicity in day-old chicks.

Characterisation of multidrug resistant Escherichia coli isolated from two commercial lettuce and spinach supply chains

2021 ◽  
Author(s):  
Muneiwa T. Ratshilingano ◽  
Erika Margarete du Plessis ◽  
Stacey Duvenage ◽  
Lise Korsten
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Irrigation Water ◽  
Virulence Genes ◽  
Disease Outbreaks ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Water Sources ◽  
Point Of Sale ◽  
E Coli

ABSTRACT Leafy green vegetables have increasingly been reported as a reservoir of multidrug-resistant pathogenic Enterobacteriaceae; with Shiga toxin- producing Escherichia coli frequently implicated in disease outbreaks worldwide.  This study aimed to determine the presence and characteristics of antibiotic resistance, diarrheagenic virulence genes and phylogenetic groupings of E. coli isolates (n=51) from commercially produced lettuce and spinach from the farm, through processing and at the point of sale.  Multidrug resistance was observed in 33 of the 51 E. coli isolates (64.7%); with 35.7% (n=10/28) being generic and 100% (n=23/23) Extended Spectrum β-lactamase/AmpC- producing.  Resistance of E. coli isolates was observed against neomycin (100%; n=51/51), ampicillin (70.6%; n=36/51), amoxycilin (68.6%; n=35/51), tetracycline (45%; n=23/51), trimethoprim/ sulfamethoxazole (43%; n=22/51), chloramphenicol (25.5%; n=13/51), augmentin (11.8%; n=6/51) and gentamicin (7.8%; n=4/51); with 100% (n=51/51) susceptibility to imipenem. Virulence gene eae was detected in two E. coli isolates from irrigation water sources only, while none of the other virulence genes tested for were detected.   Most of the E. coli strains belonged to phylogenetic group B2 (25.5%; n=13), B1 (19.6%; n=10) and A (17.6%; n=9); with D (5.9%; n=3) less distributed. Although diarrheagenic E. coli were not detected, antibiotic resistance in E. coli prevalent in the supply chain was evident. Additionally, a clear link between E. coli isolates from irrigation water sources and leafy green vegetables through DNA fingerprinting was established which indicates the potential transfer of E. coli from irrigation water to minimally processed leafy green vegetables.

Molecular typing of Streptococcus agalactiae isolates of serotype Ia from tilapia in southern China

2019 ◽  
Vol 366 (13) ◽  
Author(s):  
Youlu Su ◽  
Chan Liu ◽  
Yiqin Deng ◽  
Changhong Cheng ◽  
Hongling Ma ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Streptococcus Agalactiae ◽  
Virulence Genes ◽  
Southern China ◽  
Virulence Gene ◽  
Economic Losses ◽  
Putative Virulence Gene ◽  
Gene Profiles ◽  
Multiplex Pcr Assay

ABSTRACT Streptococcus agalactiae is an important pathogen of tilapia causing enormous economic losses worldwide. In this study, multilocus sequence typing indicated that 75 S. agalactiae isolates from tilapia in southern China belonged to sequence type-7, as well as belonging to serotype Ia, as confirmed by multiplex PCR assay. The putative-virulence gene profiles and genetic variation of these strains were determined by three sets of multiplex PCR and multi-virulence locus sequencing typing (MVLST), respectively. Analysis of putative-virulence gene profiles showed that each strain harbored 18 putative-virulence genes but lacked lmb and scpB. Three putative-virulence genes (srr-1, bibA and fbsA) were further selected for MVLST analysis. Our data showed that the strains had 14 MVLST types (1–14) and clustered in three groups (Groups I–Ⅲ). The period of time during 2013 and 2014 was an important turning point for the differentiation of the putative-virulence genes of S. agalactiae, as type 1 within Group Ⅱ became the predominant MVLST type. There were significant differences in MVLST types of S. agalactiae isolated from different tilapia farming regions. MVLST assay may improve the discriminatory power and is suitable for understanding the epidemiology of S. agalactiae serotype Ia and screening multivalent vaccine candidate strains.

scholarly journals Escherichia coli Specific Virulence-Gene Markers Analysis for Quality Control of Ovine Cheese in Slovakia

2021 ◽  
Vol 9 (9) ◽  
pp. 1808
Author(s):  
Dobroslava Bujňáková ◽  
Lívia Karahutová ◽  
Vladimír Kmeť
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Disease Outbreaks ◽  
Virulence Gene ◽  
Phylogenetic Groups ◽  
Gene Markers ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Ovine Cheese ◽  
Phylogenetic Grouping

Shiga toxin-producing and extra-intestinal pathogenic Escherichia coli (E. coli) have the potential to spread through faecal waste, resulting in contamination of food and causing foodborne disease outbreaks. With the aim of characterizing unpasteurized ovine cheese in Slovakia, a total of 92 E. coli strains were examined for eleven representative virulence genes typical for (extra-)intestinal pathogenic E. coli and phylogenetic grouping. Phylogenetic groups B1 (36%) and A (32%) were the most dominant, followed by groups C (14%) and D (13%), while the lowest incidence was recorded for F (4%), and E (1%), and 43 (47%) samples carried at least one virulent gene, i.e., potential pathogens. Isolates present in groups E, F and D showed higher presence of virulence genes (100%, 75%, and 67%), versus 55%, 39%, and 28% in commensal B1, C, and A, respectively. Occurrence of papC and fyuA (both 24%) was highest, followed by tsh, iss, stx2, cnf1, kpsII, cvaC, stx1, iutA and eaeA. Nine E. coli strains (almost 10% of all tested and around 21% of our virulence-gene-associated isolates) harboured stx1, stx2 or eae. Ovine cheeses in Slovakia are highly contaminated with E. coli including potentially pathogenic strains capable of causing intestinal and/or extra-intestinal diseases, and thus may pose a threat to public health while unpasteurized.

scholarly journals The utility of multiple molecular methods including whole genome sequencing as tools to differentiate Escherichia coli O157:H7 outbreaks

2015 ◽  
Vol 20 (47) ◽  
Author(s):  
Byron M Berenger ◽  
Chrystal Berry ◽  
Trevor Peterson ◽  
Patrick Fach ◽  
Sabine Delannoy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Core Genome ◽  
Virulence Genes ◽  
Variable Number Tandem Repeat ◽  
Virulence Gene ◽  
Variable Number ◽  
Gene Profiling ◽  
Whole Genome

A standardised method for determining Escherichia coli O157:H7 strain relatedness using whole genome sequencing or virulence gene profiling is not yet established. We sought to assess the capacity of either high-throughput polymerase chain reaction (PCR) of 49 virulence genes, core-genome single nt variants (SNVs) or k-mer clustering to discriminate between outbreak-associated and sporadic E. coli O157:H7 isolates. Three outbreaks and multiple sporadic isolates from the province of Alberta, Canada were included in the study. Two of the outbreaks occurred concurrently in 2014 and one occurred in 2012. Pulsed-field gel electrophoresis (PFGE) and multilocus variable-number tandem repeat analysis (MLVA) were employed as comparator typing methods. The virulence gene profiles of isolates from the 2012 and 2014 Alberta outbreak events and contemporary sporadic isolates were mostly identical; therefore the set of virulence genes chosen in this study were not discriminatory enough to distinguish between outbreak clusters. Concordant with PFGE and MLVA results, core genome SNV and k-mer phylogenies clustered isolates from the 2012 and 2014 outbreaks as distinct events. k-mer phylogenies demonstrated increased discriminatory power compared with core SNV phylogenies. Prior to the widespread implementation of whole genome sequencing for routine public health use, issues surrounding cost, technical expertise, software standardisation, and data sharing/comparisons must be addressed.

scholarly journals High degree of virulence gene diversity in Streptococcus pyogenes isolated in Central Italy

2017 ◽  
Author(s):  
Daniela Bencardino ◽  
Maria Chiara Di Luca ◽  
Dezemona Petrelli ◽  
Manuela Prenna ◽  
Luca Agostino Vitali
Keyword(s):  
Streptococcus Pyogenes ◽  
Virulence Genes ◽  
Gene Diversity ◽  
Central Italy ◽  
Virulence Gene ◽  
T Antigen ◽  
Gene Profiling ◽  
Important Species ◽  
Multiple Loci ◽  
Genetic Features

AbstractGlobally, Streptococcus pyogenes poses a continuous burden on human health, causing both self-limiting and life-threatening diseases. Therefore, studying the profile of virulence genes and their combinations is essential to monitor the epidemiology and pathogenetic potential of this important species. Thus, the aim of this study was to analyze some genetic features of clinical strains collected in Italy in 2012.We conducted fibronectin-collagen-T antigen (FCT) region typing and emm typing in 122 S. pyogenes strains. Furthermore, several additional virulence genes were screened by polymerase chain reaction.We found correlations between emm types and FCT region profiles. emm1 strains were mainly associated with FCT2 and FCT6, while emm89 and emm12 strains were associated with FCT4. FCT5 was mainly represented in emm4, emm6, and emm75 strains. Noteworthy, we defined subtypes for each FCT type based on the differences in single and multiple loci compared to the reference scheme used for the classification of the FCT region. In addition, new FCT types were identified. Cluster analysis based on virulence gene profiling showed a non-random distribution within each emm type.This study showed the high variability of S. pyogenes strains and the great diversification that this pathogen has undergone during its evolution in the human host.

scholarly journals High virulence gene diversity in Streptococcus pyogenes isolated in Central Italy

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6613 ◽  
Author(s):  
Daniela Bencardino ◽  
Maria Chiara Di Luca ◽  
Dezemona Petrelli ◽  
Manuela Prenna ◽  
Luca Agostino Vitali
Keyword(s):  
Streptococcus Pyogenes ◽  
Virulence Genes ◽  
Gene Diversity ◽  
Central Italy ◽  
Virulence Gene ◽  
T Antigen ◽  
Gene Profiling ◽  
Pathogenic Potential ◽  
Important Species ◽  
Multiple Loci

Globally, Streptococcus pyogenes poses a continuous burden on human health, causing both self-limiting and life-threatening diseases. Therefore, studying the profile of virulence genes and their combinations is essential to monitor the epidemiology and pathogenic potential of this important species. Thus, the aim of this study was to analyze related genetic features of clinical strains collected in Italy in 2012 in order to obtain a valid picture of their virulence profile that could be compared to similar studies made in other countries approximately in the same period. We conducted emm typing and fibronectin-collagen-T antigen (FCT) region typing in 122 Streptococcus pyogenes strains. Furthermore, several additional virulence genes were screened by polymerase chain reaction. We found correlations between emm types and FCT region profiles. emm1 strains were mainly associated with FCT2 and FCT6, while emm89 and emm12 strains were associated with FCT4. FCT5 was mainly represented in emm4, emm6, and emm75 strains. Significantly, we defined subtypes for each FCT type based on the differences in single and double loci compared to the reference scheme used for the classification of the FCT region. In addition, new FCT-region variants with differences in multiple loci were also recorded. Cluster analysis based on virulence gene profiling showed a non-random distribution within each emm type. This study added new data to existing studies conducted worldwide and revealed new variability scores in circulating Streptococcus pyogenes strains and new assortments in well-established virulence gene signatures.

Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

scholarly journals Distribution of virulence genes and SCCmec types among methicillin-resistant Staphylococcus aureus of clinical and environmental origin: a study from community of Assam, India

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Deepshikha Bhowmik ◽  
Shiela Chetri ◽  
Bhaskar Jyoti Das ◽  
Debadatta Dhar Chanda ◽  
Amitabha Bhattacharjee
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Virulence Gene ◽  
Type I ◽  
Methicillin Resistant ◽  
Type Iv ◽  
Clinical Community ◽  
Type V ◽  
Sccmec Types

Abstract Objective This study was designed to discover the dissemination of virulence genes in Methicillin-resistant Staphylococcus aureus from clinical, community and environmental settings. Results This study includes 1165 isolates collected from hospital, community and environmental settings. Among them sixty three were confirmed as MRSA with varied SCCmec types viz; type I, type II, type III, type IV, type V, type VI, type VII, type VIII and type XII. The virulence gene such as sea (n = 54), seb (n = 21), eta (n = 27), etb (n = 2), cna (n = 24), ica (n = 2) and tst (n = 30) was also revealed from this study. The study underscores coexistence of resistance cassette and virulence genes among clinical and environment isolates which is first of its kind from this part of the world.

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