scholarly journals Salmonella enterica subsp. diarizonae Harboring ST233, ST1263, and ST1845 in Children

2021 ◽  
Vol 11 ◽  
Author(s):  
Mingming Zhou ◽  
Qiucheng Shi ◽  
Xiucai Zhang ◽  
Lingling Mei ◽  
Yihua Ye ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Iron Uptake ◽  
Virulence Genes ◽  
Antimicrobial Susceptibility Test ◽  
Microdilution Method ◽  
Magnesium Uptake ◽  
Typhoid Toxin ◽  
Sequence Types

ObjectiveThis study aims to analyze the molecular epidemiology, resistance, and pathogenicity of Salmonella enterica subsp. diarizonae isolated from children.MethodsWhole genome sequencing was carried out, and molecular serotypes, sequence types, resistance genes, and virulence genes of S. enterica subsp. diarizonae isolates were analyzed. Antimicrobial susceptibility test was determined by commercialized microdilution method.ResultsA total of three isolates of S. enterica subsp. diarizonae were isolated during 2015 to 2020. The molecular serotypes of the three strains were 61:c:z35, 61:l,v:1,5,7:[z57], and 65:k:z, respectively, and the sequence types were ST1845, ST233, and ST1263. All the three isolates were susceptible to ceftriaxone, ceftazidime, cefepime, amoxycillin/clavulanic acid, piperacillin/tazobactam, ertapenem, imipenem, levofloxacin, and trimethoprim/sulfamethoxazole. No other resistant gene was detected except aac(6’)-Iaa. There were no resistant plasmids detected in all the three isolates. A total of 76 genes were present in all isolates, containing 49 genes of Type III Secretion System (T3SS) mediated by SPI-1and SPI-2, 13 genes of adherence (type 1 fimbriae, Agf, and MisL-related genes), 11 genes of iron uptake (Yersiniabactin), two genes of magnesium uptake, and one gene of typhoid toxin(cdtB).ConclusionThe serotypes and sequence types of S. enterica subsp. diarizonae isolates were rarely reported in children; all the S. enterica subsp. diarizonae isolates were susceptible to detected antibiotics; T3SS, adherence, iron uptake, magnesium uptake, and typhoid toxin were responsible for pathogenicity of the S. enterica subsp. diarizonae isolates in children.

scholarly journals Secretion of the orgC Gene Product by Salmonella enterica Serovar Typhimurium

2003 ◽  
Vol 71 (11) ◽  
pp. 6680-6685 ◽  
Author(s):  
James B. Day ◽  
Catherine A. Lee
Keyword(s):  
Gene Product ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Type Iii Secretion System ◽  
Pathogenicity Island ◽  
Secretion System ◽  
Serovar Typhimurium ◽  
Transposon Insertions

ABSTRACT HilA activates the transcription of genes on Salmonella pathogenicity island 1 (SPI1), which encodes a type III secretion system (TTSS). Previous studies showed that transposon insertions in orgC, a gene located on SPI1, increase hilA expression. We characterize the orgC gene product and show that it is secreted via the SPI1 TTSS. We propose a model whereby OrgC functions as a secreted repressor of the SPI1 virulence genes.

scholarly journals Characterisation of Staphylococcus aureus isolated from rabbits in Fujian, China

2019 ◽  
Vol 147 ◽  
Author(s):  
J. Wang ◽  
L. Sang ◽  
S. Sun ◽  
Y. Chen ◽  
D. Chen ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Virulence Genes ◽  
Susceptibility Test ◽  
Antimicrobial Susceptibility Test ◽  
Fujian Province ◽  
Genetic Characteristics ◽  
Resistance Rates ◽  
Sequence Types

Abstract Staphylococcus aureus has been recognised as one of the important zoonotic pathogens. However, knowledge about the epidemiology and genetic characteristics of S. aureus in rabbits was limited. The aim of this study was to determine the characteristics of 281 S. aureus isolated from dead rabbits of nine rabbit farms in Fujian Province, China. All the isolates were characterised by multi-locus sequencing typing, detection of virulence factors and antimicrobial susceptibility test. The results showed that the 281 isolates were grouped into two sequence types, ST121 (13.52%, 38/281) and ST398 (86.48%, 243/281). Surprisingly, the ST121 strains were only recovered from the lung samples from one of the nine rabbit farms studied. In the 281 isolates, the virulence genes of nuc, hla, hlb, clfA, clfB and fnbpA were positive, whereas the sea, seb, tsst, eta and etb genes were negative. Notably, the 38 ST121 isolates carried the pvl gene. All the 281 isolates were methicillin-susceptible S. aureus, and the isolates were susceptible to most of the used antibiotics, except for streptomycin, kanamycin, azithromycin and penicillin, and the resistance rates of which were 23.84%, 19.57%, 16.01% and 11.03%, respectively. This study first described the epidemiology and characteristics of S. aureus in rabbits in Fujian Province, which will help in tracking the evolution of epidemic strains and preventing the rabbit–human transmission events.

scholarly journals Distribution of Virulence-Associated Genes and Genetic Relationships in Non-O1/O139 Vibrio cholerae Aquatic Isolates from China

2014 ◽  
Vol 80 (16) ◽  
pp. 4987-4992 ◽  
Author(s):  
Fengjuan Li ◽  
Pengcheng Du ◽  
Baisheng Li ◽  
Changwen Ke ◽  
Aiping Chen ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Type Iii Secretion ◽  
Virulence Genes ◽  
Genetic Relationships ◽  
Genotypic Diversity ◽  
Open Reading Frames ◽  
Content Type ◽  
Ctx Prophage ◽  
Sequence Types ◽  
Reading Frames

ABSTRACTNon-O1/O139Vibrio choleraeis naturally present in aquatic ecosystems and has been linked with cholera-like diarrhea and local outbreaks. The distribution of virulence-associated genes and genetic relationships among aquatic isolates from China are largely unknown. In this study, 295 aquatic isolates ofV. choleraenon-O1/O139 serogroups from different regions in China were investigated. Only one isolate was positive forctxBand harbored a rare genotype; 10 (3.4%) isolates carried several types ofrstRsequences, eight of which carried rare types of toxin-coregulated pili (tcpA). Furthermore, 16 (5.4%) isolates carried incomplete (with partial open reading frames [ORFs]) vibrio seventh pandemic island I (VSP-I) or VSP-II clusters, which were further classified as 11 novel types. PCR-based analyses revealed remarkable variations in the distribution of putative virulence genes, includingmshA(95.6%),hlyA(95.3%),rtxC(89.8%),rtxA(82.7%), IS1004 (52.9%),chxA(30.2%), SXT (15.3%), type III secretion system (18.0%), and NAG-ST (3.7%) genes. There was no correlation between the prevalence of putative virulence genes and that of CTX prophage or TCP genes, whereas there were correlations among the putative virulence genes. Further multilocus sequence typing (MLST) placed selected isolates (n= 70) into 69 unique sequence types (STs), which were different from those of the toxigenic O1 and O139 counterparts, and each isolate occupied a different position in the MLST tree. TheV. choleraenon-O1/O139 aquatic isolates predominant in China have high genotypic diversity; these strains constitute a reservoir of potential virulence genes, which may contribute to evolution of pathogenic isolates.

scholarly journals Molecular characterization of Salmonella enterica from poultry farms in Ilorin, north-central Nigeria

2021 ◽  
Vol 19 (3) ◽  
pp. 197-207
Author(s):  
I.A. Raufu ◽  
O.A. Ahmed ◽  
A. Aremu ◽  
J.A. Ameh ◽  
A. Ambali
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Occurrence Rate ◽  
Poultry Production ◽  
Potential Health ◽  
North Central ◽  
Antimicrobial Resistance Genes ◽  
Poultry Farms ◽  
Sequence Types

Poultry salmonellosis caused by Salmonella enterica is one of the most important bacterial diseases posing serious challenges to poultry production and human health worldwide. This study investigated the occurrence, serotypes, multilocus sequence types (MLSTs), antimicrobial resistance, plasmids, and 12 selected virulence genes of non-typhoidal Salmonella from poultry layer farms using whole-genome sequencing (WGS) methods. Two hundred cloaca swab samples were aseptically collected from four commercial poultry farms (layers) and transferred in sterile universal bottles on ice to the laboratory for analysis. Presumptive Salmonella isolates were detected with selective media and conventional biochemical tests. Serovars were confirmed by serotyping using the slide agglutination and Seqsero methods. Seven samples were positive for Salmonella consisting of Salmonella Typhimurium (S. Typhimurium) (n = 4), S. Albany (n = 2), and S. Agama with an occurrence rate of 3.5 % (7/200). Overall, 3 isolates showed the parC mutation expected not to cause resistance. Similarly, one S. Typhimurium isolate carried plasmid replicons of IncFIB(S)/IncFII(S) type without antimicrobial resistance genes. Three sequence types (STs); 19 (S. Typhimurium), 5317 (S. Albany), and 467 (S. Agama) were obtained. Salmonella Agama harboured 12 virulence genes, while S. Typhimurium and S. Albany harboured 11 virulence genes each. This study highlights the importance of S. Typhimurium, S. Albany, and S. Agama as major pathogens associated with poultry farms in Ilorin, north-central Nigeria. It equally provided baseline information on the serovar distribution, STs, resistance and the virulence gene profiles of all the serovars. Therefore, chickens can serve as a potential source of Salmonella transmission to humans, and this constitutes a potential health risk to the human population. Hence, there is a need for a specific Salmonella control program to be instituted as part of a national food safety strategy.

scholarly journals Presence of β-Lactamase-producing Enterobacterales and Salmonella Isolates in Marine Mammals

2021 ◽  
Vol 22 (11) ◽  
pp. 5905
Author(s):  
Olivia M. Grünzweil ◽  
Lauren Palmer ◽  
Adriana Cabal ◽  
Michael P. Szostak ◽  
Werner Ruppitsch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Marine Mammals ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Healthcare Sector ◽  
Whole Genome ◽  
E Coli ◽  
High Prevalence ◽  
Lactamase Gene ◽  
Sequence Types

Marine mammals have been described as sentinels of the health of marine ecosystems. Therefore, the aim of this study was to investigate (i) the presence of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacterales, which comprise several bacterial families important to the healthcare sector, as well as (ii) the presence of Salmonella in these coastal animals. The antimicrobial resistance pheno- and genotypes, as well as biocide susceptibility of Enterobacterales isolated from stranded marine mammals, were determined prior to their rehabilitation. All E. coli isolates (n = 27) were screened for virulence genes via DNA-based microarray, and twelve selected E. coli isolates were analyzed by whole-genome sequencing. Seventy-one percent of the Enterobacterales isolates exhibited a multidrug-resistant (MDR) pheno- and genotype. The gene blaCMY (n = 51) was the predominant β-lactamase gene. In addition, blaTEM-1 (n = 38), blaSHV-33 (n = 8), blaCTX-M-15 (n = 7), blaOXA-1 (n = 7), blaSHV-11 (n = 3), and blaDHA-1 (n = 2) were detected. The most prevalent non-β-lactamase genes were sul2 (n = 38), strA (n = 34), strB (n = 34), and tet(A) (n = 34). Escherichia coli isolates belonging to the pandemic sequence types (STs) ST38, ST167, and ST648 were identified. Among Salmonella isolates (n = 18), S. Havana was the most prevalent serotype. The present study revealed a high prevalence of MDR bacteria and the presence of pandemic high-risk clones, both of which are indicators of anthropogenic antimicrobial pollution, in marine mammals.

scholarly journals Virulence and Antimicrobial Resistance Profiles of Salmonella enterica Serovars Isolated from Chicken at Wet Markets in Dhaka, Bangladesh

2021 ◽  
Vol 9 (5) ◽  
pp. 952
Author(s):  
Nure Alam Siddiky ◽  
Md Samun Sarker ◽  
Md. Shahidur Rahman Khan ◽  
Ruhena Begum ◽  
Md. Ehsanul Kabir ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Salmonella Enterica ◽  
Virulence Genes ◽  
Health Concern ◽  
Production Cycle ◽  
Salmonella Spp ◽  
Native Chicken ◽  
Resistance Patterns ◽  
Research Findings ◽  
Native Chickens

Virulent and multi drug resistant (MDR) Salmonellaenterica is a foremost cause of foodborne diseases and had serious public health concern globally. The present study was undertaken to identify the pathogenicity and antimicrobial resistance (AMR) profiles of Salmonellaenterica serovars recovered from chicken at wet markets in Dhaka, Bangladesh. A total of 870 cecal contents of broiler, sonali, and native chickens were collected from 29 wet markets. The overall prevalence of S. Typhimurium, S. Enteritidis, and untyped Salmonella spp., were found to be 3.67%, 0.57%, and 1.95% respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namely invA, agfA, IpfA, hilA, sivH, sefA, sopE, and spvC. S. Enteritidis isolates carried all virulence genes whilst S. Typhimurium isolates carried six virulence genes except sefA and spvC. A diverse phenotypic and genotypic AMR pattern was found. Harmonic descending trends of resistance patterns were observed among the broiler, sonali, and native chickens. Interestingly, virulent and MDR Salmonella enterica serovars were found in native chicken, although antimicrobials were not used in their production cycle. The research findings anticipate that virulent and MDR Salmonella enterica are roaming in the wet markets which can easily anchor to the vendor, consumers, and in the food chain.

scholarly journals Positive regulation of Type III secretion effectors and virulence by RyhB paralogs in Salmonella enterica serovar Enteritidis

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Binjie Chen ◽  
Xianchen Meng ◽  
Jie Ni ◽  
Mengping He ◽  
Yanfei Chen ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Intestinal Epithelial Cells ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Intestinal Epithelial ◽  
Type Iii ◽  
Effector Gene ◽  
T3ss Effector

AbstractSmall non-coding RNA RyhB is a key regulator of iron homeostasis in bacteria by sensing iron availability in the environment. Although RyhB is known to influence bacterial virulence by interacting with iron metabolism related regulators, its interaction with virulence genes, especially the Type III secretion system (T3SS), has not been reported. Here, we demonstrate that two RyhB paralogs of Salmonella enterica serovar Enteritidis upregulate Type III secretion system (T3SS) effectors, and consequently affect Salmonella invasion into intestinal epithelial cells. Specifically, we found that RyhB-1 modulate Salmonella response to stress condition of iron deficiency and hypoxia, and stress in simulated intestinal environment (SIE). Under SIE culture conditions, both RyhB-1 and RyhB-2 are drastically induced and directly upregulate the expression of T3SS effector gene sipA by interacting with its 5′ untranslated region (5′ UTR) via an incomplete base-pairing mechanism. In addition, the RyhB paralogs upregulate the expression of T3SS effector gene sopE. By regulating the invasion-related genes, RyhBs in turn affect the ability of S. Enteritidis to adhere to and invade into intestinal epithelial cells. Our findings provide evidence that RyhBs function as critical virulence factors by directly regulating virulence-related gene expression. Thus, inhibition of RyhBs may be a potential strategy to attenuate Salmonella.

scholarly journals Antimicrobial susceptibility and diarrheagenic diagnosis of Escherichia coli and Salmonella enterica isolated from feral pigeons (Columba livia) captured in Fortaleza, Brazil

2018 ◽  
Vol 38 (11) ◽  
pp. 2150-2154 ◽  
Author(s):  
Ruben V. Horn ◽  
Windleyanne G.A. Bezerra ◽  
Elisângela S. Lopes ◽  
Régis S.C. Teixeira ◽  
Isaac N.G. Silva ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Clavulanic Acid ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Columba Livia ◽  
Susceptibility Test ◽  
Antimicrobial Susceptibility Test ◽  
E Coli ◽  
Feral Pigeons

ABSTRACT: This study aimed to isolate Escherichia coli and Salmonella enterica from captured feral pigeons in Fortaleza, Brazil, and, in addition to evaluate the antimicrobial susceptibility profiles and diagnose diarrheagenic E. coli strains. Pigeons were captured in four public locations in Fortaleza with three techniques. Individual cloacal swab samples were collected and submitted to bacterial isolation, biochemical identification and antimicrobial susceptibility test. Disk diffusion technique was used with twelve antibiotics. E. coli strains were submitted to DNA extraction followed by PCR to diagnose five diarrheagenic pathotypes. A total of 124 birds were captured. One bird was positive for Salmonella enterica (0.81%) and 121 (97.58%) were positive for E. coli. Among these, 110 isolates were submitted to antimicrobial susceptibility test and 28.18% (31/110) presented resistance to at least one antibiotic. Resistance to azithromycin was the most frequent (21.82%), followed by tetracycline (10.91%) and sulfamethoxazole with trimethoprim (8.9%). Multidrug resistance, calculated as a resistance to at least 3 antimicrobial classes, was identified in 3.64% (4/110) of strains. The maximum number of antimicrobial classes to which one strain was resistant was seven. Results demonstrated nine different resistance profiles and the most frequent was tetracycline and sulfamethoxazole with trimethoprim (4 strains), followed by chloramphenicol, azithromycin, tetracycline and sulfamethoxazole with trimethoprim (3 strains). Amoxicillin with clavulanic acid and tobramycin presented lowest levels of antimicrobial resistance, to which none of the tested strains were resistant. A single strain was positive for the eltB gene, which is a diagnostic tool to identify the Enterotoxigenic E. coli (ETEC) pathotype. None of the other investigated genes (stx1, stx2, estA, eaeA, ipaH, aatA and aaiC) were identified. The single isolate of S. enterica was a rough strain of Salmonella enterica subsp. enterica, but serotype identification was not possible. However, this isolate presented resistance to amoxicillin, amoxicillin with clavulanic acid, tetracycline and sulfamethoxazole with trimethoprim. Therefore, captured feral pigeons of Fortaleza presented a low prevalence of S. enterica and diarrheagenic E. coli. Considering the investigated pathogens, our results suggest a good health status and a low public health risk. However, important antimicrobial resistance profiles were identified.

scholarly journals A Salmonella Virulence Factor Activates the NOD1/NOD2 Signaling Pathway

mBio ◽  
2011 ◽  
Vol 2 (6) ◽  
Author(s):  
A. Marijke Keestra ◽  
Maria G. Winter ◽  
Daisy Klein-Douwel ◽  
Mariana N. Xavier ◽  
Sebastian E. Winter ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Content Type ◽  
Type Iii

ABSTRACTThe invasion-associated type III secretion system (T3SS-1) ofSalmonella entericaserotype Typhimurium (S. Typhimurium) activates the transcription factor NF-κB in tissue culture cells and induces inflammatory responses in animal models through unknown mechanisms. Here we show that bacterial delivery or ectopic expression of SipA, a T3SS-1-translocated protein, led to the activation of the NOD1/NOD2 signaling pathway and consequent RIP2-mediated induction of NF-κB-dependent inflammatory responses. SipA-mediated activation of NOD1/NOD2 signaling was independent of bacterial invasionin vitrobut required an intact T3SS-1. In the mouse colitis model, SipA triggered mucosal inflammation in wild-type mice but not in NOD1/NOD2-deficient mice. These findings implicate SipA-driven activation of the NOD1/NOD2 signaling pathway as a mechanism by which the T3SS-1 induces inflammatory responsesin vitroandin vivo.IMPORTANCESalmonella entericaserotype Typhimurium (S. Typhimurium) deploys a type III secretion system (T3SS-1) to induce intestinal inflammation and benefits from the ensuing host response, which enhances growth of the pathogen in the intestinal lumen. However, the mechanisms by which the T3SS-1 triggers inflammatory responses have not been resolved. Here we show that the T3SS-1 effector protein SipA induces NF-κB activation and intestinal inflammation by activating the NOD1/NOD2 signaling pathway. These data suggest that the T3SS-1 escalates innate responses through a SipA-mediated activation of pattern recognition receptors in the host cell cytosol.

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