Highest Number Of Virulence Genes Research Articles

Genomic analysis of Enterobacteriaceae from colorectal cancer patients at a tertiary hospital in Ghana: a case-control study.

Colorectal cancer (CRC) is a severe gastrointestinal cancer and a leading cause of cancer-related deaths in Ghana. The potential role of gut Enterobacteriaceae in the increasing incidence of CRC in Ghana is yet to be thoroughly investigated. In this study, Enterobacteriaceae from CRC patients and healthy control participants were analyzed by whole genome sequencing to identify genomic features that are associated with CRC. Socio-demographic data showed a significant association between age and alcohol consumption and CRC. Escherichia coli was the most abundant Enterobacteriaceae isolated from the study participants and they were predominantly intestinal commensals. Escherichia coli isolates belonging to phylogroup D encoded the highest number of virulence genes. The agn43 and int genes were widespread in Escherichia coli isolates from the CRC patients. Multilocus sequence types of potentially pathogenic Escherichia coli from the CRC patients also encoded genes involved in aggregation, adherence and biofilm formation. The ampC2 and ampH antimicrobial resistance genes were also widespread in the genome of the Escherichia coli isolates. This study highlights the virulence tendencies of Escherichia coli from CRC patients and their ability to transfer virulence determinants to other Enterobacteriaceae residing in the gut.

Multidrug-resistant Klebsiella pneumoniae and Klebsiella variicola isolated from patients in Portuguese hospitals: Genomic and phenotypic characterization

The emergence of antibiotic-resistant Klebsiella spp. has become a huge problem in clinical settings. In this study, we aimed to characterize the molecular and phenotypic features of 21 MDR Klebsiella isolates (n = 19 of K. pneumoniae, and n = 2 of K. variicola) isolated from patients admitted to two central hospitals in northern Portugal by using whole-genome sequencing (WGS), followed by an in vitro assessment of biofilm formation and in vivo evaluation of the pathogenicity in a Galleria mellonella larval model. Our findings showed a high prevalence of O1/O2 serotypes (14/21; 67 %) among the isolates tested, which is consistent with previous reports from Portugal. In contrast, a wide variety of K locus serotypes was found, where ST15-KL19 (4/21; 19 %) associated to serotype O1/O2v2 was the dominant one. Within the O1/O2v2 serotype, a ST10-KL151 Klebsiella variicola (strain H97) harboured a high number of virulence genes. We also found statistical differences in the ability to produce biofilm biomass within the strains, with a ST280-KL23 K. pneumoniae outcompeting nine other strains. According to our results, the most prominent serotype able to cause the death of G. mellonella was the KL105-O1/O2v2. Our findings emphasized the importance of the conducting continuous molecular surveillance in order to reveal the key molecular features to be considered in the development of novel strategies to treat Klebsiella spp.-associated infections.

Genomic diversity of Salmonella enterica isolated from raw chicken at retail establishments in Mexico

The genomic diversity of circulating non-typhoidal Salmonella in raw chicken was investigated in three states of central Mexico. A total of 192 S. enterica strains from chicken meat samples collected at supermarkets, fresh markets, and butcher shops were analyzed by whole-genome sequencing. The serovar distribution, occurrence of genes encoding for antimicrobial resistance, metal resistance, biocide resistance, plasmids and virulence factors, and clonal relatedness based on single nucleotide polymorphism (SNP) analysis were investigated. Serovars Infantis, Schwarzengrund and Enteritidis predominated among twenty identified. The distribution of serovars and proportion of AMR genes was different according to the state, year, season, and retail establishment (p < 0.001). Genes encoding metals resistance were identified in all the strains. A total of 145 virulence genes were identified and strains were classified into 32 virulotypes; serovars Infantis, Typhimurium, and Enteritidis showed the highest number of virulence genes. The strains matched 34 SNP clusters in the NCBI Pathogen Detection server and 59 %, which corresponded to Infantis, Schwarzengrund, Saintpaul, and Enteritidis, were associated with five major clusters and matched with chicken, environmental and clinical isolates from at least three countries. These results provide useful information to understand the epidemiology of Salmonella, conduct microbial risk assessment, and design risk-based control measures.

Characterization of the Virulency of Vibrio spp. in Giant Tiger Shrimp (Penaeus monodon) from Peninsular Malaysia

Nowadays, bacterial diseases caused by Vibrio spp. pose a significant obstacle to aquaculture growth, affecting socioeconomic development. The presence of pathogenic Vibrio spp. are gaining attention due to widespread mortality in fish and shellfish worldwide. This study investigates the distribution of virulence genes and their pathogenicity by experimentally infecting a healthy group of cultured shrimp, specifically Penaeus monodon. A total of 225 Vibrio spp. isolated from 210 cultured shrimp from various geographical regions in Peninsular Malaysia were examined, resulting in 13 Vibrio spp. being identified and characterized. According to virulence gene assessment, only eight of the 11 virulence genes were detected in the isolates, including chiA (89%), flaC (74%), tlh (72%), toxR (70%), luxR (40%), pirA (11%), pirB (11%), and hlyA (0.4%). Other virulence genes, such as tdh, trh, and ctxA, were not found in any of the isolates (0%). Then, three Vibrio isolates, including V. parahaemolyticus S12-3, V. campbellii S10-4, and V. rotiferianus S24-4, were selected for pathogenicity test based on highest number of virulence genes in each species. These species were subjected to immersion challenge test against postlarvae (PL) P. monodon approximately PL-20 with three different concentrations of 1 × 106, 1 × 107, and 1 × 108 CFU/mL. The V. parahaemolyticus S12-3 was determined to have lethal concentration 50 (LC50) 1 × 105 CFU/mL after 168 hr of exposure. The immersion challenge test resulted in a pale hepatopancreas and empty guts in P. monodon. Histopathological examination showed sloughing of epithelial cells in the hepatopancreatic tubule, hemocytic infiltration, massive vacuolation, and loss of hepatopancreatic tubule structure. Overall, the study demonstrated the virulence and pathogenicity of V. parahaemolyticus S12-3 toward P. monodon, which could be associated with its virulence properties. Furthermore, the current findings will be useful in developing microbiological risk assessments for shrimp farming and aquaculture management.

Short- and Long-Read Sequencing Reveals the Presence and Evolution of an IncF Plasmid Harboring blaCTX-M-15 and blaCTX-M-27 Genes in Escherichia coli ST131.

Escherichia coli sequence type 131 (ST131) has contributed to the spread of extended-spectrum beta-lactamase (ESBL) and has emerged as the dominant cause of hospital- and community-acquired urinary tract infections. Here, we report for the first time an in-depth analysis of whole-genome sequencing (WGS) of 4 ESBL-producing E. coli ST131 isolates recovered from patients in two hospitals in Armenia using Illumina short-read sequencing for accurate base calling to determine their genotype and to infer their phylogeny and using Oxford Nanopore Technologies long-read sequencing to resolve plasmid and chromosomal genetic elements. Genotypically, the four Armenian isolates were identified as part of the H30Rx/clade C2 (n = 2) and H41/clade A (n = 2) lineages and were phylogenetically closely related to isolates from the European Nucleotide Archive (ENA) database previously recovered from patients in the United States, Australia, and New Zealand. The Armenian isolates recovered in this study had chromosomal integration of the blaCTX-M-15 gene in the H30Rx isolates and a high number of virulence genes found in the H41 isolates associated with the carriage of a rare genomic island (in the context of E. coli ST131) containing the S fimbrial, salmochelin siderophore, and microcin H47 virulence genes. Furthermore, our data show the evolution of the IncF[2:A2:B20] plasmid harboring both blaCTX-M-15 and blaCTX-M-27 genes, derived from the recombination of genes from an IncF[F2:A-:B-] blaCTX-M-15-associated plasmid into the IncF[F1:A2:B20] blaCTX-M-27-associated plasmid backbone seen in two genetically closely related H41 Armenian isolates. IMPORTANCE Combining short and long reads from whole-genome sequencing analysis provided a genetic context for uncommon genes of clinical importance to better understand transmission and evolutionary features of ESBL-producing uropathogenic E. coli (UPEC) ST131 isolates recovered in Armenia. Using hybrid genome assembly in countries lacking genomic surveillance studies can inform us about new lineages not seen in other countries with genes encoding high virulence and antibiotic resistance harbored on mobile genetic elements.

Whole-Genome Sequencing Snapshot of Clinically Relevant Carbapenem-Resistant Gram-Negative Bacteria from Wastewater in Serbia

Wastewater (WW) is considered a source of antibiotic-resistant bacteria with clinical relevance and may, thus, be important for their dissemination into the environment, especially in countries with poor WW treatment. To obtain an overview of the occurrence and characteristics of carbapenem-resistant Gram-negative bacteria (CR-GNB) in WW of Belgrade, we investigated samples from the four main sewer outlets prior to effluent into international rivers, the Sava and the Danube. Thirty-four CR-GNB isolates were selected for antimicrobial susceptibility testing (AST) and whole-genome sequencing (WGS). AST revealed that all isolates were multidrug-resistant. WGS showed that they belonged to eight different species and 25 different sequence types (STs), seven of which were new. ST101 K. pneumoniae (blaCTX-M-15/blaOXA-48) with novel plasmid p101_srb was the most frequent isolate, detected at nearly all the sampling sites. The most frequent resistance genes to aminoglycosides, quinolones, trimethroprim-sulfamethoxazole, tetracycline and fosfomycin were aac(6')-Ib-cr (55.9%), oqxA (32.3%), dfrA14 (47.1%), sul1 (52.9%), tet(A) (23.5%) and fosA (50%), respectively. Acquired resistance to colistin via chromosomal-mediated mechanisms was detected in K. pneumoniae (mutations in mgrB and basRS) and P. aeruginosa (mutation in basRS), while a plasmid-mediated mechanism was confirmed in the E. cloacae complex (mcr-9.1 gene). The highest number of virulence genes (>300) was recorded in P. aeruginosa isolates. Further research is needed to systematically track the occurrence and distribution of these bacteria so as to mitigate their threat.

Genetic Diversity, Distribution, and Genomic Characterization of Antibiotic Resistance and Virulence of Clinical Pseudomonas aeruginosa Strains in Kenya.

Pseudomonas aeruginosa is a leading cause of nosocomial infections worldwide. It can produce a range of debilitating infections, have a propensity for developing antimicrobial resistance, and present with a variety of potent virulence factors. This study investigated the sequence types (ST), phenotypic antimicrobial susceptibility profiles, and resistance and virulence genes among clinical isolates from urinary tract and skin and soft tissue infections. Fifty-six P. aeruginosa clinical isolates were obtained from six medical centers across five counties in Kenya between 2015 and 2020. Whole-genome sequencing (WGS) was performed to conduct genomic characterization, sequence typing, and phylogenetic analysis of the isolates. Results showed the presence of globally distributed high-risk clones (ST244 and ST357), local high-risk clones (ST2025, ST455, and ST233), and a novel multidrug-resistant (MDR) clone carrying virulence genes (ST3674). Furthermore, 31% of the study isolates were found to be MDR with phenotypic resistance to a variety of antibiotics, including piperacillin (79%), ticarcillin-clavulanic acid (57%), meropenem (34%), levofloxacin (70%), and cefepime (32%). Several resistance genes were identified, including carbapenemases VIM-6 (ST1203) and NDM-1 (ST357), fluoroquinolone genes, crpP, and qnrVCi, while 14 and 22 different chromosomal mutations were detected in the gyrA and parC genes, respectively. All isolates contained at least three virulence genes. Among the virulence genes identified, phzB1 was the most abundant (50/56, 89%). About 21% (12/56) of the isolates had the exoU+/exoS- genotype, while 73% (41/56) of the isolates had the exoS+/exoU- genotype. This study also discovered 12 novel lineages of P. aeruginosa, of which one (ST3674) demonstrated both extensive antimicrobial resistance and the highest number of virulence genes (236/242, 98%). Although most high-risk clones were detected in Nairobi County, high-risk and clones of interest were found throughout the country, indicating the local spread of global epidemic clones and the emergence of new strains. Thus, this study illustrates the urgent need for coordinated local, regional, and international antimicrobial resistance surveillance efforts.

Application of a High-Throughput Targeted Sequence AmpliSeq Procedure to Assess the Presence and Variants of Virulence Genes in Salmonella.

We have developed a targeted, amplicon-based next-generation sequencing method to detect and analyze 227 virulence genes (VG) of Salmonella (AmpliSeqSalm_227VG) for assessing the pathogenicity potential of Salmonella. The procedure was developed using 80 reference genomes representing 75 epidemiologically-relevant serovars associated with human salmonellosis. We applied the AmpliSeqSalm_227VG assay to (a) 35 previously characterized field strains of Salmonella consisting of serovars commonly incriminated in foodborne illnesses and (b) 34 Salmonella strains with undisclosed serological or virulence attributes, and were able to divide Salmonella VGs into two groups: core VGs and variable VGs. The commonest serovars causing foodborne illnesses such as Enteritidis, Typhimurium, Heidelberg and Newport had a high number of VGs (217–227). In contrast, serovars of subspecies not commonly associated with human illnesses, such as houtenae, arizonae and salame, tended to have fewer VGs (177–195). Variable VGs were not only infrequent but, when present, displayed considerable sequence variation: safC, sseL, sseD, sseE, ssaK and stdB showed the highest variation and were linked to strain pathogenicity. In a chicken infection model, VGs belonging to rfb and sse operons showed differences and were linked with pathogenicity. The high-throughput, targeted NGS-based AmpliSeqSalm_227VG procedure provided previously unknown information about variation in select virulence genes that can now be applied to a much larger population of Salmonella for evaluating pathogenicity of various serovars of Salmonella and for risk assessment of foodborne salmonellosis.

IDENTIFICATION OF VIRULENCE FACTORS AMONG ESBL-PRODUCING ESCHERICHIA COLI CLINICAL ISOLATES FROM GAZA STRIP, PALESTINE

This study was done to assess the occurrence of virulence factors and correlation of phylogenetic grouping in ESBLs producing E. coli isolates from Palestine. Twenty-seven ESBLs producing E. coli isolates were collected between April and June 2013 from three hospitals in Gaza. Detection of genes encoding virulence factors, pathogenicity associated island marker (PAI) and phylogenetic groups were studied by PCR. The correlation of E. coli phylogenetic grouping with the virulence factors in the isolates was studied. The clonal relationships between the isolates were tested by pulsed-field gel electrophoresis (PFGE). Overall, 44.4% of the 27 E. coli isolates belonged to phylogroup B2, 44.4% to D and 11.2% to A. Among the isolates, fimH, traT and fimA were the most frequent virulence genes and were found over 85% of the isolates. PAIs was found in 8 isolates while the tcpC gene was detected in one isolate. The overall prevalence of PAI was higher in group B2 as compared to groups A and D (p&lt;0.043). A clonal diversity was confirmed among our isolates (27 unrelated PFGE profiles). We report for the first time the prevalence of tcpC as a new virulence marker and PAI in clinical ESBLs-producing E. coli in Palestine. This study indicates that most of the ESBL- positive isolates showed virulence genes and most strains belonged to phylogenetic groups B2 and D. The study suggested that high number of virulence genes in studied strains may be important factors in the infections development.

Whole genome sequencing snapshot of multi-drug resistant Klebsiella pneumoniae strains from hospitals and receiving wastewater treatment plants in Southern Romania.

We report on the genomic characterization of 47 multi-drug resistant, carbapenem resistant and ESBL-producing K. pneumoniae isolates from the influent (I) and effluent (E) of three wastewater treatment plants (WWTPs) and from Romanian hospital units which are discharging the wastewater in the sampled WWTPs. The K. pneumoniae whole genome sequences were analyzed for antibiotic resistance genes (ARGs), virulence genes and sequence types (STs) in order to compare their distribution in C, I and E samples. Both clinical and environmental samples harbored prevalent and widely distributed ESBL genes, i.e. blaSHV, blaOXA, blaTEM and blaCTX M. The most prevalent carbapenemase genes were blaNDM-1, blaOXA-48 and blaKPC-2. They were found in all types of isolates, while blaOXA-162, a rare blaOXA-48 variant, was found exclusively in water samples. A higher diversity of carbapenemases genes was seen in wastewater isolates. The aminoglycoside modifying enzymes (AME) genes found in all types of samples were aac(6’), ant(2'')Ia, aph(3'), aaD, aac(3) and aph(6). Quinolone resistance gene qnrS1 and the multi-drug resistance oqxA/B pump gene were found in all samples, while qnrD and qnrB were associated to aquatic isolates. The antiseptics resistance gene qacEdelta1 was found in all samples, while qacE was detected exclusively in the clinical ones. Trimethroprim-sulfamethoxazole (dfrA, sul1 and sul2), tetracyclines (tetA and tetD) and fosfomycin (fosA6, known to be located on a transpozon) resistance genes were found in all samples, while for choramphenicol and macrolides some ARGs were detected in all samples (catA1 and catB3 / mphA), while other (catA2, cmIA5 and aac(6’)Ib / mphE and msrE) only in wastewater samples. The rifampin resistance genes arr2 and 3 (both carried by class I integrons) were detected only in water samples. The highly prevalent ARGs preferentially associating with aquatic versus clinical samples could ascribe potential markers for the aquatic (blaSHV-145, qacEdelta1, sul1, aadA1, aadA2) and clinical (blaOXA-1, blaSHV-106,blaTEM-150, aac(3)Iia, dfrA14, oqxA10; oqxB17,catB3, tetD) reservoirs of AR. Moreover, some ARGs (oqxA10; blaSHV-145; blaSHV-100, aac(6')Il, aph(3')VI, armA, arr2, cmlA5, blaCMY-4, mphE, msrE, oqxB13, blaOXA-10) showing decreased prevalence in influent versus effluent wastewater samples could be used as markers for the efficiency of the WWTPs in eliminating AR bacteria and ARGs. The highest number of virulence genes (75) was recorded for the I samples, while for E and C samples it was reduced to half. The most prevalent belong to three functional groups: adherence (fim genes), iron acquisition (ent, fep, fyu, irp and ybt genes) and the secretion system (omp genes). However, none of the genes associated with hypervirulent K. pneumoniae have been found. A total of 14 STs were identified. The most prevalent clones were ST101, ST219 in clinical samples and ST258, ST395 in aquatic isolates. These STs were also the most frequently associated with integrons. ST45 and ST485 were exclusively associated with I samples, ST11, ST35, ST364 with E and ST1564 with C samples. The less frequent ST17 and ST307 aquatic isolates harbored blaOXA-162, which was co-expressed in our strains with blaCTX-M-15 and blaOXA-1.

Some pathogenic characters of paratyphoid Salmonella enterica strains isolated from poultry.

To investigate some pathogenic characters of Salmonella enterica strains isolated from poultry. Twenty-three genetically distinct Salmonella enterica strains, of different serovars and pulsotype, were examined for virulence traits. Resistance to gastric acid environment was estimated by measuring the percentage of survived bacterial cells after exposure for 2h to a synthetic gastric juice. Strains were analyzed with PCR for the presence of the following virulence genes: mgtC and rhuM located on SPI-3, sopB and pipB located on SPI-5, Salmonella virulence plasmid (spv) R (spvR), spvB and spvC located on Salmonella plasmid virulence and sodCI, sopE, and gipA located on prophage. Finally, resistance to 21 antibiotics was tested with Kirby-Bauer method. A percentage of 82.60% of strains were resistant to gastric environment after induction and 60.87% of the strains exhibited constitutive resistance too. Nineteen different virulence profiles were detected. The phage related genes sodCI and sopE and the plasmid mediated operon spvR, spvB and spvC (spvRBC) were detected in 82.60%, 47.82% and 52.17% of strains, respectively. Typhimurium and Enteritidis strains showed the highest number of virulence genes. Twenty-one different antibiotic resistance profiles were obtained and two isolates (Typhimurium and Enteritidis) resulted sensible to all the tested molecules. The ampicillin, streptomycin, sulfonamide and tetracycline resistance profile was detected in seven isolates (30.43%). Our results show that paratyphoid Salmonella strains with several characters of pathogenicity, that may be cause of severe pathology in animals and humans, are circulating among poultry.

Isolation and Identification of Arcobacter Species from Costa Rican Poultry Production and Retail Sources

Arcobacter is a gram-negative rod recognized as a potential food- and waterborne pathogen; nevertheless, little is known about the effects of this pathogen on human and animal health. Although Arcobacter species are commonly found in nature, poultry is suspected to be the main vehicle for the transmission of this pathogen. The aims of this work were to determine the prevalence of Arcobacter spp. in broilers produced in Costa Rica for human consumption and to analyze the pathogenic capacity of the isolates through the detection of virulence genes. One hundred fifty-two samples of cecal content (87 farms), 104 samples of carcass rinse after chiller (six processing plants), and 96 carcass rinses from as many retail stores were analyzed. The suspicious isolates were identified using genus-specific PCR, and species-level identification was achieved with a multiplex PCR. Virulence genes were identified using the protocol described by L. Douidah, L. de Zutter, J. Baré, P. De Vos, P. Vandamme, O. Vandenberg, A.-M. Van den Abeele, and K. Houf (J. Clin. Microbiol. 50:735-741, 2012), which includes nine different virulence genes. The overall isolation frequency of Arcobacter was 6.5% (n = 23). Eight (34.8%) of the isolates came from cecal content, 2 (8.7%) were isolated from samples taken after chiller, and 13 (56.5%) were from retail stores. The species isolated included A. thereius (30.4%), A. butzleri (21.7%), A. skirrowii (4.3%), and A. cibarius (4.3%). The remaining samples were classified as Arcobacter sp. Gene tlyA was the most prevalent virulence gene, present in 9 of 23 samples analyzed; genes hecA and pldA were present in one only strain each. A strain of A. butzleri isolated from a retail store presented the highest number of virulence genes (five), and 11 samples did not present any of the genes analyzed. The results obtained suggest that the presence of virulent Arcobacter isolates in the poultry production chain from Costa Rica could be a risk for individuals who consume the contaminated product.

Assessing the population dynamics of Escherichia coli in a metropolitan river after an extreme flood event.

We investigated Escherichia coli populations in a metropolitan river after an extreme flood event. Between nine and 15 of the 23 selected sites along the river were sampled fortnightly over three rounds. In all, 307 E. coli were typed using the PhP typing method and were grouped into common (C) or single (S) biochemical phenotypes (BPTs). A representative from each of the 31 identified C-BPTs was tested for 58 virulence genes (VGs) associated with intestinal and extra-intestinal E. coli, resistance to 22 antibiotics, production of biofilm and cytotoxicity to Vero cells. The number of E. coli in the first sampling round was significantly (P < 0.01) higher than subsequent rounds, whereas the number of VGs was significantly (P < 0.05) higher in isolates from the last sampling round when compared to previous rounds. Comparison of the C-BPTs with an existing database from wastewater treatment plants (WWTPs) in the same catchment showed that 40.6% of the river isolates were identical to the WWTP isolates. The relatively high number of VGs and antibiotic resistance among the C-BPTs suggests possessing and retaining these genes may provide niche advantages for those naturalised and/or persistent E. coli populations which may pose a health risk to the community.

The spread of KPC-producing Enterobacteriaceae in Spain: WGS analysis of the emerging high-risk clones of Klebsiella pneumoniae ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3.

We analysed the microbiological traits and population structure of KPC-producing Enterobacteriaceae isolates collected in Spain between 2012 and 2014. We also performed a comparative WGS analysis of the three major KPC-producing Klebsiella pneumoniae clones detected. Carbapenemase and ESBL genes were sequenced. The Institut Pasteur MLST scheme was used. WGS data were used to construct phylogenetic trees, to identify the determinants of resistance and to de novo assemble the genome of one representative isolate of each of the three major K. pneumoniae clones. Of the 2443 carbapenemase-producing Enterobacteriaceae isolates identified during the study period, 111 (4.5%) produced KPC. Of these, 81 (73.0%) were K. pneumoniae and 13 (11.7%) were Enterobacter cloacae. Three major epidemic clones of K. pneumoniae were identified: ST11/KPC-2, ST101/KPC-2 and ST512/KPC-3. ST11/KPC-2 differed from ST101/KPC-2 and ST512/KPC-3 by 27 819 and 6924 SNPs, respectively. ST101/KPC-2 differed from ST512/KPC-3 by 28 345 SNPs. Nine acquired resistance genes were found in ST11/KPC-2, 11 in ST512/KPC-3 and 13 in ST101/KPC-2. ST101/KPC-2 had the highest number of virulence genes (20). An 11 bp deletion at the end of the mgrB sequence was the cause of colistin resistance in ST512/KPC-3. KPC-producing Enterobacteriaceae are increasing in Spain. Most KPC-producing K. pneumoniae isolates belonged to only five clones: ST11 and ST512 caused interregional spread, ST101 caused regional spread and ST1961 and ST678 produced independent hospital outbreaks. ST101/KPC-2 had the highest number of resistance and virulence genes. ST101/KPC-2 and ST512/KPC-3 were recently implicated in the spread of KPC in Italy.

Multilocus Sequence Typing and Virulence Profiles in Uropathogenic Escherichia coli Isolated from Cats in the United States.

The population structure, virulence, and antimicrobial resistance of uropathogenic E. coli (UPEC) from cats are rarely characterized. The aim of this study was to compare and characterize the UPEC isolated from cats in four geographic regions of USA in terms of their multilocus sequence typing (MLST), virulence profiles, clinical signs, antimicrobial resistance and phylogenetic grouping. The results showed that a total of 74 E. coli isolates were typed to 40 sequence types with 10 being novel. The most frequent phylogenetic group was B2 (n = 57). The most frequent sequence types were ST73 (n = 12) and ST83 (n = 6), ST73 was represented by four multidrug resistant (MDR) and eight non-multidrug resistant (SDR) isolates, and ST83 were significantly more likely to exhibit no drug resistant (NDR) isolates carrying the highest number of virulence genes. Additionally, MDR isolates were more diverse, and followed by SDR and NDR isolates in regards to the distribution of the STs. afa/draBC was the most prevalent among the 29 virulence-associated genes. Linking virulence profile and antimicrobial resistance, the majority of virulence-associated genes tested were more prevalent in NDR isolates, and followed by SDR and MDR isolates. Twenty (50%) MLST types in this study have previously been associated with human isolates, suggesting that these STs are potentially zoonotic. Our data enhanced the understanding of E. coli population structure and virulence association from cats. The diverse and various combinations of virulence-associated genes implied that the infection control may be challenging.

Análisis genético y propiedades virulentas de cepas de Escherichia coliaisladas desde infección vaginal

Escherichia coliis able to produce different infections in humans. It pathogenicity in the female genital tract is unknown. To determine the presence of virulence genes (VG) in E. colistrains isolated from the female genital tract. 146 E. colistrains isolated as monomicrobial cultures from vaginal infections were genetically characterized by search of hly, iucC, afa, fimH, neuC, sfa/foc, cnF1, papC, usp,and ibeAVG. Studies were performed by means PFGE and PCR. Genetic analysis of the strains showed two groups with a similarity of approximately 80%. The similarity genetic intragroup was approximately 95%. The results showed strains with a high number of VG and the most common were cnf1andfimH.The afagene was not detected. Were identified eight VG combinations and the most common was papC+ hly+ iucC+ afa- neuC- fimH+ sfa/foc+ cnf1+ usp+ ibeA-. The studied strains are concentrated in two genetic groups. Most of the strains contain a great number of VG present in E. coliisolated from extraintestinal infections. It is important to develop new research strategies in this area, to deepen the phylogenetic knowledge of these strains and confirm their true role in vaginal infection.

High diversity of Staphylococcus aureus and Staphylococcus pseudintermedius lineages and toxigenic traits in healthy pet-owning household members. Underestimating normal household contact?

Forty-three unrelated pet-owning households were screened in Spain to study the Staphylococcus aureus and Staphylococcus pseudintermedius nasal carriage, their genetic lineages and virulence traits. Sixty-seven healthy owners and 66 healthy pets were investigated. Isolates characterization was performed and potential interspecies transmission was assessed. S. aureus was present in 51.2% of households studied while S. pseudintermedius in 30.2%. Twenty-eight owners (41.8%) carried S. aureus: one methicillin-resistant S. aureus (MRSA) [t5173-ST8-SCCmecIVa] and 27 methicillin-susceptible S. aureus (MSSA). Three owners (4.5%) were colonized by methicillin-susceptible S. pseudintermedius (MSSP). Fifteen pets (22.7%) carried S. pseudintermedius: two methicillin-resistant S. pseudintermedius (MRSP) [ST71-SCCmecII/III; ST92-SCCmecV] and 13 MSSP; in addition, 8 pets (12.1%) presented MSSA. High diversity of spa and sequence types (STs) was detected. Typical livestock-associated S. aureus lineages (CC398, CC9) were observed in humans and/or companion animals and hospital and/or community-acquired S. aureus lineages (CC45, CC121, CC5, CC8) were detected among pets. Almost 40% of S. pseudintermedius were multidrug-resistant. S. aureus isolates harboured a remarkable high number of virulence genes. The expA gene was detected in 3 S. pseudintermedius isolates. Identical strains from both owners and their pets were identified in 5 households (11.6%): (a) four MSSA (t073-ST45/CC45, t159-ST121/CC121, t209-ST109/CC9, t021-ST1654([new])/singleton) and (b) one multidrug-resistant MSSP (ST142([new])). Highly clonally diverse and toxigenic S. aureus and S. pseudintermedius are common colonizers of healthy humans and pets. The presence of these bacterial species, virulence genes, and interspecies transmission detected, points out to consider pet ownership as a risk factor to acquire, maintain and spread, potential pathogenic bacteria.

Genes de virulencia y bacteriocinas en cepas de Enterococcus faecalis aisladas desde diferentes muestras clínicas en la Región del Maule, Chile

The presence of virulence genes (VG) and bacteriocins from different clinical samples was studied in Enterococcus faecalis isolated from urinary tract infections (UTI), bacteremia and endodontitis and was correlated with haemolysin and gelatinase activity. We evaluated the presence of VG by PCR in 150 strains of E. faecalis including cylA, aggA, efaA, eep, gelE, esp, as-48, bac31, entL50A/B, entA, entP, entB, enlA andentl071. Haemolysin and gelatinase activity was studied. gelE and cylA genes expressed hemolysin and gelatinase, respectively. This activity was observed in some strains of bacteremia, UTI and endodontitis. The highest number of VG was detected in bacteremic strains, being aggA and entA genes the most frequent. efaA, esp, entA, entL50A/B were associated with their clinical origin (p < 0.05). The most common genetic profile was aggA-eep-enlA-entL50A/B. E. faecalis from UTI, bacteremia and endodontitis presented different gene combinations. Some of the genes studied were related to their clinical origin. The results obtained in this study are similar to those reported in other countries.

Molecular Characterization of Escherichia coli Strains That Cause Symptomatic and Asymptomatic Urinary Tract Infections

The differences between Escherichia coli strains associated with symptomatic and asymptomatic urinary tract infections (UTIs) remain to be properly determined. Here we examined the prevalence of plasmid types and bacteriocins, as well as genetic relatedness, in a defined collection of E. coli strains that cause UTIs. Comparative analysis identified a subgroup of strains with a high number of virulence genes (VGs) and microcins M/H47. We also identified associations between microcin genes, VGs, and specific plasmid types.

Population structure, virulence potential and antibiotic susceptibility of uropathogenic Escherichia coli from Northwest England

Multilocus sequence typing (MLST) has been used to characterize diverse pathogens, including uropathogenic Escherichia coli (UPEC). There has been significant interest in the contribution of the O25b:H4-ST131 lineage to UPEC disease, as these isolates are often highly virulent and exhibit multidrug resistance. To reveal the wider impact of sequence type (ST) 131, we have examined its contribution to the overall population structure of UPEC isolates that were not selected on the basis of virulence or antibiotic resistance. Three hundred UPEC isolates were recovered from community and hospital urine samples examined by clinical microbiology laboratories in the Northwest region of England in June 2007 and June 2009. They were characterized by susceptibility profiling, MLST and virulence gene PCR. PFGE was used to examine isolates from key clones. The most common lineage was ST73 (16.6%) followed by ST131 (13.3%), ST69 (9%), ST95 (6.3%), ST10 (4.3%) and ST127 (3.6%). ST131 isolates were significantly more likely to exhibit high levels of antibiotic resistance (35% being CTX-M-15 PCR positive) and those of ST127 were the most widely susceptible but carried the highest number of virulence genes. Only when the CTX-M-15-O25b-positive strains were examined was a high level of virulence observed for ST131 isolates. PFGE indicated ongoing local evolution in ST131. ST131 isolates are well established in the wider UPEC population. This clone is still evolving and we further support suggestions that it represents a real threat to health. We suggest that ST127 is a recently emerged, community-associated, virulent clone that warrants further study.