Enterobacterial Repetitive Intergenic Consensus-polymerase Chain Research Articles

Spread of multidrug-resistant Escherichia coli within domestic aggregates (humans, pets, and household environment)

Abstract Advances in veterinary medicine have been associated with recourse to antimicrobial therapies, which favors the emergence of resistant bacteria, potentially able to spread globally. The aim of the present study was to elucidate the manner in which shared environments between pets receiving antimicrobial treatments and their owners could contribute to the spread of antimicrobial drug-resistant Escherichia coli . Three domestic aggregates, including pets, owners, and household environment were studied. Each core pet had a history of previous antimicrobial therapies. Overall, 231 E. coli isolates were recovered from pets' feces, urine, oral secretion, skin, and fur; and owners' hands and stool swabs. Commonly touched household objects and surfaces (light switches, door knobs, TV remote control, mobile phones, banister, refrigerator door handle, kitchen floor, pet beds, leash, food, and water recipients) were also sampled. All strains were analyzed by antimicrobial susceptibility testing. Subsequently, some isolates were selected for Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction and Pulsed-Field Gel Electrophoresis analyses, to evaluate their genetic relatedness. Antimicrobial susceptibility tests displayed 20 different phenotypic patterns with an important representation of multidrug-resistant ones (75.0%). The 3 core dogs presented multidrug-resistant E. coli clones disseminated over various body sites. In 2 of 3 domestic aggregates, A and B, clonal disseminations among animals, owners, and household surfaces were also observed. Results confirmed the dissemination of multidrug-resistant E. coli within and through the household environment, highlighting the relevance of pets in the community spread of antimicrobial resistance.

Whole Genome Sequencing in Real-Time Investigation and Management of a Pseudomonas aeruginosa Outbreak on a Neonatal Intensive Care Unit.

To use whole genome sequencing to describe the likely origin of an outbreak of Pseudomonas aeruginosa in a neonatal unit. Outbreak investigation. The neonatal intensive care unit service of a major obstetric tertiary referral center. Infants admitted to the neonatal unit who developed P. aeruginosa colonization or infection. We undertook whole genome sequencing of P. aeruginosa strains isolated from colonized infants and from the neonatal unit environment. Eighteen infants were colonized with P. aeruginosa. Isolates from 12 infants and 7 environmental samples were sequenced. All but one of the clinical isolates clustered in ST253 and no differences were detected between unmapped reads. The environmental isolates revealed a variety of sequence types, indicating a large diverse bioburden within the unit, which was subsequently confirmed via enterobacterial repetitive intergenic consensus-polymerase chain reaction typing of post-outbreak isolates. One environmental isolate, obtained from a sink in the unit, clustered within ST253 and differed from the outbreak strain by 9 single-nucleotide polymorphisms only. This information allowed us to focus infection control activities on this sink. Whole genome sequencing can provide detailed information in a clinically relevant time frame to aid management of outbreaks in critical patient management areas. The superior discriminatory power of this method makes it a powerful tool in infection control.

Enterococcus faecalis with capsule polysaccharides type 2 and biofilm-forming capacity in Indonesians requiring endodontic treatment.

The aim of the present study was to evaluate the genetic diversity of Enterococcus faecalis (E. faecalis) strains isolated from saliva and infected root canal samples from Indonesians requiring endodontic treatment. A total of 50 isolates were genotyped using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and analyzed for locus polymorphisms of their capsule polysaccharides (CPS) and for biofilm-forming capabilities. It was shown that all E. faecalis isolates shared >60% similarity. A higher degree of diversity of E. faecalis was observed in cluster 1 (C1, 28%) and cluster 2 (C2, 22%) from samples isolated from infected root canals. CPS type 2 was the dominant form observed in five clusters (C1-C5), but there was no relationship between the origins of these isolates. In contrast, all isolates in cluster C5 were of root canal origin, and 50% were associated with a strong biofilm phenotype. Five unclustered strains were saliva isolates (<60% similarity). Most of these strains showed weak biofilm capability. E. faecalis CPS type 2 is relatively common in Indonesians requiring endodontic treatment, and there are differences in the biofilm-forming abilities produced by CPS type 2 strains in all isolates depending on the source. In addition, there is no relationship between the ERIC-PCR profile and biofilm formation.

Phenotypic characterization and ERIC–PCR based genotyping of Paenibacillus larvae isolates recovered from American foulbrood outbreaks in honey bees from Italy

Background: Paenibacillus larvae is the etiological agent of American foulbrood (AFB), a widespread and severe bacterial brood disease of honey bees. The genomic characterization of P. larvae strains by enterobacterial repetitive intergenic consensus–polymerase chain reaction (ERIC–PCR) is able to differentiate four genotypes (ERIC I, ERIC II, ERIC III, ERIC IV). The information on the presence of P. larvae ERIC genotypes worldwide is few.Objectives: We have characterized P. larvae strains isolated in Italy from AFB outbreaks to obtain information on ERIC genotypes and phenotypes of the strains circulating in the country.Methods: A total of 117 P. larvae isolates from 115 AFB outbreaks occurring in 2008–2012 were subjected to phenotypic and genetic characterization.Results: The genomic characterization allowed the identification of ERIC I and ERIC II genotypes. Examining the data of Northern and Central Italy separately it was noted that in Northern Italy most outbreaks were caused by the ERIC I genotype (78.6%), followed by the ERIC II genotype (18.6%) and by co-infections (ERIC I + ERIC II) (2.6%). In Central Italy, only outbreaks caused by the ERIC I genotype were observed. With regard to phenotypic characteristics all examined strains of ERIC II genotype fermented fructose while no strains of ERIC I genotype possessed this ability.Conclusion: Both P. larvae ERIC I and ERIC II genotypes were isolated from the AFB outbreaks, but ERIC II genotype was isolated only in Northern Italy. The fermentation of fructose seems to be a genotype-specific biochemical marker.

Presence of fimH, mrkD, and irp2 virulence genes in KPC-2-producing Klebsiella pneumoniae isolates in Recife-PE, Brazil.

Klebsiella pneumoniae strains can produce different virulence factors, such as fimbrial adhesins and siderophores, which are important in the colonization and development of the infection. The aims of this study were to determine the occurrence of fimH, mrkD, and irp2 virulence genes in 22 KPC-2-producing K. pneumoniae isolates as well as 22 not producing-KPC isolates, from patients from different hospitals in Recife-PE, Brazil, and also to analyze the clonal relationship of the isolates by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The genes were detected by PCR and DNA sequencing. The bla KPC-2 gene was identified in 22 KPC-positive isolates. On analyzing the antimicrobial susceptibility profile of the isolates, it was detected that polymyxin and amikacin were the antimicrobials of best activity against K. pneumoniae. On the other hand, five isolates exhibited resistance to polymyxin. In the KPC-positive group, was observed a high rate of resistance to cephalosporins, followed by carbapenems. Molecular typing by ERIC-PCR detected 38 genetic profiles, demonstrating a multiclonal spread of the isolates analyzed. It was observed that the virulence genes irp2, mrkD, and fimH were seen to have together a higher frequency in the KPC-positive group. The accumulation of virulence genes of KPC-positive K. pneumoniae isolates, observed in this study, along with the multi-resistance impose significant therapeutic limitations on the treatment of infections caused by K. pneumoniae.

Genetic heterogeneity of Escherichia coli isolated from pasteurized milk in State of Paraná, Brazil

Food contamination caused by enteric pathogens is a major cause of diarrheal disease worldwide, resulting in high morbidity and mortality and significant economic losses. Bacteria are important agents of foodborne diseases, particularly diarrheagenic Escherichia coli. The present study assessed the genetic diversity and antimicrobial resistance of E. coli isolates from pasteurized milk processed in 21 dairies in northwestern State of Parana, Brazil. The 95 E. coli isolates were subjected to antimicrobial susceptibility testing according to the recommendations of the Clinical and Laboratory Standards Institute and assessed genotypically by Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR). The highest rate of resistance was observed for cephalothin (55.78%). ERIC-PCR revealed high genetic diversity, clustering the 95 bacterial isolates into 90 different genotypic patterns. These results showed a heterogeneous population of E. coli in milk samples produced in the northwestern region of Paraná and the need for good manufacturing practices throughout the processing of pasteurized milk to reduce the risk of foodborne illnesses.

Effect of land application of manure from enrofloxacin-treated chickens on ciprofloxacin resistance of Enterobacteriaceae in soil

A field plot experiment was carried out to evaluate the impact of spreading chicken manure containing enrofloxacin (ENR) and its metabolite ciprofloxacin (CIP), on the levels of CIP-resistant Enterobacteriaceae in soil. The manures from chickens treated with ENR and from untreated control chickens were applied on six plots. Total and CIP-resistant Enterobacteriaceae were counted on Violet Red Bile Glucose medium containing 0 to 16mgL−1 of CIP. A total of 145 isolates were genotyped by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The minimum inhibitory concentration (MIC) of CIP for the isolates of each ERIC-PCR profile was determined. The most frequently isolated Enterobacteriaceae included Escherichia coli, and to a lesser extent, Enterobacter and 5 other genera from environmental origin. The composition of the E. coli community differed between manure and manured soil suggesting that the E. coli genotypes determined by ERIC-PCR varied significantly in their ability to survive in soil. One of these genotypes, including both susceptible and resistant isolates, was detected up to 89days after the manure was applied. Most of the E. coli isolated in soil amended with manure from treated chickens was resistant to CIP (with a MIC ranging between 2 and 32mgL−1). In contrast, despite the presence of ENR in soil at concentrations ranging from 13–518μgkg−1, the environmental Enterobacteriaceae isolates had a CIP MIC≤0.064mgL−1, except one isolate which had a MIC of 0.25mgL−1, These results showed that spreading manure from ENR-treated chickens enabled CIP-resistant E. coli to persist for at least three months in the soil. However, neither the presence of fluoroquinolones, nor the persistence of CIP-resistant E. coli, increased the CIP-susceptibility of environmental Enterobacteriaceae.

Characterization ofSalmonellaEnteritidis strains isolated from poultry and farm environments in Brazil

Salmonella Enteritidis is a major causative agent of foodborne outbreaks worldwide. Using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and pulsed-field gel electrophoresis (PFGE), this study assessed the genetic relatedness, the pathogenic potential, and antimicrobial resistance in 60 strains isolated from chickens and the farm environment in Brazil between 2004 and 2010. The resulting concatenated dendrogram of the two methodologies distinguished the strains into two clusters. Some strains isolated from the two sources were indistinguishable. All the strains contained the 13 virulence markers investigated. Forty-four strains were resistant to nalidixic acid. Quinolone resistance presented by many strains suggests that quinolones may have been used to treat chickens. The high prevalence of virulence markers highlights the importance of poultry as vehicles of S. Enteritidis strains that have the potential to cause disease.

Comparative study of different molecular methods for typing of Acinetobacter baumannii clinical isolates from University Hospitals

Acinetobacter baumannii, a rod-shape Gram-negative bacterium, is an opportunistic pathogen causing diseases in humans. This bacterium has been recognized as one of the leading causes of nosocomial infection which occurs in hospital or hospital-like setting. The antibiotic resistance of A. baumannii could result from the heavy use of antibiotics and has been recognized as a threat to human health. However, prevention against the disease caused by A. baumannii is difficult due to variable host susceptibility against their infections. We isolated 53 bacterial strains from four different university hospitals in South Korea and identified 34 out of the 53 isolates as A. baumannii, based on the nucleotide sequence of 16S rRNA and gpi genes. For the subtyping of the clinical isolates, we used enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and multilocus sequencing typing (MLST) and compared the results. The result of ERIC-PCR showed that there are 14 distinct DNA fingerprint patterns in the 34 A. baumannii clinical isolates. For MLST analysis of the isolates, we amplified and sequenced seven housekeeping genes (gltA, gyrB, gdhB, recA, cpn60, gpi, and rpoD) from each isolate. Each unique allelic profile at the concatenated nucleotide sequences of the seven genes was assigned as a sequence type (ST) and six different STs (ST92, ST105, ST138, ST169, ST262, and ST357) were detected in the 34 A. baumannii clinical isolates. Among the six STs, ST138 was the most ubiquitous in the A. baumannii clinical isolates. To examine the regional distribution of the isolates, STs were clustered into clonal complexes based on their similarity to a previously registered central genotype and the clustering was verified by network phylogenetic analysis.

Klebsiella pneumoniae from Indonesian Tempeh were Genetically Different from that of Pathogenic Isolates

Tempeh is important traditional Indonesian fermented food made from soybeans employing Rhizopus oligosporus or R. microsporus . During the process of tempeh production, some bacteria from the environment and tempeh starter become an integral part of tempeh, and even have important roles in determining the final quality of tempeh it self. Several studies reported the presence of Klebsiella pneumoniae in tempeh as one of vitamin B12 producing bacteria in tempeh. However, K. pneumoniae also known as opportunistic pathogens causing pneumonia and liver abscess in human. In this study, Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) was employed to determine genetic diversity of K. pneumoniae isolated from tempeh and compared them with medical isolates. The result indicated that isolates from tempeh were genetically distinct from those of medical isolates.

Gut microbial diversity in rat model induced by rhubarb.

Rhubarb is often used to establish chronic diarrhea and spleen (Pi)-deficiency syndrome animal models in China. In this study, we utilized the enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) method to detect changes in bacterial diversity in feces and the bowel mucosa associated with this model. Total microbial genomic DNA from the small bowel (duodenum, jejunum, and ileum), large bowel (proximal colon, distal colon, and rectum), cecum, and feces of normal and rhubarb-exposed rats were used as templates for the ERIC-PCR analysis. We found that the fecal microbial composition did not correspond to the bowel bacteria mix. More bacterial diversity was observed in the ileum of rhubarb-exposed rats (P<0.05). Furthermore, a 380 bp product was found to be increased in rhubarb-exposed rats both in faces and the bowel mucosa. The product was cloned and sequenced and showed high similarity with regions of the Bacteroides genome. AS a result of discriminant analysis with the SPSS software, the Canonical Discriminant Function Formulae for model rats was established.

Genetic Diversity of Klebsiella spp. Isolated from Tempe based on Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR)

Tempe is an Indonesian fermented food prepared by fermenting dehulled cooked soybeans with Rhizopus oligosporus. Many types of bacteria are also involved during tempe fermentation, and one of these is Klebsiella spp. Some isolates of K. pneumoniae produces vitamin B12 in tempe but it has also been classified as an opportunistic pathogen. For this reason Klebsiella spp. in tempe is important to be studied. The aim of this study was to investigate the genetic diversity of Klebsiella spp. from tempe employing ERIC-PCR method. Sixty-one isolates of Klebsiella have been isolated from sixteen tempe producers in Bogor, Jakarta, Malang, Tengerang, Bandung and Cianjur. 63F and 1387R primers were used to amplify 16S rDNA sequences, and 1R and 1F primers were used for ERIC analysis. The results of this research showed that sixty-one strains of Klebsiella were clustered into 17 groups. Based on ERIC-PCR analysis, isolates of Klebsiella could be grouped into different profiles which some of these groups consisted of isolates with identical ERIC-PCR profiles. Several identical ERIC-PCR profiles were found in tempe from the same producer. There was no correlation observed between genetic similarity among isolates with the origin of tempe.

Enterobacterial repetitive intergenic consensus-polymerase chain reaction typing of Escherichia coli isolated from hospitalized neonates

Objective To explore the genetic relationship among the isolates of Escherichia coli, and to analyze the epidemiological status. Methods One hundred and ten strains of Escherichia coli were isolated from 102 hospitalized neonates in the Neonatal Center of Beijing Children's Hospital. The homologous relation among the strains were typed and studied by using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) method. Results One hundred and two cases of neonates were selected, including 61 male cases and 41 female cases. Among them, 94 cases were full-term infants, 8 cases were preterm infants, 25 cases≤7 days, and 77 cases>7 days. One hundred and ten strains of Escherichia coli isolated clinically by ERIC-PCR typing were divided into 58 types, fingerprints indnded 4-12 bands, and the similarity coefficient was between 26.2% and 100.0%. The dominant genotype contained 6 strains, with 4-5 bands, and the similarity coefficient was 88.9%-100.0%. In dominant genotype E58, 5 out of 6 strains were attacked in March, and 1 strain attacked by the end of February. In the second dominant type E32, 4 out of 5 strains were spread in May, and 1 strain in July. In E23 type, 4 out of 5 strains were distributed in September, and 1 strain in October. There were 8 pairs of clinical isolates from 8 neonatal patients, including 7 pairs of them belonging to the same genotype, and the other 1 pair of isolates did not belong to the same genotype and was distantly related. From homology analysis point of view, the possibility of the different isolates was infectious or contaminant. Two strains were isolated from the blood and cerebrospinal fluid of the same patient, belonging to the same genotype, with 100.0% similarity coefficient. Five isolates were confirmed to have closer relationship by ERIC-PCR genotyping. One isolate derived from a child and the other 4 isolates derived from the other 4 children were considered hospital-acquired infection since these five children shared one ward. Conclusions Escherichia coli infections in full-term infants are more common. Most of them are late infections, and boys are more than girls. Different seasons may have different types of epidemic caused by Escherichia coli infection of respiratory tract. Strains of high homology hospital-acquired infection by Escherichia coli was found at Beijng Children's Hospital had Escherichia coli hospital-acquired infection. ERIC-PCR typing method can track the source of infection, which plays a role in prevention and control of nosocomial infection. Key words: Escherichia coli; Enterobacterial repetitive intergenic consensus; Polymerase chain reaction; Infant, newborn

Prevalence and characterization of Listeria monocytogenes isolated from retail-level ready-to-eat foods in South China

Listeria monocytogenes is an important food-borne pathogen causing meningitis, meningoencephalitis and abortion. To assess the potential risk to consumer health, the presence of L. monocytogenes was investigated using qualitative and quantitative methods. Ten (6.33%) of 158 retail RTE food samples were positive for L. monocytogenes and the contamination levels were less than 10 MPN/g,while none of 65 dairy products was positive for L. monocytogenes. The 37 strains were grouped into five clusters and two singletons, five clusters and two singletons, and three clusters and one singleton by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and RAPD fingerprint respectively, at similarity coefficient of 80%. The susceptibility test showed that 83.8% were susceptible to 15 antimicrobials; two were penicillin-resistant, and one was multidrug-resistant to kanamycin, tetracycline, sulfamethoxazole, rifampin, gentamycin, penicillin, and ampicillin. Virulent L. monocytogenes that possess partial antimicrobial resistance, and serotypes frequently associated with listeriosis were recovered from RTE foods. Consumers may, therefore, be exposed to potential risks of L. monocytogenes infection in South China. This study contributed to the prevalence and contamination levels of L. monocytogenes in RTE foods in South China for the first time, providing baseline information for Chinese regulatory authorities to formulate a regulatory framework for controlling L. monocytogenes to improve the microbiological safety of RTE foods.

Antibiotic resistance and molecular typing among cockle (Anadara granosa) strains of Vibrio parahaemolyticus by polymerase chain reaction (PCR)-based analysis

Genomic DNA of Vibrio parahaemolyticus were characterized by antibiotic resistance, enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) analysis. These isolates originated from 3 distantly locations of Selangor, Negeri Sembilan and Melaka (East coastal areas), Malaysia. A total of 44 (n = 44) of tentatively V. parahaemolyticus were also examined for the presence of toxR, tdh and trh gene. Of 44 isolates, 37 were positive towards toxR gene; while, none were positive to tdh and trh gene. Antibiotic resistance analysis showed the V. parahaemolyticus isolates were highly resistant to bacitracin (92%, 34/37) and penicillin (89%, 33/37) followed by resistance towards ampicillin (68%, 25/37), cefuroxime (38%, 14/37), amikacin (6%, 2/37) and ceftazidime (14%, 5/37). None of the V. parahaemolyticus isolates were resistant towards chloramphenicol, ciprofloxacin, ceftriaxone, enrofloxacin, norfloxacin, streptomycin and vancomycin. Antibiogram patterns exhibited, 9 patterns and phenotypically less heterogenous when compared to PCR-based techniques using ERIC- and RAPD-PCR. The results of the ERIC- and RAPD-PCR were analyzed using GelCompare software. ERIC-PCR with primers ERIC1R and ERIC2 discriminated the V. parahaemolyticus isolates into 6 clusters and 21 single isolates at a similarity level of 80%. While, RAPD-PCR with primer Gen8 discriminated the V. parahaemolyticus isolates into 11 clusters and 10 single isolates and Gen9 into 8 clusters and 16 single isolates at the same similarity level examined. Results in the presence study demonstrated combination of phenotypically and genotypically methods show a wide heterogeneity among cockle isolates of V. parahaemolyticus.

Class 1 Integrons in Urinary Isolates of Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae in Southern China During the Past Five Years

We analyzed extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (226) and Klebsiella pneumoniae (53) collected from urine specimens during 2005-2009 for the presence of ESBL genes, class 1 integrons, and characterization of gene cassettes. TEM and CTX-M β-lactamase genes were the most prevalent. One hundred and forty-four E. coli and 35 K. pneumoniae were positive for the class 1 integrase gene; among them, 99 E. coli and 14 K. pneumoniae detected gene cassettes. Gene cassette regions were identified by restriction fragment length polymorphism and DNA sequencing analysis. Eleven distinct gene cassette arrays were found in E. coli isolates, and seven distinct gene cassette arrays were found in K. pneumoniae isolates. The cassette array aacA4-catB8-aadA1 was first found in E. coli and dfrA1-orfC was first reported in K. pneumoniae. Most of the gene cassettes found in this class 1 integrons were for aminoglycoside resistance. Enterobacterial repetitive intergenic consensus-polymerase chain reaction fingerprint patterns revealed the isolates carrying gene cassettes were genetically unrelated. In conclusion, we studied the class 1 integrons among urinary isolates of ESBL-producing E. coli and K. pneumoniae in Southern China during the past 5 years and found that class 1 integrons were widely disseminated and played a major role in antibiotic resistance.

Pseudomonas aeruginosa infection among cystic fibrosis and ICU patients in the referral children medical hospital in Tehran, Iran.

Pseudomonas aeruginosa is one of the important causes of hospital-acquired infections in Intensive Care Unit (ICU) and considered as a major determinant of morbidity and mortality in patients affected by cystic fibrosis (CF). The aim of this study was to investigate clonal diversity among randomly picked P. aeruginosa isolates of CF and the other hospitalized patients in ICU. Cultivation, identification, and antimicrobial susceptibility testing of P. aeruginosa isolates were performed using standard techniques. The genetic similarity of the strains was investigated by amplification of the Enterobacterial Repetitive Intergenic Consensus-polymerase chain reaction (ERIC-PCR) sequence. Among 49 isolates, sixteen were isolated from 11 patients affected by CF and 33 came from an epidemiological investigation of 25 P. aeruginosa infected patients of ICU. Five clusters were generated for all isolates analyzed through ERIC-PCR genotyping. Two major clusters (B and C) were discovered in P. aeruginosa isolates of ICU and CF patients during the whole period of this study. Fifteen unique antibiogram patterns obtained from all isolates and multi-resistant P. aeruginosa (MRPA) were identified in 23 isolates (47%). MRPA isolates were detected in all clusters (except A) while pan-resistant isolates were recovered only in cluster C. The high prevalence of related or identical isolates in CF and non-CF patients can be due to transmission of particular dominant clones in ICU ward. Therefore, enhanced infection-control may become necessary to prevent further spread of clonal strains.

Antimicrobial resistance, plasmids and class 1 and 2 integrons occurring in Pseudomonas aeruginosa isolated from Brazilian aquatic environments

Pseudomonas aeruginosa is an important nosocomial pathogen also found in water, soil, plants and in human and animal fecal samples. In this study, 31 isolates from water samples were analyzed by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and PCR to detect integrons and investigated for antibiotic resistance and plasmidial profile. The results demonstrated the presence of plasmids in four isolates. Three of these, isolates from water in a city park (Curupira Park, Ribeirão Preto, Brazil) and a lake at the University of São Paulo (Campus of Ribeirão Preto), had plasmids with the same molecular weight (21MDa) and similar resistance profiles, although they were shown to be genetically different by ERIC-PCR. Class 1 and class 2 integrons were detected in one of these isolates. The results suggest that environmental P. aeruginosa strains may be a potential reservoir of plasmids and antibiotic resistance genes.

Shiga Toxigenic and Atypical EnteropathogenicEscherichia coliin the Feces and Carcasses of Slaughtered Pigs

Escherichia coli is a pathogen of major importance in swine and public health. To determine the prevalence of Shiga toxigenic E. coli (STEC) and enteropathogenic E. coli (EPEC), samples were collected from the feces and carcasses of swines. In total, 441 samples were collected in four samplings, of which 141 samples tested positive for either the stx1, stx2, and/or eae genes. From the positive samples, one STEC and 15 atypical EPEC (aEPEC) isolates were obtained, and all originated from the same sampling. In addition to eae, lpfA(O157/OI-141), ehxA, toxB, and lpfA(O113) were present in the aEPEC isolates. The only stx2-containing isolate carried stx2e and belonged to serotype O103:HNT. Resistance to four or more antimicrobials was found in almost half of the isolates, and some isolates shared the same fingerprint patterns by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The presence of certain virulence genes and the high level of resistance to antimicrobials, as well as the possible fecal contamination of carcasses showed that some of the isolates are of public health concern.

Resistance Characterization, Virulence Factors, and ERIC-PCR Fingerprinting ofAeromonas veroniiStrains Isolated from DiseasedTrionyx sinensis

Aeromonas veronii (AV) is an important pathogen causing severe diseases in aquaculture. Fifteen A. veronii strains isolated from diseased Trionyx sinensis from four aquafarms was characterized by enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR), antibiotic susceptibility testing, and identification of virulence factors. A. veronii strains were grouped into nine ERIC types with discriminatory ability (D) of 91.43 based on 90% similarity. The virulence genes were detected for 73% (aer), 80% (ast), 13% (alt), and 40% (act) of the strains, respectively, and five antibiotic resistance patterns with D of 0.829 were observed by antibiotic susceptibility testing. Furthermore, some AV isolates (AV1, AV2, AV3, and AV4) show the same characterization (the same ERIC types, presence of virulence genes in genomes, and antibiotics resistance).