Prevalence Of ST131 Research Articles

Genetic characterization and drug resistance analysis of Salmonella Kentucky ST314 in Shenzhen in 2010-2021

To understand the prevalence, genetic characteristics and drug resistance features of Salmonella Kentucky ST314 in Shenzhen. Whole genome sequencing of 14 strains of Salmonella Kentucky ST314 collected from 2010-2021 by the Foodborne Disease Surveillance Network of Shenzhen Center for Disease Control and Prevention for phylogenetic evolutionary analysis, drug resistance gene and plasmid detection; drug susceptibility experiments were performed by micro-broth dilution method. A total of 57 strains of Salmonella Kentucky were collected from the foodborne disease surveillance network, 14 of which were ST314. The Shenzhen isolates were clustered with isolates from Southeast Asian countries such as Vietnam and Thailand on clade 314.2, and the single nucleotide polymorphism distance between local strains in Shenzhen was large, indicating dissemination. In this study, a total of 17 drug resistance genes/mutations in 9 categories were detected in the genome of Salmonella Kentucky ST314, carrying 3 extended spectrum beta-lactamases(ESBLs), including bla_(CTX-M-24)(14.3%, 2/14), bla_(CTX-M-55)(7.1%, 1/14), and bla_(CTX-M-130)(14.3%, 2/14), all located on plasmids. Regarding quinolone resistance factors, two plasmid-mediated quinolone resistance(PMQR) genes were identified in the genome: qnrB6(71.4%, 10/14) and aac(6')Ib-cr(78.6%, 11/14), a quinolone resistance quinolone resistance-determining regions(QRDR) mutation T57 S(100%, 14/14). The multi-drug resistance rate of Salmonella Kentucky ST314 in Shenzhen was 92.86%(13/14)with the highest rate of resistance to tetracycline and cotrimoxazole(100%, 14/14), followed by chloramphenicol(92.86%, 13/14), cefotaxime and ampicillin(78.57%, 11/14), ciprofloxacin and nalidixic acid(71.43%, 10/14), and ampicillin-sulbactam had the lowest resistance rate(21.43%, 3/14). ST314 is the second most prevalent ST type among Salmonella Kentucky in Shenzhen, mainly isolated from food, especially poultry; phylogenetic analysis suggests that ST314 is a disseminated infection and the genome shows a highly genetically conserved phenotype. Drug resistance of Salmonella Kentucky ST314 is very serious, especially QRDR mutation, PMQR gene co-mediated quinolone resistance and plasmid-mediated cephalosporin resistance are prominent and deserve extensive attention.

Clinical and Molecular Characteristics of Patients with Bloodstream Infections Caused by KPC and NDM Co-Producing Carbapenem-Resistant Klebsiella pneumoniae.

Klebsiella pneumoniae carbapenemase (KPC) and New Delhi metallo-β-lactamase (NDM) co-producing carbapenem-resistant Klebsiella pneumoniae (KPC-NDM-CRKP) isolates have been increasingly reported worldwide but have not yet been systematically studied. Thus, we have conducted a study to compare the risk factors, molecular characteristics, and mortality involved in clinical bloodstream infections (BSIs) caused by KPC-NDM-CRKP and KPC-CRKP strains. A retrospective study was conducted on 231 patients with BSIs caused by CRKP at Jinling Hospital in China from January 2020 to December 2022. Antimicrobial susceptibility testing, carbapenemase genes detection and whole-genome sequencing were performed subsequently. Overall, 231 patients were included in this study: 25 patients with KPC-NDM-CRKP BSIs and 206 patients with KPC-CRKP BSIs. Multivariate analysis implicated ICU-acquired BSI, surgery within 30 days, and longer stay of hospitalization prior to CRKP isolation as independent risk factors for KPC-NDM-CRKP BSIs. The 30-day mortality rate of the KPC-NDM-CRKP BSIs group was 56% (14/25) compared with 32.5% (67/206) in the KPC-CRKP BSIs control group (P = 0.02). The ICU-acquired BSIs, APACHE II score at BSI onset, and BSIs caused by KPC-NDM-CRKP were independent predictors for 30-day mortality in patients with CRKP bacteremia. The most prevalent ST in KPC-NDM-CRKP isolates was ST11 (23/25, 92%), followed by ST15 (2/25, 8%). In patients with CRKP BSIs, KPC-NDM-CRKP was associated with an excess of mortality. The likelihood that KPC-NDM-CRKP will become the next "superbug" highlights the significance of epidemiologic surveillance and clinical awareness of this pathogen.

Genomic epidemiology of hypervirulent carbapenem-resistant Klebsiella pneumoniae at Jinshan local hospital, Shanghai, during 2014–2018

BackgroundHypervirulent carbapenem-resistant Klebsiella pneumoniae (Hv-CRKP) triggered a significant public health challenge. This study explored the prevalence trends and key genetic characteristics of Hv-CRKP in one Shanghai suburbs hospital during 2014–2018. MethodsDuring five years, Hv-CRKP strains identified from 2579 CRKP by specific PCR, were subjected to performed short- and long-read sequencing technology; epidemiological characteristics, antimicrobial-resistance genes (ARGs), virulence determinants, detailed plasmid profiles and conjugation efficiency were comprehensively investigated. Results155 Hv-CRKP and 31 non-Hv-CRKP strains were sequenced. Hv-CRKP strains exhibited significant resistance to six common antibiotic classes (>92%). ST11 steadily increased and became the most prevalent ST (85.2%), followed by ST15 (8.5%), ST65 (2.6%), ST23 (1.9%), and ST86 (0.6%). ST11-KL64 (65.2%) rapidly increased from 0 in 2014 to 93.9% in 2018. blaKPC-2 was the primary carbapenemase gene (97.4%). Other ARGs switched from aac(3)-IId to aadA2 in aminoglycoside and from sul1 to sul2 in sulfanilamide. The time-dated phylogenetic tree was divided into four independent evolutionary clades. Clade 1 and 3 strains were mostly limited in the ICU, whereas Clade 2 strains were distributed among multiple departments. Compared to ybt14 in ICEKp12 in Clade 1, Clade 3 strains harbored ybt9 in ICEKp3 and blaCTX-M-65. Hv-CRKP infected more wards than non-Hv-CRKP and showed greater transmission capacity. Three plasmids containing crucial carbapenemase genes demonstrated their early transmission across China. ConclusionThe Hv-CRKP ST11-KL64 has rapidly replaced ST11-KL47 and emerged as the predominant epidemic subtype in various hospital wards, highlighting the importance of conducting comprehensive early surveillance for Hv-CRKP, especially in respiratory infections.

Surveillance of the Antimicrobial Susceptibility and Molecular Characteristics of Neisseria gonorrhoeae Isolates Collected in Changsha, China from 2016 to 2021.

Antibiotic treatment is critical for individuals infected with gonorrhea and preventing disease transmission. This study aimed to analyze the antimicrobial susceptibility and molecular epidemiological characteristics of Neisseria gonorrhoeae isolates in Changsha, China. A total of 271 N.gonorrhoeae isolates collected from the clinical laboratories of two hospitals between 2016 and 2021 were analyzed for antimicrobial susceptibility using the agar dilution method. N. gonorrhoeae multi-antigen sequence typing (NG-MAST) was conducted for genotyping, and phylogenetic analysis was performed using the porB and tbpB sequences. The results showed that antimicrobial resistance against ciprofloxacin, tetracycline, and penicillin was high, and these drugs are no longer recommended for the treatment of gonorrhea. All isolates were susceptible to spectinomycin. However, in 2016-2021, a total of 15 (5.5%) ceftriaxone (CRO)-resistant strains and 31 (11.4%) isolates with decreased susceptibility to CRO were found, and the resistance rate to azithromycin had reached 7.1% in 2016-2017. Epidemiologically, the mosaic penA allele was identified in all CRO-resistant isolates. Based on NG-MAST, ST5061 was the most prevalent ST. Phylogenetic analysis suggested that the resistant isolates did not cluster independently. Despite focus on the local situation, this study raises the need for better gonorrhea medication and highlights that CRO may not be adequate as first-line treatment for gonorrhea in Changsha.

Genomic Determinants of Pathogenicity and Antimicrobial Resistance of Nosocomial Acinetobacter baumannii Clinical Isolates of Hospitalized Patients (2019-2021) from a Sentinel Hospital in Hangzhou, China.

Acinetobacter baumannii (A. baumannii or AB) is one of the most opportunistic, nosocomial pathogens threatening public healthcare across countries. A. baumannii has become a primary growing concern due to its exceptional ability to acquire antimicrobial resistance (AMR) to multiple antimicrobial agents which is increasingly reported and more prevalent every year. Therefore, there is an urgent need to evaluate the AMR knowledge of A. baumannii for effective clinical treatment of nosocomial infections. This study aimed to investigate the clinical distribution AMR phenotypes and genotypes, and genomic characteristics of A. baumannii isolates recovered from hospitalized patients of different clinical departments of a sentinel hospital to improve clinical practices. A total of 123 clinical isolates were recovered from hospitalized patients of different clinical departments during 2019-2021 to analyze AMR patterns, and further subjected to whole-genome sequencing (WGS) investigations. Multi-locus sequence typing (MLST), as well as the presence of antimicrobial-resistant genes (ARGs), virulence factor genes (VFGs) and insertion sequences (ISs) were also investigated from WGS data. The results highlighted that A. baumannii clinical isolates had shown a high AMR rate, particularly from the intensive care unit (ICU), towards routinely used antimicrobials, ie, β-lactams and fluoroquinolones. ST2 was the most prevalent ST in the clinical isolates, it was strongly associated to the resistance of cephalosporins and carbapenems, with blaOXA-23 and blaOXA-66 being the most frequent determinants; moreover, high carrier rate of VFGs was also observed such as all strains containing the ompA, adeF, pgaC, lpsB, and bfmR genes. Acinetobacter baumannii clinical isolates are mostly ST2 with high rates of drug resistance and carrier of virulence factors. Therefore, it requires measurements to control its transmission and infection.

Clonal Spread of Hospital-Acquired NDM-1-Producing Klebsiella pneumoniae and Escherichia coli in an Italian Neonatal Surgery Unit: A Retrospective Study.

This article reports a rapid and unexpected spread of colonization cases of NDM-1 carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in a neonatal surgical unit (NSU) at Bambino Gesù Children's Hospital in Rome, Italy. Between the 16th of November 2020 and the 18th of January 2021, a total of 20 NDM-1 carbapenemase-producing K. pneumoniae (n = 8) and E. coli (n = 12) were isolated from 17 out of 230 stool samples collected from neonates admitted in the aforementioned ward and time period by an active surveillance culture program routinely in place to monitor the prevalence of colonization/infection with multidrug-resistant Gram-negative microorganisms. All strains were characterized by antimicrobial susceptibility testing, detection of resistance determinants, PCR-based replicon typing (PBRT) and multilocus-sequence typing (MLST). All isolates were highly resistant to most of the tested antibiotics, and molecular characterization revealed that all of them harbored the blaNDM-1 gene. Overall, IncA/C was the most common Inc group (n = 20/20), followed by IncFIA (n = 17/20), IncFIIK (n = 14/20) and IncFII (n = 11/20). MLST analysis was performed on all 20 carbapenemase-producing Enterobacterales (CPE) strains, revealing three different Sequence Types (STs) among E. coli isolates, with the prevalence of ST131 (n = 10/12; 83%). Additionally, among the 8 K. pneumoniae strains we found 2 STs with the prevalence of ST37 (n = 7/8; 87.5%). Although patient results were positive for CPE colonization during their hospital stay, infection control interventions prevented their dissemination in the ward and no cases of infection were recorded in the same time period.

Genetic Diversity, Antibiotic Resistance, and Virulence Gene Features of Methicillin-Resistant Staphylococcus aureus Epidemics in Guiyang, Southwest China.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common pathogens of community- and hospital-acquired infections, and its prevalence is increasing globally. Guiyang is the capital city of Guizhou Province, Southwest China; as the transport and tourism centre of Southwest China, Guizhou Province is bordered by Yunnan, Sichuan, Chongqing, and Guangxi Provinces. Although MRSA prevalence is increasing, little is known about its aspects in the area. The purpose of this study was to analyse MRSA molecular characteristics, antimicrobial resistance, and virulence genes in Guiyang. In total, 209 MRSA isolates from four hospitals (2019-2020) were collected and analysed by antimicrobial susceptibility testing and molecular classification by the MLST, spa, and SCCmec typing methods. Isolate antibiotic resistance rates were detected by a drug susceptibility assays. PCR amplification was used to detect the virulence gene-carrying status. Twenty-four STs, including 4 new STs (ST7346, ST7347, ST7348, and ST7247) and 3 new allelic mutations, were identified based on MLST. The major prevalent ST type and clone complex were ST59 (49.8%) and CC59 (62.7%), respectively. Spa type t437 (42.1%) and SCCmec IV (55.5%) were identified by spa and SCCmec typing methods as the most important types. Drug sensitivity data showed that the multidrug resistance rate was 79.0%. There were significant differences in multidrug resistance rates and virulence gene-carrying rates for seb, hla, hlb, cna and bap between ST59 and non-ST59 types. ST59-SCCmecIV-t437 is a major epidemic clone in Guiyang that should be monitored by local medical and health institutions. The situation differs from other adjacent or middle provinces of China, which may be due to the special geographical location of the region and the trend in antibiotic use or lifestyle. This study provides empirical evidence for local medical and health departments to prevent and control the spread of MRSA.

Changes in the characteristics of community-onset fluoroquinolone-resistant Escherichia coli isolates causing community-acquired acute pyelonephritis in South Korea.

This study aimed to examine the changes in the characteristics of community-onset fluoroquinolone-resistant (FQ-R) Escherichia coli isolates causing community-acquired acute pyelonephritis (APN) in South Korea. Blood or urine samples were prospectively collected from patients aged ≥15 years with community-acquired APN who were admitted to one of the eight Korean hospitals included in this study between September 2017 and August 2018. Phylogenetic typing, multilocus sequence typing, and molecular characterization of β-lactamase resistance and plasmid-mediated quinolone resistance (PMQR) determinants were performed. The data were compared with those from a previous study with the same design conducted in 2010-2011. A total of 300 and 346 isolates were identified in 2010-2011 and 2017-2018, respectively. Among them, 76 (22.0%) and 77 (25.7%) FQ-R isolates were identified in 2010-2011 and 2017-2018, respectively. A significantly higher antimicrobial resistance against third-to fourth-generation cephalosporins, including cefotaxime (23.9% vs. 77.9%, P<0.001), were observed among FQ-R isolates in 2017-2018 than among those in 2010-2011. A higher proportion of ST131 isolates (27.6% vs. 66.2%, P<0.001), as well as isolates that had extended-spectrum β-lactamase (ESBL)/plasmid-mediated AmpC β-lactamase (PABL) (23.7% vs. 79.2%, P<0.001), was observed in 2017-2018 than in 2010-2011. Further, more PMQR determinants (11.8% vs. 40.8%, P<0.001) were observed in 2017-2018 than in 2010-2011. Among uropathogenic FQ-R E. coli isolates in South Korea, the prevalence of ST131 and the proportion of isolates containing ESBL and/or PMQR determinants have increased.

Genomic epidemiology, antimicrobial resistance and virulence factors of Enterobacter cloacae complex causing potential community-onset bloodstream infections in a tertiary care hospital of Nepal.

ObjectivesCommunity-onset bloodstream infections (BSIs) caused by carbapenemase-producing Enterobacter cloacae complex (ECC) species are increasing internationally. This observation suggests that ECC are emerging pathogens, requiring for detailed understanding on their genomic epidemiology including transmission dynamics and antimicrobial resistance profiles.Patients and methodsWe performed WGS on 79 Enterobacter spp. isolated from the patients with clinically significant BSIs and admitted to emergency department of a major tertiary hospital in Nepal between April 2016 and October 2017.ResultsWe identified 5 species and 13 STs of ECC. Enterobacter xiangfangensis ST171, one of the globally emerging carbapenem resistant ECC clones with epidemic potential, was the most prevalent (42%). Phylogenetic analysis showed a large (>19 400 SNPs) core genome SNP distance across major STs, which was minimal (<30 SNPs) among the isolates of each prevalent ST, suggesting the relatively recent importation of major STs followed by local clonal expansions. Genomic evidence for resistance to all major antimicrobial classes except for colistin and macrolides was detected. A limited number of isolates also carried blaNDM-1 (n = 2) and blaOXA-48 (n = 1) carbapenemase genes. Virulence factors encoding siderophores (24%), T6SSD (25%) and fimbriae (54%) were detected.ConclusionsOur study highlighted that MDR ECC clones are important pathogens of BSIs in community. Though of low prevalence, carbapenem resistance observed in our ECC isolates raised concern about further community dissemination, underscoring the need for community surveillance to identify MDR ECC clones with epidemic potential.

Community Fecal Carriage and Molecular Epidemiology of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Escherichia coli from Healthy Children in the Central South China.

BackgroundFecal carriage of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) and carbapenemase-producing E. coli (CP-EC) is well reported among hospitalized adults and children. However, there are few studies on the carriage prevalence and ESBL-EC and CP-EC genotypes among healthy children in China.Patients and MethodsStool samples were collected from 330 students in 2021 from three randomly selected primary schools in Changsha, China. ESBL-EC and CP-EC were screened using CHROMagarTM chromogenic plates. ESBL and carbapenemase production was confirmed using the double-disc synergy test and a modified carbapenem inactivation method, respectively. Antimicrobial susceptibility was tested using the broth microdilution method. Resistance determinants, virulence factors, and phylogenetic groups were determined by PCR and sequencing. Multi-locus sequence typing (MLST) was performed (seven housekeeping genes were amplified and sequenced) on the phylogenic group B2 E. coli to detect high-risk clonal strains such as ST131 E. coli. Then, ST131 E. coli were characterized based on ST131 clades, O-type, and fimH alleles.ResultsIn total, 118 (35.8%) ESBL-EC and 3 (0.9%) CP-EC were isolated. blaCTX-M was the most common genotype (27.1%), identified in all ESBL-EC, except one, which carried blaSHV-12. One isolate with mcr-1 was found amongst ESBL-EC, whereas all three CP-EC carried blaNDM-1. The predominant sequence type (ST) clones in group B2 were ST131 and ST1193. The prevalence of ST131 E. coli was 9.9%, displaying serotypes O16 and O25b, fimH alleles 30, 41, and 89, and ST131 clades A and C1-M27.ConclusionIn this study, high carriage rate of ESBL-EC was found among healthy children, and the dominant ESBL was CTX-M-14. In addition, high-risk clones (ST131 and ST1193) were also detected. This emphasizes the importance of monitoring ESBL-EC in community settings.

Emergence of Carbapenem-Resistant ST244, ST292, and ST2446 Pseudomonas aeruginosa Clones in Burn Patients in Yunnan Province.

IntroductionThe prevalence of carbapenem-resistant Pseudomonas aeruginosa is increasing persistently, particularly in burn ward isolates. Here, we investigate the prevalence of carbapenem-resistant Pseudomonas aeruginosa in a burn ward of a provincial-level hospital at Kunming, Yunnan province, China.MethodsA total of 118 P. aeruginosa strains were isolated from 57 hospitalized patients, and their MICs were measured. Carbapenem-resistant isolates were selected for multilocus sequence typing (MLST). Carbapenem-resistance mechanisms were identified by examining carbapenemase genes and OprD protein and Carba-NP testing. Representative isolates were further characterized by de novo sequencing for carbapenemase molecular background.ResultsAmong 118 P. aeruginosa isolates, 54 (54/118,45.8%) were carbapenem-resistant Pseudomonas aeruginosa, and 3 genotypes were found (ST292, ST244, and ST2446). Non-carbapenemase-producing ST292 was the most prevalent ST, followed by ST2446 and ST244. A novel 13-bp oprD deletion was found in the ST292 clone, which formed the truncated outer membrane protein and may cause carbapenem resistance. ST244 and ST2446 harbored blaIMP-45 and blaIMP-87, respectively. blaIMP-45 is located in a megaplasmid, together with aac(6’)-Ib3, blaOXA-1, catB3, qnrVC6, armA, msr(E), mph(E), aph(3’)-Ia, tetC/tetR, aac(6’)-Ib3, floR, mexC-mexD-oprJ, fosA and lead to extensive drug resistance. ST2446 contains a carbapenem-resistant gene blaIMP-87 on the chromosome and is acquired by a novel gene cassette array (blaIMP-87-ant(2”)-Ia-blaOXA-10-aac(6’)-Ib3) of class 1 integron.DiscussionFor the first time, ST244, ST292 and ST2446 are reported emerging in burn patients, with distinctive carbapenem-resistance mechanisms, respectively. The obtained results highlight the need to surveillance carbapenem-resistant isolates in burn patients.

Characterization of Haemophilus influenzae Strains with Non-Enzymatic Resistance to β-Lactam Antibiotics Caused by Mutations in the PBP3 Gene in the Czech Republic in 2010-2018.

The surveillance data on antibiotic resistance of Haemophilus influenzae have shown that strains with non-enzymatic resistance to β-lactam antibiotics have been on the rise in the Czech Republic over the last decade. This type of resistance is more difficult to detect than β-lactamase production. Analysis of 228 H. influenzae strains revealed that isolates with non-enzymatic resistance to β-lactams due to mutations in the ftsI gene could be reliably demonstrated by single run testing of susceptibility to amoxicillin/clavulanic acid (sensitivity of detection is 84.6%), cefuroxime (92.6%), ampicillin and penicillin (both 95.7%). Thirty-seven different amino acid substitution combinations were detected in the PBP3 protein at 23 positions (V329I, D350N, S357N, A368T, M377I, S385T, A388V, L389F, P393L, A437S, I449V, G490E, I491V, R501L, A502S, A502T, A502V, V511A, R517H, I519L, N526K, A530S, and T532S). The most common combination (35%) of amino acid substitutions was the combination D350N, M377I, A502V, N526K. Epidemiological typing does not indicate a clonal spread of a particular MLST type. Altogether there has been detected 74 STs. The most prevalent ST 1034 was associated mainly with a combination D350N, M377I, A502V, N526K. Clonal analysis revealed six clonal complexes (CCs) with the founder found, eight CCs without founder and 33 singletons.

Clonal/subclonal changes and accumulation of CTX-M-type β-lactamase genes in fluoroquinolone-resistant Escherichia coli ST131 and ST1193 strains isolated during the past 12 years, Japan

Fluoroquinolone (FQ)- and third-generation cephalosporin-resistant Escherichia coli are increasing in Japan. In the early 2000s, the FQ-resistant E. coli clone ST131 increased in clinical settings worldwide. It frequently produces extended-spectrum β-lactamases (ESBLs) such as CTX-M. This study aimed to explore the characteristics of FQ-resistant E. coli isolated in Japan during 2008-2009 and 2020. We compared FQ-resistant E. coli clinical isolates from urine samples collected in 2020 (151 isolates) with a FQ-resistant E. coli collection isolated in 2008-2009 (42 isolates). Identification of E. coli ST131 clades and blaCTX-M were determined by multiplex PCR. Sequence types of non-ST131 isolates were determined by whole-genome sequencing. Although the prevalence of ST131 was comparable in 2020 (74.2%) and 2008-2009 (78.6%), the subclades differed during the two time periods (C1-nM27: 40.2% in 2008-2009 vs. 78.8% in 2020; C1-M27: 32.1% in 2008-2009 vs. 9.1% in 2020). The incidence of blaCTX-M among ST131 isolates increased from 27.3% in 2008-2009 to 64.3% in 2020. blaCTX-M was found in 80.6% and 93.8% of C1-M27 and C2 in 2020, respectively, and blaCTX-M possession in C1-nM27 increased from 19.2% in 2008-2009 to 40% in 2020. FQ-resistant ST1193 was detected only in 2020 (17.9% of 151 isolates, of which 14.8% possessed blaCTX-M). Increased resistance of E. coli to FQs and third-generation cephalosporins in Japan can be attributed to the accumulation of blaCTX-M in C1-nM27 and the increase of C1-M27 and C2 clades with high blaCTX-M possession, alongside the spread of ST1193.

Epidemiologic Characteristics of ESBL-Producing ST131 E. coli Identified Through the Emerging Infections Program, 2017

Background: Extended-spectrum β-lactamase–producing (ESBL) Escherichia coli infection incidence is increasing in the United States. This increase may be due to the rapid expansion of ST131, which is now the predominant ESBL strain globally, often multidrug resistant, and has been shown to establish longer-term human colonization than other E. coli strains. We assessed potential risk factors that distinguish ST131 from other ESBL E. coli. Methods: From October 1 through December 31, 2017, 5 CDC Emerging Infections Program (EIP) sites pilot tested active, laboratory-based surveillance in selected counties in Colorado, Georgia, New Mexico, New York, and Tennessee. An E. coli case was defined as the first isolation from a normally sterile body site or urine in a surveillance area resident in a 30-day period resistant to 1 extended-spectrum cephalosporin antibiotic and susceptible or intermediate to all carbapenem antibiotics tested. Epidemiologic data were collected from case patients’ medical records. A convenience sample of 117 E. coli isolates from case patients was collected. All isolates underwent whole-genome sequencing to determine sequence type and the presence of ESBL genes. We compared ST131 E. coli epidemiology to other ESBL E. coli. Results: Among 117 E. coli isolates, 97 (83%) were ESBL producers. Of the 97 ESBL E. coli, 52 (54%) were ST131 (range, for 4 EIP sites submitting &gt;10 isolates: 25%–88%; P &lt; .001). Other common STs were ST38 (12%) and ST10 (5%). ST131 infections were more likely to be healthcare-associated than non-ST131 (56% vs 36%; P = .05) (Table 1). Among specific prior healthcare exposures, only residence in long-term care facilities (LTCFs) in the year before culture was more common among ST131 case patients (29% vs 11%; P = .03). Notably, 85% of ESBL E. coli collected from LTCF residents were ST131. ST131 E. coli were more common among patients with underlying medical conditions (81% vs 60%; P = .02). No statistically significant difference by sex, race, age, culture source, location of culture collection, and frequency of antibiotic use in the prior 30 days was observed. Conclusions:The prevalence of ST131 E. coli varies regionally. The association between ST131 and LTCFs suggests that these may be particularly important settings for ST131 acquisition. Improving infection control measures that limit ESBL transmission in these settings and preventing dissemination in facilities receiving patients from LTCFs may be necessary to contain ST131 spread.Funding: NoneDisclosures: None

Antimicrobial resistance, genetic characterization, and molecular epidemiology of Ureaplasma species in males with infertility.

This study aimed to study the antimicrobial resistance, genetic characterization, and molecular epidemiology of Ureaplasma species in order to provide clinicians sufficient data to select optimal strategies of treatment for genitourinary tract infections of infertile male patients. Firstly, a total of 817 clinical semen specimens were detected for Ureaplasma species by molecular detection. Secondly, culture and identification of Ureaplasma species were achieved by using Mycoplasma ICS Test, and the antimicrobial susceptibility tests were determined by using broth microdilution assay. Then, the tetracycline resistance genetic determinants in Ureaplasma species were identified by PCR, and the fluoroquinolone and macrolide resistance genetic determinants were identified by DNA sequencing. Finally, the molecular epidemiology of Ureaplasma species was studied by both multilocus sequence typing (MLST) and expanded MLST (eMLST) schemes. Among the 817 semen specimens, 320 (39.17%) specimens were positive for Ureaplasma species. The percentages of resistance in 320 isolates against LEV, MXF, TET, and ERY were 47.5%, 39.38%, 19.69%, and 3.75%, respectively. The tet(M) and int-Tn genes were detected positive in all the tetracycline-resistant isolates. One macrolide-resistant UU isolate had a novel amino acid alteration (R66T) in L4 ribosomal protein and another UU isolate harbored a novel alteration (S109T) in L22. In fluoroquinolone-resistant isolates, S83L substitution in the ParC was predominant. In this area, ST22 and eST16 were the most prevalent ST and eST, respectively. One ST and 3 eSTs were newly identified in this study. This study has demonstrated that ERY can be first-line therapy for Ureaplasma species infections.

Extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing Escherichia coli isolates causing bacteremia in the Netherlands (2014 – 2016) differ in clonal distribution, antimicrobial resistance gene and virulence gene content

Knowledge on the molecular epidemiology of Escherichia coli causing E. coli bacteremia (ECB) in the Netherlands is mostly based on extended-spectrum beta-lactamase-producing E. coli (ESBL-Ec). We determined differences in clonality and resistance and virulence gene (VG) content between non-ESBL-producing E. coli (non-ESBL-Ec) and ESBL-Ec isolates from ECB episodes with different epidemiological characteristics. A random selection of non-ESBL-Ec isolates as well as all available ESBL-Ec blood isolates was obtained from two Dutch hospitals between 2014 and 2016. Whole genome sequencing was performed to infer sequence types (STs), serotypes, acquired antibiotic resistance genes and VG scores, based on presence of 49 predefined putative pathogenic VG. ST73 was most prevalent among the 212 non-ESBL-Ec (N = 26, 12.3%) and ST131 among the 69 ESBL-Ec (N = 30, 43.5%). Prevalence of ST131 among non-ESBL-Ec was 10.4% (N = 22, P value < .001 compared to ESBL-Ec). O25:H4 was the most common serotype in both non-ESBL-Ec and ESBL-Ec. Median acquired resistance gene counts were 1 (IQR 1-6) and 7 (IQR 4-9) for non-ESBL-Ec and ESBL-Ec, respectively (P value < .001). Among non-ESBL-Ec, acquired resistance gene count was highest among blood isolates from a primary gastro-intestinal focus (median 4, IQR 1-8). Median VG scores were 13 (IQR 9-20) and 12 (IQR 8-14) for non-ESBL-Ec and ESBL-Ec, respectively (P value = .002). VG scores among non-ESBL-Ec from a primary urinary focus (median 15, IQR 11-21) were higher compared to non-ESBL-Ec from a primary gastro-intestinal (median 10, IQR 5-13) or hepatic-biliary focus (median 11, IQR 5-18) (P values = .007 and .04, respectively). VG content varied between different E. coli STs. Non-ESBL-Ec and ESBL-Ec blood isolates from two Dutch hospitals differed in clonal distribution, resistance gene and VG content. Also, resistance gene and VG content differed between non-ESBL-Ec from different primary foci of ECB.

Molecular surveillance of brazilian meningococcal isolates serogroup c in the pre and post-men-c-vaccination period: Emergence of ST-3780

Meningococcal disease is a devastating infection caused by Neisseria meningitidis (meningococcus), and it is classified into serogroups according to its polysaccharide capsule composition. In Brazil, serogroup C is the most frequently responsible for the majority of cases, representing a serious public health challenge. In 2010, the meningococcal serogroup C conjugate vaccine was included in the calendar of the National Immunization Program. We have evaluated 163 meningococcal isolates collected during the pre (2006–2010) and post (2011–2016) vaccination periods. Epidemiological data were determined through Multilocus Sequence Typing (MLST) analysis, vaccine antigens and Bexsero Antigen Sequence Typing (BAST) variant. Clonal complex 103 remains the most prevalent in the country with a high number of serogroup C strains to which CC103 is directly associated. A total of 42 different ST were found. The two most prevalent ST were ST-3780 (CC103) with 38 strains and ST-10781, which was not associated with a CC with nine strains. Allele abcZ-276 was reported among 98% of the strains analyzed and it was not found among other CC103 strains worldwide, makes this allele an important genetic marker for a specific new clone only assigned to Brazilian serogroup C strains, ST-3780. FHbp-25 and NHBA-42 peptides were the most prevalent among isolates in both periods studied. BAST-824 and BAST-3073 have been expressed only in CC103 over the studied years, however, it was not possible to associate a BAST variant to a specific CC. Serogroup C phenotype [P1.22,14-6,36-2: F3-9: ST-3780 (CC103)] was the most prevalent according to the antigenic profiles of circulating strains in Brazil (2007–2016). Our study suggests that CC103 is still a major hypervirulent CC circulating in Brazil and ST-3780 is currently spreading all over the country even after the introduction of MenC in 2010.

Characterization of the Multi-Drug Resistance Gene cfr in Methicillin-Resistant Staphylococcus aureus (MRSA) Strains Isolated From Animals and Humans in China.

We investigated cfr-positive and -negative MRSA strains isolated from animals and humans in different geographical areas of China, from 2011 to 2016. Twenty cfr-positive strains (15.6%) were identified from 128 MRSA strains including 17 from food animals and three from humans. The resistance rates and prevalence of the tested antibiotic resistance genes (ARGs) in the cfr-positive MRSA isolates were higher than that in the cfr-negative MRSA isolates. All cfr-positive MRSA isolates were co-carrying fexA and ermC, and had significantly higher optrA incidence rate vs. the cfr-negative isolates (P < 0.05). In addition, multilocus sequence typing (MLST) assays showed that ST9 and spa-type t899 were the most prevalent ST and spa types in the study strains. However, all of the 20 cfr-positive and 10 randomly selected cfr-negative MRSA isolates were clonally unrelated as determined by pulsed-field gel electrophoresis (PFGE) analyses. Importantly, the cfr gene was successfully transferred to a recipient Staphylococcus aureus strain RN4220 from 13 of the 20 cfr-positive MRSA isolates by electroporation. Among these 13 cfr-positive MRSA isolates, two different genetic contexts surrounding cfr were determined and each was associated with one type of cfr-carrying plasmids. Of note, the predominant genetic context of cfr was found to be a Tn558 variant and locate on large plasmids (∼50 kb) co-harboring fexA in 11 of the 13 MRSA isolates. Furthermore, the cfr gene was also identified on small plasmids (∼ 7.1 kb) that co-carried ermC in two of the 13 MRSA isolates. Our results demonstrated a high occurrence of multi-drug resistance in cfr-positive MRSA isolates, and the spread of cfr might be attributed to horizontal dissemination of similar cfr-carrying transposons and plasmids.

High Prevalence of Extended-Spectrum β-Lactamase Producing Enterobacteriaceae Among Clinical Isolates From Cats and Dogs Admitted to a Veterinary Hospital in Switzerland

This study aimed to identify and characterize extended-spectrum β-lactamase (ESBL) producing Enterobacteriaceae among clinical samples of companion animals. A total of 346 non-duplicate Enterobacteriaceae isolates were collected between 2012 and 2016 from diseased cats (n = 115) and dogs (n = 231). The presence of blaESBL, PMQR genes, and the azithromycin resistance gene mph(A) was confirmed by PCR and sequencing of bla genes. Isolates were further characterized by antimicrobial resistance profiling, multilocus sequence typing, phylogenetic grouping, identification of mutations in the QRDR of gyrA and parC, and screening for virulence-associated genes. Among the 346 isolates, 72 (20.8%) were confirmed ESBL producers [58 Escherichia coli (E. coli), 11 Klebsiella pneumoniae (K. pneumoniae), and 3 Enterobacter cloacae]. The strains were cultured from urine (n = 45), skin and skin wounds (n = 8), abscesses (n = 6), surgical sites (n = 6), bile (n = 4), and other sites (n = 3). ESBL genes included blaCTX-M-1, 14, 15, 27, 55, and blaSHV-12, predominantly blaCTX-M-15 (54.8%, 40/73), and blaCTX-M-1 (24.7%, 18/73). Further genes included qnrB (4.2%, 3/72), qnrS (9.7%, 7/72), aac(6')-Ib-cr (47.2%, 34/72), and mph(A) (38.9%, 28/72). Seventeen (23.6%) isolates belonged to the major lineages of human pathogenic K. pneumoniae ST11, ST15, and ST147 and E. coli ST131. The most prevalent ST was E. coli ST410 belonging to phylogenetic group C. The high prevalence of ESBL producing clinical Enterobacteriaceae from cats and dogs in Switzerland and the presence of highly virulent human-related K. pneumoniae and E. coli clones raises concern about transmission prevention as well as infection management and prevention in veterinary medicine.

Molecular epidemiology of Escherichia coli sequence type 131 and its H30/H30-Rx subclones recovered from extra-intestinal infections: first report of OXA-48 producing ST131 clone from Iran.

Multidrug-resistant (MDR) O25b-ST131 clone of Escherichia coli is well established as a significant cause of extra-intestinal infections worldwide. However, there have been no studies about the prevalence of ST131 and its H30/H30Rx subclones from Iran. The prevalence of ST131 was 29.8% among phylogroups B2, D, and F of E.coli isolates recovered from extra-intestinal infections. Fifty-seven (90.4%) and six (9.6%) of isolates belonged to serogroups O25b and O16 respectively, and exhibited high rates of MDR (98.4% and 83.3%) and extended spectrum β-lactamase (ESBL) production (96.8% and 83.3%). The majority (56/57, 98.2%) of O25b isolates belonged to H30 lineage; of those, 24 isolates (42.8%) belonged to H30-Rx subclone. O16-ST131 isolates were H30-negative. The resistance rate values of O16-ST131subgroup were lower for fluoroquinolones/aminoglycosides and higher for carbapenems, cephalosporins, β-lactam/β-lactamase inhibitors and trimethoprim/sulfamethoxazole, as compared to O25b-ST131 isolates. Among H30 sub lineage and in comparison with non-Rx isolates, H30-Rx subclone showed higher resistance score and virulence genes (papA and papC), and was also associated with CTX-M group 1. bla OXA-48 carbapenemase was detected in seven O25b and one O16 isolates; of those, one O25b-ST131 isolate was carbapenem-susceptible. The ST131 isolates comprised 15 'enterobacterial repetitive intergenic consensus' (ERIC) clusters, and O16 isolates remained distributed in five groups in cluster with O25b-ST131 isolates. In conclusion, this is the first report of the presence of MDR, bla OXA-48/CTX-M-positive O25b/O16-ST131 isolates in Iran. Contrary to lower prevalence of O16-ST131 subgroup, higher resistance rates to β-lactam antibiotics may indicate the importance of this subgroup in the spread of MDR E.coli isolates.