Objective: Legionella pneumophila serogroup 1 (Lp1) sequence type (ST) 1 is globally widespread in the environment and accounts for a significant proportion of Legionella infections, including nosocomial Legionnaires' disease (LD). This study aimed to design a sensitive and specific detection method for Lp ST1 that will underpin epidemiological investigations and risk assessment. Methods: A total of 628 Lp genomes (126 ST1s) were analyzed by comparative genomics. Interrogation of more than 900 accessory genes revealed seven candidate targets for specific ST1 detection and specific primers and hydrolysis probes were designed and evaluated. The analytical sensitivity and specificity of the seven primer and probe sets were evaluated on serially diluted DNA extracted from the reference strain CIP107629 and via qPCR applied on 200 characterized isolates. The diagnostic performance of the assay was evaluated on 142 culture-proven clinical samples from LD cases and a real-life investigation of a case cluster. Results: Of seven qPCR assays that underwent analytical validation, one PCR target (lpp1868) showed higher sensitivity and specificity for ST1 and ST1-like strains. The diagnostic performance of the assay using respiratory samples corresponded to a sensitivity of 95% (19/20) (95% CI (75.1-99.9)) and specificity of 100% (122/122) (95% CI (97-100)). The ST1 PCR assay could link two out of three culture-negative hospitalized LD cases to ST1 during a real-time investigation. Conclusion: Using whole genome sequencing (WGS) data, we developed and validated a sensitive and specific qPCR assay for the detection of Lp1 belonging to the ST1 clonal complex by amplification of the lpp1868 gene. The ST1 qPCR is expected to deliver an added value for Lp control and prevention, in conjunction with other recently developed molecular assays. C. Ginevra, Clin Microbiol Infect 2020;26:514.e1-514.e6 (c) 2019 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

TPS 751: Farms, antibiotics, infections, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: campylobacter species have emerged as leading bacterial causes of gastroenteritis and foodborne infections in developed countries. The incidence-rate in Israel, one of the highest world-wide, increased from 31:100,000 to 91 during 1999–2010. We aimed to explore the effect of spatio-ecological factors (e.g. socio-economic-status (ses)) and time-spatial factors (e.g. ambient temperature) on the infection incidence in Israel; and to pinpoint areas with increased risks. Methods: data on 35,542 incident cases was provided by the reference laboratories of the Israeli ministry of health for the period 1999-2010. Case characteristics included isolate date, species identification (c. jejuni or c. coli), age and street-address that was geo-coded into spatial areas. The spatio-temporal study unit was region (1,824 units)* season (48 seasons). we calculated the standardized incidence ratio, adjusted for age-group and nationality, for each study unit and applied bayesian hierarchical spatio-temporal models to estimate relative risk (rr) and 95%ci for the ecological determinants (ses, temperature, population-density and altitude) and for mapping disease risk. Results: we found significant effects of ses, altitude, population-density and temperature on campylobacter infection risk. For ses, rr was 1.107 (95%ci=1.062-1.153, standardized values -3 to +3), for altitude rr was 1.14 (95%ci=1.11-1.15 for 100 meters), for population-density rr was 0.881 (95%ci=0.860- 0.904, log), and for temperature rr was 1.025 (95%ci=1.013-1.038, for 10c). Across seasons, the higher risk was found in the spring (RR=1.150, 95%ci=1.061, 1.241, compared to winter). Among the six Israeli districts, the highest risk was found in the southern district showing increased risk in many regions throughout the year. In Haifa district (northern-israel), unlike other districts, there were a few regions with very high risks and the rest without an increased risk. Conclusions: campylobacter infection in Israel is multifactorial and associated with environmental factors. The finding of a spatio-temporal ambient-temperature effect should be considered in climate-change adaptation strategies.

This study analyses the epidemiologic, clinical and molecular findings of all culture-confirmed cases of listeriosis notified from 2010 to 2015 in the Tel Aviv District, which is known to have high rates of listeriosis. All clinical isolates of Listeria monocytogenes were subtyped using two-enzyme pulsed-field gel electrophoresis. During the studied period, 102 cases of listeriosis were notified, including 23 pregnancy-associated cases (23%). Among 79 non-pregnancy-associated cases, 18 had neuro-invasive disease (21%). There were 26 deaths associated with the disease. Using molecular identification, we found a number of clusters of identical bacterial clones, which pointed to possible sources of infection. The high rates of morbidity and mortality resulting from listeriosis, as well as the diverse ways of infection demonstrated in this study, accentuate the need to boost public health actions, in order to raise awareness and better control high-risk contamination routes.

SUMMARY Shiga toxin-producing Escherichia coli (STEC) is a significant cause of gastrointestinal infection and the haemolytic-uremic syndrome (HUS). STEC outbreaks are commonly associated with food but animal contact is increasingly being implicated in its transmission. We report an outbreak of STEC affecting young infants at a nursery in a rural community (three HUS cases, one definite case, one probable case, three possible cases and five carriers, based on the combination of clinical, epidemiological and laboratory data) identified using culture-based and molecular techniques. The investigation identified repeated animal contact (animal farming and petting) as a likely source of STEC introduction followed by horizontal transmission. Whole genome sequencing (WGS) was used for real-time investigation of the incident and revealed a unique strain of STEC O26:H11 carrying stx2a and intimin. Following a public health intervention, no additional cases have occurred. This is the first STEC outbreak reported from Israel. WGS proved as a useful tool for rapid laboratory characterization and typing of the outbreak strain and informed the public health response at an early stage of this unusual outbreak.

Objectives: Whole genome sequencing (WGS) has revolutionized the subtyping of Legionella pneumophila but calling the traditional sequence-based type from genomic data is hampered by multiple copies of the mompS locus. We propose a novel bioinformatics solution for rectifying that limitation, ensuring the feasibility of WGS for cluster investigation.Methods: We designed a novel approach based on the alignment of raw reads with a reference sequence. With WGS, reads originating from either of the two mompS copies cannot be differentiated. Therefore, when non-identical copies were present, we applied a read-filtering strategy based on read alignment to a reference sequence via unique 'anchors'. If minimal read coverage was achieved after filtration (>= 3X), a consensus sequence was built based on mapped reads followed by calling the sequence-based typing allele. The entire procedure was implemented using a Perl script.Results: The method was validated using a diverse sample of 265 L. pneumophila genomes, consisting of 59 different sequence types (STs) and 23 mompS variants; 57 of the 265 (22%) had non-identical mompS copies. In 237 of the 265 samples (89.4%), mompS calling was successful and no erroneous calling occurred. A 98.1% success was recorded among 109 samples meeting quality requirements. The method was superior to alternative approaches.Conclusions: As WGS becomes more accessible, technical difficulties in routine clinical and surveillance work will arise. The case of mompS in L. pneumophila serves as an example for such limitations that necessitate the development of novel computational solutions that meet end-user demands. M. Gordon, Clin Microbiol Infect 2017;23:306 (C) 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Beta-hemolytic group G streptococci (GGS) are increasingly recognized as a source of substantial morbidity, causing mild to severe sporadic infections as well as outbreaks. The purpose of this study was to determine the genetic diversity and antibiotic resistance of GGS in Israel in order to aid in prevention and control. A total of 325 GGS isolates were collected in Israel between 2007 and 2011 from three determined settings: (1) carriage (n = 60), an observational longitudinal carriage study in the IF, (2) non-invasive (n = 166), clinical sporadic and epidemic non-invasive cases in the IDF, and (3) invasive (n = 99) cases of bacteremia collected during this period in Israel from a similar age group, at the national Streptococcal Reference Center. All isolates were characterized genetically and by their antibiotic-resistance profile. emm typing revealed 35 distinct types and subtypes among 228 S. dysgalactiae subsp. equisimilis (SDSE) isolates, with high genetic diversity. An additional 97 GGS were identified as Streptococcus anginosus (SAG). The proportion of SDSE was higher in the invasive (100 %) and non-invasive (63.8 %) isolates compared to the carriage ones (38.3 %). Clindamycin, erythromycin, azithromycin and tetracycline resistance was detected in 6.6 %, 8.6 %, 9.7 % and 37.6 % of isolates, respectively. Overall, the most resistant isolates were in the invasive group and the fewest were in the SAG group. Considerable genetic diversity and common antibiotic resistance were revealed among GGS strains which differed according to the epidemiologic settings. Further clinical, epidemiological and basic research of GGS as a pathogen is warranted.

The incidence of Campylobacter infection in Israel, particularly among children <2 years of age, has risen over the last decade and became one of the highest among industrialized countries. This study explored the molecular epidemiology of Campylobacter jejuni in Israel over a decade (2003-2012) using multi-locus sequence typing (MLST) combined with demographic metadata. Representative clinical isolates (438) from a large national repository together with selected veterinary isolates (74) were subject to MLST. The distribution of age groups, ethnicity and clinical source across various genotypes was evaluated using Poisson modelling. The 512 studied isolates were assigned 126 distinct sequence types (STs) (18.8% novel STs) grouped into 21 clonal complexes (CCs). Most human, poultry and bovine STs clustered together in the leading CCs. Three dominant STs (ST21, ST6608, ST4766) were detected only since 2006. Patients infected with the leading CCs were similarly distributed along densely populated areas. The frequency of blood isolates was higher in patients infected with CC353 (relative rate (RR) = 2.0, 95% CI 1.03-3.9, adjusted p value (adj.p) 0.047) and CC42 (RR = 4.4, 95% CI 1.7-11.6, adj. p 0.018) and lower with CC257 (RR = 0.3, 95% CI 0.1-0.9, adj. p 0.047). The distribution of age groups and ethnicity also varied across the leading CCs.In conclusion, C. jejuni isolates in a national sample appeared highly diverse with a high proportion of new STs. Phylogenic analysis was compatible with poultry and cattle as possible food sources of clinical infection. Demographic characteristics of the infected patients coupled with strain invasiveness across different genotypes revealed a complex epidemiology of C. jejuni transmission in Israel. (C) 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The relationship between Streptococcus pneumoniae isolates causing invasive infections in children admitted to a single center in central Israel was examined by pulsed-field gel electrophoresis (PFGE) and serotyping. Although there was a close correlation between serotype and PFGE clone, the genetic diversity varied by serotype, with some genotypes comprising multiple serotypes. Additionally, clones C and D were associated with higher penicillin minimum inhibitory concentrations. Serotyping alone may be insufficient for epidemiological mapping of pneumococcal isolates in the era of pneumococcal conjugate polysaccharide vaccines.

SUMMARY The incidence of invasive infections due to Neisseria meningitidis in Israel is about 1/100 000 population annually. Three cases of meningococcal meningitis were reported in employees at a single plant; the first case appeared in March 2013 and the second and third cases appeared in December, almost 9 months later. N. meningitidis serogroup B was isolated from cerebrospinal fluid samples. Multilocus sequence typing assigned the three meningococcal isolates to ST10418, a new sequence type and a member of the ST32 clonal complex. The clonality was confirmed by performance of pulsed-field gel electrophoresis. Post-exposure antibiotic prophylaxis was administered to close contacts of the first case. Upon the diagnosis of the additional two cases, post-exposure prophylaxis was administered to all the plant employees. This report demonstrates the importance of combining public health measures and advanced laboratory studies to confirm clonality and to prevent further disease spread in a closed setting.

ABSTRACT Salmonella enterica is the leading etiologic agent of bacterial food-borne outbreaks worldwide. This ubiquitous species contains more than 2,600 serovars that may differ in their host specificity, clinical manifestations, and epidemiology. To characterize salmonellosis epidemiology in Israel and to study the association of nontyphoidal Salmonella (NTS) serovars with invasive infections, 48,345 Salmonella cases reported and serotyped at the National Salmonella Reference Center between 1995 and 2012 were analyzed. A quasi-Poisson regression was used to identify irregular clusters of illness, and pulsed-field gel electrophoresis in conjunction with whole-genome sequencing was applied to molecularly characterize strains of interest. Three hundred twenty-nine human salmonellosis clusters were identified, representing an annual average of 23 (95% confidence interval [CI], 20 to 26) potential outbreaks. We show that the previously unsequenced S. enterica serovar 9,12:l,v:− belongs to the B clade of Salmonella enterica subspecies enterica, and we show its frequent association with extraintestinal infections, compared to other NTS serovars. Furthermore, we identified the dissemination of two prevalent Salmonella enterica serovar Typhimurium DT104 clones in Israel, which are genetically distinct from other global DT104 isolates. Accumulatively, these findings indicate a severe underreporting of Salmonella outbreaks in Israel and provide insights into the epidemiology and genomics of prevalent serovars, responsible for recurring illness.

ABSTRACT Salmonella enterica is the leading etiologic agent of bacterial food-borne outbreaks worldwide. This ubiquitous species contains more than 2,600 serovars that may differ in their host specificity, clinical manifestations, and epidemiology. To characterize salmonellosis epidemiology in Israel and to study the association of nontyphoidal Salmonella (NTS) serovars with invasive infections, 48,345 Salmonella cases reported and serotyped at the National Salmonella Reference Center between 1995 and 2012 were analyzed. A quasi-Poisson regression was used to identify irregular clusters of illness, and pulsed-field gel electrophoresis in conjunction with whole-genome sequencing was applied to molecularly characterize strains of interest. Three hundred twenty-nine human salmonellosis clusters were identified, representing an annual average of 23 (95% confidence interval [CI], 20 to 26) potential outbreaks. We show that the previously unsequenced S. enterica serovar 9,12:l,v:− belongs to the B clade of Salmonella enterica subspecies enterica, and we show its frequent association with extraintestinal infections, compared to other NTS serovars. Furthermore, we identified the dissemination of two prevalent Salmonella enterica serovar Typhimurium DT104 clones in Israel, which are genetically distinct from other global DT104 isolates. Accumulatively, these findings indicate a severe underreporting of Salmonella outbreaks in Israel and provide insights into the epidemiology and genomics of prevalent serovars, responsible for recurring illness.

National surveillance of Legionnaires' disease (LD) is important to inform control measures and facilitate international networking for timely reporting. This study is the first to describe the molecular epidemiology of LD in Israel. Case notifications for 2006-2011, collated through mandatory reporting, were identified and demographic, clinical and laboratory data were extracted. Unrelated clinical and environmental Legionella pneumophila strains were characterized using standard procedures, Dresden panel of monoclonal antibodies and the ESCMID Study Group for Legionella Infections (ESGLI) Sequence-Based Typing scheme. In all, 294 cases were reported (crude incidence 0.67 cases/100 000; age-standardized incidence 1/100 000). LD epidemiological trends and features largely resembled those of the EU, except for a larger proportion of nosocomial cases. Of 28 clinical and 23 environmental strains analysed, 71.4% and 21.7% were serogroup (sg) 1 and the most common immunological subgroup was OLDA/Oxford (64%). Of the clinical strains, OLDA/Oxford, ST1 was the most common (43%) followed by Allentown/France, ST40 (14%). The unusual sg 3 ST338 was found in 17.4% of environmental strains. Novel STs were detected amongst 23.5% of strains. These findings warrant further molecular investigation. Molecular epidemiology data generated from neighbouring countries newly adopting the ESGLI typing scheme for L. pneumophila contribute to understanding of regional strain diversity.

Following a bloodstream infection in June 2011 with Ralstonia mannitolilytica in a premature infant treated with a humidifying respiratory therapy device, an investigation was initiated at the Hadassah Medical Centres in Jerusalem. The device delivers a warmed and humidified mixture of air and oxygen to patients by nasal cannula. The investigation revealed colonisation with R. mannitolilytica of two of 15 patients and contamination of components of five of six devices deployed in the premature units of the Hadassah hospitals. Ten isolates from the investigation were highly related and indistinguishable from isolates described in an outbreak in 2005 in the United States (US). Measures successful in containing the US outbreak were not included in user instructions provided to our hospitals by the distributor of the device.

C Block (colinb@ekmd.huji.ac.il)1, Z Ergaz-Shaltiel2, L Valinsky3, V Temper1, C Hidalgo-Grass1, N Minster1, C Weissman4, S Benenson1, J Jaffe3, A E Moses1, B Bar-Oz2 1. Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel 2. Department of Neonatal Medicine, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel 3. Laboratory of Molecular Biology, Israel Ministry of Health, Jerusalem, Israel 4. Department of Anaesthesiology, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel

Streptococcus pyogenes group A (GAS) is a primary human pathogen. We performed genetic emm sequence and serological T-antigen typing of 819 mostly invasive GAS isolates recovered in Israel during 1996-2005. Of the 72 emm types found, the six most prevalent types (1, 81, 89, 14, 28, 5) comprised 30.2% of all isolates, and emm-type changes were observed over the years. The predicted coverage of the 26-valent S. pyogenes vaccine formulated for usage in the USA was predicted to be only approximately 60%. On the basis of different emm-T antigen type associations, some Israeli strains are probably different clonal types than those found in USA. About 2% of GAS had emm types that were originally associated with S. dysgalactiae subsp. equisimilis emm genes. Therefore, routine emm typing allows meaningful GAS strain surveillance, and provides data relevant to better vaccine coverage.

Between 1998 and 2007 the food-control laboratories in Israel tested 10,413 samples from five groups of RTE foods: salads/dips, dairy, fish, poultry and meat. A total of 1260 isolates of Listeria monocytogenes were identified and submitted to the reference listeria laboratory. The average isolation rate was 12.1% with the highest prevalence being registered in poultry (27%). The serological results showed the prevalence of Lineage I, followed by Lineages II and III. The report revealed a high isolation rate of L. monocytogenes in certain RTE foods in spite of the existing zero tolerance policy.

Neisseria meningitidis is an important cause of childhood meningitis and septicaemia. Between 1999 and 2005, 133 invasive meningococcal disease (IMD) cases occurred in Jerusalem, 112 (84.2%) of them in children aged 0-14 years. The annual incidence rate in Jerusalem was higher than the national average (2.45+/-0.6 vs. 1.13+/-0.16/100 000 population, P=0.002). Most of the children (82.1%) were from low socio-economic Arab and Jewish ultra-orthodox communities; mortality was higher among Arab than Jewish children (1.3 vs. 0.22/100 000 person-years, P=0.004). A cluster of 10 children with severe meningococcal sepsis (three fatalities) emerged in the winter of 2003-2004. Compared to the other 102 cases in 1999-2005 both meningococcaemia (100% vs. 51%, P=0.003) and mortality (30% vs. 6.9%, P=0.014) rates were higher. Serogroup B comprised 77.6% of the bacterial isolates. Pulsed-field gel electrophoresis showed considerable variability among cluster isolates, but significant resemblance in Arab cases throughout 1999-2005. The increased susceptibility of specific sub-populations to IMD necessitates further evaluation.

Routine susceptibility testing of 5,616 Shigella isolates at the National Shigella Reference Centre in Israel over a 5-year period (2000-2004) revealed resistance to ceftriaxone in one strain of Shigella boydii 2 and in two strains each of Shigella flexneri 2a, S. flexneri 6, and Shigella sonnei. All seven isolates were confirmed as producers of extended-spectrum beta-lactamase (ESBL) by the combination disk method, the Vitek 1 system, and a modification of the double-disk synergy test, which is based on the inhibitory properties of clavulanic acid, tazobactam, and sulbactam. Tazobactam had the strongest effect in all seven strains. Molecular characterization of the ESBLs identified CTX-M-type enzymes, consisting of the CTX-M-9 group (n = 3), CTX-M-3 (n = 2), CTX-M-39 (n = 1), and CTX-M-2 group (n = 1). Three of the strains also carried bla-(OXA) genes and a bla-(TEM) gene. Although the prevalence of ESBLs in this study was low, further research is needed on the spread and transfer of resistance genes, both in hospitals and in the community.

A seroepidemiological study was performed to evaluate immunity to diphtheria and to determine the correlates of diphtheria toxoid antibody levels among children and adults in Israel. In total, 3,185 sera from an age-stratified sample of children and adults, obtained in 2000-2001, were tested for diphtheria toxoid antibodies by an in-house double-antigen ELISA. A level of or=0.1 IU/mL (full protection or seropositivity). Seronegativity increased significantly in subjects aged >50 years, reaching levels of 9.7%, 12.6% and 18.9% in the groups aged 50-54, 55-59 and >60 years, respectively (p 0.001), with rates of basic immunity following a similar pattern. Subjects born abroad had higher seronegativity rates than those born in Israel (7.7% vs. 4.9%; p 0.019). No difference in diphtheria toxoid antibody levels was found according to other demographical variables, such as gender, Jewish or Arab ethnicity, urban or rural settlements, and the subjects' place of residence. The level of immunity to diphtheria among children and adults in Israel was satisfactory, with the exception of individuals aged >50 years. The risk of diphtheria outbreaks is low, but sporadic cases may occur among individuals lacking basic immunity against the disease.

This study outlines the unique epidemiology of Salmonella enterica serotype Virchow in Israel. Between 1997 and 2002, the overall incidence of non-typhoid Salmonella enterica (NTS) decreased from 69.3 to 53.3 infections/100,000 population, but the incidence of S. Virchow increased (from 7.2 to 9.1 infections/100,000). Since 2000, S. Virchow has become the second-ranking NTS isolate, accounting for 17% and 27% of all stool and blood NTS isolates, respectively. Infants aged < 1 year had the highest incidence of isolation from stools (92.8/100,000). The incidence of isolation from blood was highest for infants aged <1 year (4.4/100,000). Only 6% of isolates were susceptible to all ten antibiotic agents tested; 34% were resistant to one agent, 54% to one to three agents, and 40% to four to six agents. A high proportion of the tested isolates were resistant to nalidixic acid (89%), streptomycin (56%), tetracycline (43%), trimethoprim-sulphamethoxazole (38%) and chloramphenicol (28%), but none to ciprofloxacin or ceftriaxone. Pulsed-field gel electrophoresis revealed two closely related clusters, each containing a predominant pulsotype. Coupled with its invasive propensity, the increasing incidence of highly resistant S. Virchow in Israel is of real concern. Future research should focus on the sources of S. Virchow in the food chain in order to institute effective control measures.