BackgroundSpecies of the genus Aeromonas are native inhabitants of aquatic environments and have recently been considered emerging human pathogens. Although the gastrointestinal tract is by far the most common anatomic site from which aeromonads are recovered, their role as etiologic agents of bacterial diarrhea is still disputed. Aeromonas-associated diarrhea is a phenomenon occurring worldwide; however, the exact prevalence of Aeromonas infections on a global scale is unknown.Methodology/Principal FindingsThe prevalence and virulence potential of Aeromonas in patients suffering from diarrhea in Israel was studied using molecular methods. 1,033 diarrheal stools were sampled between April and September 2010 and Aeromonas species were identified in 17 (∼2%) patients by sequencing the rpoD gene. Aeromonas species identity and abundance was: A. caviae (65%), A. veronii (29%) and Aeromonas taiwanensis (6%). This is the first clinical record of A. taiwanensis as a diarrheal causative since its recent discovery from a wound infection in a patient in Taiwan. Most of the patients (77%) from which Aeromonas species were isolated were negative for any other pathogens. The patients ranged from 1 to 92 years in age. Aeromonas isolates were found to possess different virulence-associated genes: ahpB (88%), pla/lip/lipH3/apl-1 (71%), act/hlyA/aerA (35%), alt (18%), ast (6%), fla (65%), lafA (41%), TTSS ascV (12%), TTSS ascF-ascG (12%), TTSS-dependent ADP-ribosylating toxins aexU (41%) and aexT (6%) in various combinations. Most of the identified strains were resistant to beta-lactam antibiotics but susceptible to third-generation cephalosporin antibiotics.Conclusions Aeromonas may be a causative agent of diarrhea in patients in Israel and therefore should be included in routine bacteriological screenings.

The gene encoding the plant biosynthetic threonine deaminase (Td; EC 4.2.1.16) has been cloned as a result of its unusual upregulation in tomato flowers. The Td gene of tomato encodes a polypeptide of 595 residues, the first 80 of which comprise a putative two-domain transit peptide cleaved at position 51. Comparison of the amino acid sequence with the corresponding enzymes from yeast and bacteria reveals a near identity of the important catalytic regions and >40% overall similarity. The Td gene is unique in the tomato genome and its coding region is interrupted by eight introns. Its expression is >50-fold higher in sepals and >500-fold higher in the rest of the flower than in leaves or roots. Its overexpression, however, is strictly confined to the parenchymal cells of the floral organs. In young tomato leaves, the chloroplast-bound enzyme is found almost exclusively in the subepidermal spongy mesophyll cells.The biosynthetic and biodegradative threonine deaminase (Td) enzymes [L-threonine hydro-lyase (deaminating), EC 4.2.1.16] catalyze the conversion of L-threonine to a-ketobutyrate (1). The biosynthetic reaction is the first committed step of the pathway leading to the formation of the essential amino acid isoleucine. Regulation ofTd activity by isoleucine was the first example discovered of allosteric inhibition by the end product of a biosynthetic pathway. L-Threonine is also a feedback inhibitor of aspartate kinase and homoserine dehydrogenase, thus regulating the biosynthesis of threonine and other amino acids of the aspartate family (2, 3).The biosynthetic Td genes from Escherichia coli (ilvA) and yeast (ilvi) have been isolated and characterized (4-7). In plants, biosynthetic Td activity is associated with chloroplasts and the enzyme is feedback-regulated by isoleucine (8,9). Isoleucine-dependent Td-cell lines have been isolated from Nicotiana plumbaginifolia and shown to be complemented by ilvi from yeast (10, 11). The tomato Td reported here was cloned as a consequence of its unusual upregulation in floral organs. Flower development is initiated by a series of events that cause the irreversible conversion of a vegetative meristem to a floral meristem (12-14). As a working hypothesis it was proposed that upon induction, meristematic cells fated to form an inflorescence acquire a basic, cell-autonomous developmental program that distinguishes a floral cell from a vegetative cell (15). This distinction persists throughout floral development and is a prerequisite for the proper execution of homeotic transformations-i.e., organogenesis-as well as the ensuing organspecific gene activity. We have tried to approach the problem experimentally, by isolation of common regulatory elements of genes that are upregulated in all floral organs. Consequently, an extensive comparative study ofprotein profiles of leaves and flowers was undertaken. It was discovered that the gene encoding the most abundant protein of tomato flowers is, in fact, the structural gene for the tomato biosynthetic Td.t MATERIALS AND ME...

We provide an update on the epidemiology of shigellosis in Israel using data generated by a sentinel laboratory-based surveillance network for the period 1998-2012. The average annual incidence of culture-proven shigellosis was 97/100 000. We estimated that each case of shigellosis accounted for 25 cases in the community indicating the high burden of disease. Orthodox Jewish communities, living in highly crowded conditions and with a high number of children aged <5 years were the epicentre of country-wide biennial propagated epidemics of S. sonnei shigellosis. S. flexneri was the leading Shigella serogroup in Israeli Arabs. S. flexneri 2a and S. flexneri 6 alternated as the most common serotypes. Both S. sonnei and S. flexneri isolates showed high rates of resistance to ampicillin and trimethoprim/sulfamethoxazole and very low rates of resistance to quinolones and third-generation cephalosporins. Shigellosis due to S. sonnei conferred 81% (95% confidence interval 69-89) protection against the homologous Shigella serotype when epidemic exposure re-occurred 2 years later. These data are of value in the process of Shigella vaccine development.

The incidence of nontuberculous mycobacteria (NTM) infection among people with bronchiectasis varies between different geographical areas and accordingly between different series [1, 2]. Studies are largely based on bronchiectasis referral centres, which routinely screen for NTM in respiratory secretions. Therefore, the reported estimates of NTM prevalence in bronchiectasis may be exaggerated. Studies from bronchiectasis centres show conflicting results regarding risk factors for NTM: older age was found to increase risk in some but not other centres [1-4]. Due to the small numbers of patients in these studies, it is usually not possible to determine the effect of NTM infection on prognosis. Utilising the population registry of Israel's largest health maintenance organisation [5], we aimed to determine the incidence, risk factors and prognosis of NTM infection among patients with bronchiectasis. The database was searched for adults with bronchiectasis on January 1, 2010, excluding cystic fibrosis and idiopathic pulmonary fibrosis. We searched for laboratory codes indicating NTM between January 2010 and December 2016. We defined three categories of NTM. 1) "Growth": a single culture positive for any NTM. 2) "Colonisation": at least two cultures positive for the same NTM species. 3) "Treated": either of the above categories, treated with three or more antimycobacterial drugs. Medication use was determined from pharmacy reports. Socioeconomic status (SES) was based on the SES score of the clinic neighbourhood as defined by the Israeli Central Bureau of Statistics [6]. Mortality and hospitalisations during follow-up (2010-2016) were compared between patients with and without NTM infection. Multivariate logistic regression was used to identify the NTM risk factors. The Cox time dependent model was used to identify prognostic factors that influence hospitalisation and mortality. On January 1, 2010, the database included 2 710 432 adults. Of these, 6347 had a diagnosis of bronchiectasis (234 in 100 000). 6274 patients were without NTM infection prior to January 1. Of them, only 1871 (30%) patients had mycobacterial cultures available. In the general population (without bronchiectasis), 1476 (0.055%) people had NTM from respiratory specimens during follow up. Among people with bronchiectasis (n=6274), 105 (1.7%) grew NTM during follow-up. Only 30 (0.48%) cases had two or more cultures of the same NTM species, representing colonisation. Treatment with a combination of three or more antimycobacterial drugs was found in 12 (0.19%) patients. The incidence of NTM growth among all patients with bronchiectasis (n=6274) was estimated in four strata of age: 18-39, 40-59, 60-79 and ⩾80 years. The corresponding incidence of NTM growth were 1.1%, 2.2%, 1.9% and 0.9%, respectively (p=0.030). 50% of patients were 60-80 years old with a similar age distribution between patients with and without available mycobacterial cultures. Overall, 43% of patients with bronchiectasis in our study had emigrated from areas where tuberculosis is comm...

The aim of the present study was to assess the recent trends in the epidemiology of non-typhoid Salmonella in Israel using a sentinel laboratory-based surveillance network. Between 1999 and 2009, 8758 Salmonella stool isolates were reported by five sentinel laboratories. There was a significant decrease in the incidence rate of Salmonella isolates from 70·5/100,000 in 1999 to 21·6/100,000 in 2005 followed by a slight increase to 30·3/100,000 in 2009. Of all Salmonella, 64·3% were isolated from children in the 0-4 years age group. Up to 2008, S. Enteritidis was the most prevalent serotype and in 2009 S. Infantis emerged as the most common Salmonella serotype. The decrease in the incidence of S. Enteritidis and S. Typhimurium and increase in S. Infantis among humans were associated with a similar trend among breeding flocks, which followed significant preventive interventions conducted against S. Enteritidis and S. Typhimurium infections in poultry. Tight surveillance and education of food handlers and consumers should be enhanced to reduce the foodborne transmission of Salmonella in Israel.