The Challenge of Global Emergence of Novel Colistin-Resistant Escherichia coli ST131.

Escherichia coli ST131 is one of the high-risk multidrug-resistant clones with a global distribution and the ability to persist and colonize in a variety of niches. Carbapenemase-producing E. coli ST131 strains with the ability to resist last-line antibiotics (i.e., colistin) have been recently considered a significant public health. Colistin is widely used in veterinary medicine and therefore, colistin-resistant bacteria can be transmitted from livestock to humans through food. There are several mechanisms of resistance to colistin, which include chromosomal mutations and plasmid-transmitted mcr genes. E. coli ST131 is a great model organism to investigate the emergence of superbugs. This microorganism has the ability to cause intestinal and extraintestinal infections, and its accurate identification as well as its antibiotic resistance patterns are vitally important for a successful treatment strategy. Therefore, further studies are required to understand the evolution of this resistant organism for drug design, controlling the evolution of other nascent emerging pathogens, and developing antibiotic stewardship programs. In this review, we will discuss the importance of E. coli ST131, the mechanisms of resistance to colistin as the last-resort antibiotic against resistant Gram-negative bacteria, reports from different regions regarding E. coli ST131 resistance to colistin, and the most recent therapeutic approaches against colistin-resistance bacteria.

LACTB suppresses melanoma progression by attenuating PP1A and YAP interaction.

Very limited progress has been made in the management of advanced melanoma, especially melanoma of uveal origin. Lactamase ß (LACTB) is a novel tumor suppressor; however, its biological function in melanoma remains unknown. Herein we demonstrated markedly lower LACTB expression levels in melanoma tissues and cell lines. Overexpression of LACTB suppressed the proliferation, migration and invasion of melanoma cells in vitro. Mechanistically, LACTB inhibited the activity of yes-associated protein (YAP). We showed that the level of phospho-YAP (Serine 127) was increased upon LACTB overexpression, which prevented the translocation of YAP to the nucleus. Further, LACTB could directly bind to PP1A and attenuate the interaction between PP1A and YAP, resulting in decreased YAP dephosphorylation and inactivation in a LATS1-independent manner. Additionally, transfection of phosphorylation-defective YAP mutants reversed LACTB-induced tumor suppression. Upstream, we demonstrated that SOX10 binds to the LACTB promoter and negatively regulates its transcription. Overexpression of LACTB also suppressed the tumorigenicity and lung metastasis of MUM2B uveal melanoma cells in vivo. Taken together, our findings indicate a novel SOX10/LACTB/PP1A signaling cascade that renders YAP inactive and modulates melanoma progression, offering a new therapeutic target for melanoma treatment.

ß-lactamase-mediated resistance in MDR-Pseudomonas aeruginosa from Qatar.

BACKGROUND: The distribution of ß-lactam resistance genes in P. aeruginosa is often closely related to the distribution of certain high-risk international clones. We used whole-genome sequencing (WGS) to identify the predominant sequence types (ST) and ß-lactamase genes in clinical isolates of multidrug-resistant (MDR)-P. aeruginosa from Qatar METHODS: Microbiological identification and susceptibility tests were performed by automated BD Phoenix™ system and manual Liofilchem MIC Test Strips. RESULTS: Among 75 MDR-P. aeruginosa isolates; the largest proportions of susceptibility were to ceftazidime-avibactam (n = 36, 48%), followed by ceftolozane-tazobactam (30, 40%), ceftazidime (n = 21, 28%) and aztreonam (n = 16, 21.3%). All isolates possessed Class C and/or Class D ß-lactamases (n = 72, 96% each), while metallo-ß-lactamases were detected in 20 (26.7%) isolates. Eight (40%) metallo-ß-lactamase producers were susceptible to aztreonam and did not produce any concomitant extended-spectrum ß-lactamases. High risk ST235 (n = 16, 21.3%), ST357 (n = 8, 10.7%), ST389 and ST1284 (6, 8% each) were most frequent. Nearly all ST235 isolates (15/16; 93.8%) were resistant to all tested ß-lactams. CONCLUSION: MDR-P. aeruginosa isolates from Qatar are highly resistant to antipseudomonal ß-lactams. High-risk STs are predominant in Qatar and their associated MDR phenotypes are a cause for considerable concern.

First detected OXA-50 carbapenem-resistant clinical isolates Pseudomonas aeruginosa from Bulgaria and interplay between the expression of main efflux pumps, OprD and intrinsic AmpC.

Introduction. Carbapenems are often described as the most effective weapon against infections caused by multidrug-resistant bacteria especially those belonging to the group of non-fermenting bacteria such as Pseudomonas. The main mechanisms leading to resistance are the hyperexpression of certain efflux pumps belonging to the resisto-nodular division and the lower expression of the transmembrane porin OprD, sometimes in combination with excessive production of the intrinsic AmpC. Carbapenemases are assumed to play a secondary role.Aim. The aim of this study was to determine the exact mechanisms of carbapenem resistance in Pseudomonas aeruginosa isolates from the largest Bulgarian University hospital 'St. George'- Plovdiv.Methodology. A total of 32 clinical isolates collected from different patients' samples resistant to imipenem and/or meropenem were examined via phenotypic and molecular-genetic tests.Results. No metallo-enzyme production was detected. Three isolates were positive for OXA-50-encoding genes in two of them in combination with other oxacillinases or the bla VEB-1 gene. For the first time, OXA-50-producing P. aeruginosa have been reported in Bulgaria. The increased expression or hyperexpression of MexXY-OprM efflux pump was observed as the main mechanism of resistance. In most cases, it was combined with lower expression or lack of OprD with or without MexAB-OprM hyperexpression. No excessive production of AmpC was detected in comparison to the reference ATCC 27853 P. aeruginosa strain.Conclusion. The increased expression or overexpression of MexXY-OprM efflux pumps is the leading cause of carbapenem resistance in our isolates Pseudomonas, detected in 94 % of the bacteria investigated.

"It Takes a Village": Mechanisms Underlying Antimicrobial Recalcitrance of Polymicrobial Biofilms.

Chronic infections are frequently caused by polymicrobial biofilms. Importantly, these infections are often difficult to treat effectively in part due to the recalcitrance of biofilms to antimicrobial therapy. Emerging evidence suggests that polymicrobial interactions can lead to dramatic and unexpected changes in the ability of antibiotics to eradicate biofilms and often result in decreased antimicrobial efficacy in vitro In this review, we discuss the influence of polymicrobial interactions on the antibiotic susceptibility of biofilms, and we highlight the studies that first documented the shifted antimicrobial susceptibilities of mixed-species cultures. Recent studies have identified several mechanisms underlying the recalcitrance of polymicrobial biofilm communities, including interspecies exchange of antibiotic resistance genes, ß-lactamase-mediated inactivation of antibiotics, changes in gene expression induced by metabolites and quorum sensing signals, inhibition of the electron transport chain, and changes in properties of the cell membrane. In addition to elucidating multiple mechanisms that contribute to the altered drug susceptibility of polymicrobial biofilms, these studies have uncovered novel ways in which polymicrobial interactions can impact microbial physiology. The diversity of findings discussed highlights the importance of continuing to investigate the efficacy of antibiotics against biofilm communities composed of different combinations of microbial species. Together, the data presented here illustrate the importance of studying microbes as part of mixed-species communities rather than in isolation. In light of our greater understanding of how interspecies interactions alter the efficacy of antimicrobial agents, we propose that the methods for measuring the drug susceptibility of polymicrobial infections should be revisited.

Role of outer membrane permeability, efflux mechanism, and carbapenemases in carbapenem-nonsusceptible Pseudomonas aeruginosa from Dubai hospitals: Results of the first cross-sectional survey.

OBJECTIVES: Carbapenem resistance in Pseudomonas aeruginosa is growing and results from variable mechanisms. The objectives of the current study were to investigate mechanisms of carbapenem resistance and genetic relatedness of P. aeruginosa isolates recovered in Dubai hospitals. METHODS: From June 2015 through June 2016, carbapenem-nonsusceptible P. aeruginosa were collected from 4 hospitals in Dubai, and subjected to antimicrobial susceptibility testing, molecular investigation of carbapenemases by PCR-sequencing, analysis of outer membrane porin OprD2 and multidrug efflux channel MexAB-OprM levels by qPCR, and fingerprinting by ERIC-PCR. RESULTS: Out of 1969 P. aeruginosa isolated during the study period, 471 (23.9%) showed reduced carbapenem susceptibility. Of these, 37 were analyzed and 32% of them produced VIM-type metallo-ß-lactamases, including VIM-2, VIM-30, VIM-31, and VIM-42, while GES-5 and GES-9 co-existed with VIM in 5.4% of isolates. Outer membrane impermeability was observed in 73% of isolates and 75.6% displayed overproduced MexAB-OprM. ERIC-PCR revealed one large clone including most carbapenemase-producing isolates indicating clonal dissemination. CONCLUSION: This is the first study on carbapenem-nonsusceptible P. aeruginosa from Dubai, incriminating VIM production as well as outer membrane permeability and efflux systems as resistance mechanisms. Further studies on carbapenem-nonsusceptible P. aeruginosa in Dubai are warranted for containment of such health hazard.

Recombinant Treponema pallidum protein Tp47 promotes the migration and adherence of THP-1 cells to human dermal vascular smooth muscle cells by inducing MCP-1 and ICAM-1 expression.

Vascular inflammation is a complex and multifactorial pathophysiological process that plays a crucial role in all stages of syphilis and is responsible for tissue damage. Little is known about the interactions of infiltrating immunocytes with human dermal vascular smooth muscle cells (HDVSMCs) in arterioles during the immunopathogenesis of syphilis. The Treponema pallidum subsp. pallidum membrane protein Tp47 is considered a major inducer of inflammation initiation and development. In this study, we demonstrated that Tp47 promoted the migration and adhesion of THP-1 cells to HDVSMCs. Furthermore, Tp47 increased monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) mRNA and protein expression levels in a dose- and time-dependent manner. The migration and adhesion of THP-1 cells to HDVSMCs were significantly suppressed by anti-MCP-1 and anti-ICAM-1 neutralizing antibodies, respectively. Further studies revealed that treatment of HDVSMCs with Tp47 activated the PI3K/Akt, p38 MAPK and NF-κB signalling pathways. Inhibition of PI3K/Akt, p38 MAPK and NF-κB suppressed the MCP-1 and ICAM-1 expression induced by Tp47. In addition, the migration and adhesion of THP-1 cells to Tp47-treated HDVSMCs were significantly decreased by pretreatment with PI3K/Akt, p38 MAPK and NF-κB inhibitors. These findings demonstrate that Tp47 promotes the migration and adherence of THP-1 cells to HDVSMCs by inducing MCP-1 and ICAM-1 expression, which is mediated by activation of the PI3K/Akt, p38 MAPK and NF-κB pathways. This study provides a novel potential therapeutic strategy for controlling the vascular inflammatory response in syphilis patients.

Carbapenemases: The never-ending story / Carbapenemasas: la historia interminable

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An active ß-lactamase is a part of an orchestrated cell wall stress resistance network of Bacillus subtilis and related rhizosphere species.

A hallmark of the Gram-positive bacteria, such as the soil-dwelling bacterium Bacillus subtilis, is their cell wall. Here, we report that d-leucine and flavomycin, biofilm inhibitors targeting the cell wall, activate the ß-lactamase PenP. This ß-lactamase contributes to ampicillin resistance in B. subtilis under all conditions tested. In contrast, both Spo0A, a master regulator of nutritional stress, and the general cell wall stress response, differentially contribute to ß-lactam resistance under different conditions. To test whether ß-lactam resistance and ß-lactamase genes are widespread in other Bacilli, we isolated Bacillus species from undisturbed soils, and found that their genomes can encode up to five ß-lactamases with differentiated activity spectra. Surprisingly, the activity of environmental ß-lactamases and PenP, as well as the general stress response, resulted in a similarly reduced lag phase of the culture in the presence of ß-lactam antibiotics, with little or no impact on the logarithmic growth rate. The length of the lag phase may determine the outcome of the competition between ß-lactams and ß-lactamases producers. Overall, our work suggests that antibiotic resistance genes in B. subtilis and related species are ancient and widespread, and could be selected by interspecies competition in undisturbed soils.

Pseudomonas Aeruginosa: Virulence Factors and Antibiotic Resistance Genes

Abstract In this review, we explore some aspects of Pseudomonas aeruginosa virulence factors that are related to disease development in healthy organisms and resistance to antibiotics. This pathogen is one of the most clinically and epidemiologically important bacteria in Brazil, being the major cause of opportunistic infections. Among the virulence factors, biofilm formation acting of manner different in the organism. Furthermore, we review several P. aeruginosa genes that act in antimicrobial resistance, such as β-lactamases against β-lactamers. The resistance to pied-lactamases in P. aeruginosa is associated to resistance to the broad-spectrum cephalosporin. On the other hand, there is a group of synthetic broad-spectrum antibiotics acting on DNA synthesis is the quinolones that destroy the microorganism. We also explore the occurence of super bacterium: P. aerufinosa carrying genes blaKPC and blaNDM, which are associated with patient death above the average of other bacterial infections in hospitals. Those genes encode carbapenemases that can potentially hydrolyse all β-lactam antibiotics

Molecular detection of blaVIM Metallo-ß-lactamase producing clinically isolated Pseudomonas aeruginosa from tertiary care hospital, Faisalabad.

Metallo-ß-lactamases (MBLs) producing Pseudomonas aeruginosa are major threat for public health. They produce resistance against various antibiotics and remain low or no therapeutic options. A total of 200 clinical isolates of P. aeruginosa were collected from tertiary care hospital, Faisalabad. Isolates were sub-cultured on basic and selective media and confirmed by API 20NE. Phenotypic detection of carbapenamase, MBLs, antibiogram and MIC were determined as per CLSI guidelines. Molecular detection of blaVIM was performed using specific primers by PCR. Among 200 P. aeruginosa, majority (n=82) were isolated from pus samples followed by 28 from tracheal aspirates and 27 from sputum. Out of 110 (55%) MDR P. aeruginosa, 12 (11%) were positive for MHT and MBLs and blaVIM was identified in MBL positive isolates. Antibiogram revealed that all the isolates were resistant to ß-lactam drugs including carbapenems followed by 95% to levofloxacin, 67% to doxycycline and more effective drugs were tigecycline and colistin. MIC value for imipenem drug was 16µg/mL and 8µg/mL against 6 and 5 isolates respectively while MIC value for meropenem against 6 and 3 isolates were 8µg/mL and 16µg/mL respectively. Our study concluded the high prevalence of blaVIM producing P. aeruginosa in our clinical settings.

Determination of antibiotic resistance pattern and prevalence of OXA-type carbapenemases among Acinetobacter baumannii clinical isolates from inpatients in Isfahan, central Iran.

Acinetobacter baumannii is one of the most important bacterial species with the ability to produce OXA-type carbapenemases. We aimed to evaluate the prevalence of OXA-type carbapenemases among clinical isolates of A. baumannii in three major hospitals of Isfahan. In this cross-sectional descriptive study, 153 non-repeated strains of A. baumannii were isolated from various clinical samples of hospitalized patients in Al-Zahra, Imam Mousa Kazem, and Shariati hospitals from October 2015 to October 2016. Antimicrobial susceptibility testing for imipenem, meropenem, ertapenem, cefepime, ceftazidime, ceftriaxone, piperacillin-tazobactam, gentamicin, amikacin, ciprofloxacin, and tetracycline was performed using the disk diffusion method. In order to identify bla-oxa genes, a multiplex polymerase chain reaction was used. The resistance rates in A. baumannii isolates to beta-lactam antibiotics including imipenem, ertapenem, meropenem, cefepime, ceftazidime, ceftriaxone, and piperacillin/tazobactam were 100%, 100%, 99.3%, 97.4%, 96.7%, 97.4%, and 98.6%, respectively. PCR assay showed the presence of bla-oxa genes in all isolates. The bla-oxa-51 gene was recognized in all (100%) isolates, 90.8% and 62.1% of isolates possessed the bla-oxa-23 and bla-oxa-24 genes, respectively, while the bla-oxa-58 gene was not detected in any of the isolates. Also, 56.2% of isolates had both the bla-oxa-23 and bla-oxa-24 genes simultaneously. We found that the prevalence of OXA-type carbapenemases among carbapenem-resistant A. baumannii isolates is high in Isfahan, with OXA-23 being the major carbapenemase mechanism responsible for the resistance phenotype.

Multirresistencia y factores asociados a la presencia de betalactamasas de espectro extendido en cepas de Escherichia coli provenientes de urocultivos / Multiresistance and factors associated with the presence of extended-spectrum beta-lactamases in Escherichia coli strains isolated from urine culture

RESUMEN El tratamiento empírico para la infección urinaria se ve complicado frente a la presencia de multirresistencia y de betalactamasas de espectro extendido (BLEE). El objetivo del estudio fue describir los patrones de resistencia antibiótica de cepas de Escherichia coli aisladas en urocultivos y los factores clínico-epidemiológicos asociados a la presencia de BLEE en un grupo pediátrico y adulto. Se recolectaron durante 14 meses, 353 cepas provenientes de Emergencia y Hospitalización del Hospital Cayetano Heredia, 45,9% fueron cepas multirresistentes. La incidencia de BLEE en población pediátrica fue 16,3% vs. 31,1% en la adulta, el 63,6% provenía de pacientes ambulatorios. La presencia de BLEE se asoció con encontrarse hospitalizado en pediatría, así cómo al uso de pañal y vejiga neurogénica en adultos. Estos factores deben considerarse al momento de elegir un tratamiento antibiótico. Asimismo, es necesario implementar programas de reporte epidemiológico y modelos de prevención de factores de riesgo.

ABSTRACT The empirical treatment of urinary infections is complicated by the presence of multiresistance and resistance to extendedspectrum beta-lactamases (ESBLs). The objective of this study was to describe the patterns of antibiotic resistance of Escherichia coli strains isolated from urine cultures and the clinical-epidemiological factors associated with the presence of ESBLs in a pediatric and an adult group. A total of 353 strains were collected from the Emergency and Hospitalization Sector of the Cayetano Heredia Hospital over 14 months, and 45.9% of the isolated strains were multiresistant. The rate of resistance to ESBLs in the pediatric and adult population was 16.3% and 31.1%, respectively, and 63.6% of the resistant strains were isolated from outpatients. The presence of ESBLs was associated with hospitalization in pediatrics, use of diapers, and the presence of neurogenic bladder in adults. These factors should be considered in selection of an antibiotic treatment. Moreover, epidemiological reporting programs and models should be implemented for reduction of risk factors.

Role of Low-Molecular-Mass Penicillin-Binding Proteins, NagZ and AmpR in AmpC ß-lactamase Regulation of Yersinia enterocolitica.

Yersinia enterocolitica encodes a chromosomal AmpC ß-lactamase under the regulation of the classical ampR-ampC system. To obtain a further understanding to the role of low-molecular-mass penicillin-binding proteins (LMM PBPs) including PBP4, PBP5, PBP6, and PBP7, as well as NagZ and AmpR in ampC regulation of Y. enterocolitica, series of single/multiple mutant strains were systematically constructed and the ampC expression levels were determined by luxCDABE reporter system, reverse transcription-PCR (RT-PCR) and ß-lactamase activity test. Sequential deletion of PBP5 and other LMM PBPs result in a continuously growing of ampC expression level, the ß-lactamse activity of quadruple deletion strain YEΔ4Δ5Δ6Δ7 (pbp4, pbp5, pbp6, and pbp7 inactivated) is approached to the YEΔD123 (ampD1, ampD2, and ampD3 inactivated). Deletion of nagZ gene caused two completely different results in YEΔD123 and YEΔ4Δ5Δ6Δ7, NagZ is indispensable for YEΔ4Δ5Δ6Δ7 ampC derepression phenotype but dispensable for YEΔD123. AmpR is essential for ampC hyperproduction in these two types of strains, inactivation of AmpR notable reduced the ampC expression level in both YEΔD123 and YEΔ4Δ5Δ6Δ7.

Clinical Variants of New Delhi Metallo-ß-Lactamase Are Evolving To Overcome Zinc Scarcity.

Use and misuse of antibiotics have driven the evolution of serine ß-lactamases to better recognize new generations of ß-lactam drugs, but the selective pressures driving evolution of metallo-ß-lactamases are less clear. Here, we present evidence that New Delhi metallo-ß-lactamase (NDM) is evolving to overcome the selective pressure of zinc(II) scarcity. Studies of NDM-1, NDM-4 (M154L), and NDM-12 (M154L, G222D) demonstrate that the point mutant M154L, contained in 50% of clinical NDM variants, selectively enhances resistance to the penam ampicillin at low zinc(II) concentrations relevant to infection sites. Each of the clinical variants is shown to be progressively more thermostable and to bind zinc(II) more tightly than NDM-1, but a selective enhancement of penam turnover at low zinc(II) concentrations indicates that most of the improvement derives from catalysis rather than stability. X-ray crystallography of NDM-4 and NDM-12, as well as bioinorganic spectroscopy of dizinc(II), zinc(II)/cobalt(II), and dicobalt(II) metalloforms probe the mechanism of enhanced resistance and reveal perturbations of the dinuclear metal cluster that underlie improved catalysis. These studies support the proposal that zinc(II) scarcity, rather than changes in antibiotic structure, is driving the evolution of new NDM variants in clinical settings.

[Multiresistance and factors associated with the presence of extended-spectrum beta-lactamases in Escherichia coli strains isolated from urine culture]. / Multirresistencia y factores asociados a la presencia de betalactamasas de espectro extendido en cepas de Escherichia coli provenientes de urocultivos.

The empirical treatment of urinary infections is complicated by the presence of multiresistance and resistance to extendedspectrum beta-lactamases (ESBLs). The objective of this study was to describe the patterns of antibiotic resistance of Escherichia coli strains isolated from urine cultures and the clinical-epidemiological factors associated with the presence of ESBLs in a pediatric and an adult group. A total of 353 strains were collected from the Emergency and Hospitalization Sector of the Cayetano Heredia Hospital over 14 months, and 45.9% of the isolated strains were multiresistant. The rate of resistance to ESBLs in the pediatric and adult population was 16.3% and 31.1%, respectively, and 63.6% of the resistant strains were isolated from outpatients. The presence of ESBLs was associated with hospitalization in pediatrics, use of diapers, and the presence of neurogenic bladder in adults. These factors should be considered in selection of an antibiotic treatment. Moreover, epidemiological reporting programs and models should be implemented for reduction of risk factors.

El tratamiento empírico para la infección urinaria se ve complicado frente a la presencia de multirresistencia y de betalactamasas de espectro extendido (BLEE). El objetivo del estudio fue describir los patrones de resistencia antibiótica de cepas de Escherichia coli aisladas en urocultivos y los factores clínico-epidemiológicos asociados a la presencia de BLEE en un grupo pediátrico y adulto. Se recolectaron durante 14 meses, 353 cepas provenientes de Emergencia y Hospitalización del Hospital Cayetano Heredia, 45,9% fueron cepas multirresistentes. La incidencia de BLEE en población pediátrica fue 16,3% vs. 31,1% en la adulta, el 63,6% provenía de pacientes ambulatorios. La presencia de BLEE se asoció con encontrarse hospitalizado en pediatría, así cómo al uso de pañal y vejiga neurogénica en adultos. Estos factores deben considerarse al momento de elegir un tratamiento antibiótico. Asimismo, es necesario implementar programas de reporte epidemiológico y modelos de prevención de factores de riesgo.

GRY79 encoding a putative metallo-ß-lactamase-trihelix chimera is involved in chloroplast development at early seedling stage of rice.

KEY MESSAGE: The green - revertible yellow79 mutant resulting from a single-base mutation suggested that the GRY79 gene encoding a putative metallo-ß-lactamase-trihelix chimera is involved in chloroplast development at early seedling stage of rice. Functional studies of metallo-ß-lactamases and trihelix transcription factors in higher plants remain very sparse. In this study, we isolated the green-revertible yellow79 (gry79) mutant in rice. The mutant developed yellow-green leaves before the three-leaf stage but recovered to normal green at the sixth-leaf stage. Meanwhile, the mutant exhibited reduced level of chlorophylls and arrested development of chloroplasts in the yellow leaves. Genetic analysis suggested that the mutant phenotype was controlled by a single recessive nuclear gene on rice chromosome 2. Map-based cloning revealed that the candidate gene was Os02g33610 encoding a putative metallo-ß-lactamase-trihelix chimera. In the gry79 mutant, a single-base mutation occurred in coding region of the gene, resulting in an amino acid change in the encoded protein. Furthermore, the mutant phenotype was rescued by transformation with the wild-type gene. Therefore, we have confirmed that the gry79 mutant phenotype resulted from a single-base mutation in GRY79 (Os02g33610) gene, suggesting that the gene encoding a putative metallo-ß-lactamase-trihelix chimera is involved in chloroplast development at early seedling stage of rice. In addition, we considered that the gry79 mutant gene could be applicable as a leaf-color marker gene for efficient identification and elimination of false hybrids in commercial hybrid rice production.

Non-carbapenem therapy of urinary tract infections caused by extended-spectrum ß-lactamase-producing Enterobacteriaceae.

PURPOSE: We determined the prevalence of ESBL Enterobacteriaceae in urinary tract infections among inpatients, identified risk factors of acquisition, and evaluated the effectiveness of alternatives to carbapenems. METHODS: The clinical, microbiological, and therapeutic data as well as the outcomes were recorded for all ESBL-E positive urine samples for three months. RESULTS: Thirty-one (4%) of the 762 Enterobacteriaceae positive cultures were ESBL producers. The predisposing conditions for being infected with those strains were: immunodepression (61%), recent hospitalization (52%), recent antibiotic therapy (52%), and urinary catheterization (61%). 19% of infections were community acquired. The seven cases of acute pyelonephritis and five of prostatitis were treated with piperacillin-tazobactam (5), fluoroquinolones (4), ceftazidime (2), or carbapenems (only 1) after specialized advice. Four (33%) patients relapsed at week 10: three were immunodepressed and three presented with bacteremia. CONCLUSIONS: Alternatives to carbapenems (especially piperacillin-tazobactam) seem to be a good option for non-bacteremic UTI in immunocompetent patients.