Treatment of Helicobacter pylori infection 14-day concomitant quadruple therapy versus triple therapy: A parallel double-blind randomized controlled trial.

Background and Aims: Successful Helicobacter pylori (Hp) eradication with the traditional 7-day course of proton pump inhibitor triple therapy is declining. Prolonging therapy to 14 days is associated with better eradication rates. Most learned societies recommend concomitant quadruple therapy (QC) as a first-line alternative therapy for this bacterial infection. The aim of this study is to compare the efficacy and safety of triple therapy (TT) and QC for the eradication of Hp infection. Methods: A parallel double-blind randomized controlled trial was conducted. The diagnosis of Hp infection was made by pathological examination of gastric biopsies. Patients were randomly assigned to two treatment groups: either QC (esomeprazole 80 mg, amoxicillin 2000 mg, clarithromycin 1000 mg, and metronidazole 1000 mg daily) or triple therapy (esomeprazole 80 mg, amoxicillin 2000 mg, and clarithromycin 1000 mg daily in divided doses) for 14 days. The efficacy of the treatment is defined by Hp eradication attested by a negative breath test performed 6 weeks after the completion of treatment. Treatment outcomes were compared using the chi-square test, while binary logistic regression identified predictors of treatment failure. Results: Ninety-two patients were included. Forty-two patients belonged to the QC group and 50 to the TT group. No significant difference was noted between the two groups concerning the rate of Hp eradication either by intention to treat (81% vs. 72% respectively, p = 0.31) or per protocol (81.6% vs. 76.1% respectively, p = 0.54). Likewise, there was no difference between the two groups in terms of tolerance to treatment (59.5% for QC vs. 58% for TT, p = 0.88). No factor has been associated with treatment failure. Conclusion: There was no significant difference in the rate of HP eradication between the QC and the 14-day triple therapy. Neither regimen should be used topically because of their low eradication rates.

Extensively drug-resistant Acinetobacter baumannii co-producing VIM-2 and OXA-23 in intensive care units: Results of a one-day point prevalence in a Tunisian hospital.

OBJECTIVE: The main objective of this study was to identify carbapenem resistance mechanisms among clinical, commensal and environmental carbapenem-resistant Acinetobacter baumannii (CRAB) strains isolated in 5 Tunisian intensive care units (ICUs). MATERIALS AND METHODS: CRAB isolates were recovered from different sources: clinical specimens, rectal and environmental swabs. Bacterial identification was carried out using conventional methods and susceptibility testing according to EUCAST recommendations. Evaluation of phenotypic carbapenemase production of was performed using seven different methods, and molecular detection of carbapenemase-coding genes (blaOXA23, blaOXA24, blaOXA58, blaNDM, blaGES, blaOXA48, blaIMP, blaVIM and blaKPC) was done by PCR. The genetic relationships between CRAB isolates were analyzed by pulsed-field gel electrophoresis. RESULTS: All in all, 46 CRAB isolates were identified in clinical specimens (n = 26/26), rectal swabs (n = 17/36) and environmental swabs (n = 3/63). Most of them (n = 41/46) were clonally related and found in the different ICUs. All of the CARB isolates harbored blaOXA-51-like and blaOXA-23 genes, while blaVIM-2 gene was detected in 42 isolates (91.3 %). Phenotypic carbapenemase activity was found in all 46 strains, using the CIM-Tris test with 100 % sensitivity for OXA-23 and VIM-carbapenemase detection, thereby justifying its routine use. CONCLUSION: The emergence and diffusion of clonal CRAB strains inducing high mortality rates in ICUs is a major public health concern. Enhanced infection control practices and mandatory staff education are needed to control the spread of these multidrug-resistant bacteria.

Antimicrobial activity and safety features assessment of Weissella spp. from environmental sources.

Weissella strains have been reported to be useful in biotechnological and probiotic determinations, and some of them are considered opportunistic pathogens. Given the widespread interest about antimicrobial susceptibilities, transmission of resistances, and virulence factors, there is little research available on such topics for Weissella. The aim of this study was to assess the safety aspects and antimicrobial potential of 54 Weissella spp. strains from different environmental sources. Antibiotic susceptibility, hemolytic activity, horizontal transfer, and antibacterial activity were studied, as well as the detection of biogenic amine BA production on decarboxylase medium and PCR was performed. All the strains were nonhemolytic and sensitive to chloramphenicol and ampicillin. Several strains were classified as resistant to fusidic acid, and very low resistance rates were detected to ciprofloxacin, tetracycline, streptomycin, lincomycin, erythromycin, and rifampicin, although all strains had intrinsic resistance to vancomycin, nalidixic acid, kanamycin, and teicoplanin. Two BA-producing strains (W. halotolerans FAS30 and FAS29) exhibited tyrosine decarboxylase activity, and just one W. confusa FS077 produced both tyramine and histamine, and their genetic determinants were identified. Ornithine decarboxylase/odc gene was found in 16 of the Weissella strains, although 3 of them synthesize putrescine. Interestingly, eight strains with good properties displayed antibacterial activity. Conjugation frequencies of erythromycin from Bacillus to Weissella spp. varied in the average of 3 × 10-9 transconjugants/recipient. However, no tetracycline-resistant transconjugant was obtained with Enterococcus faecalis JH2-2 as recipient. The obtained results support the safe status of Weissella strains, derived from environmental sources, when used as probiotics in animal feed.

Functional Probiotic Assessment and In Vivo Cholesterol-Lowering Efficacy of Weissella sp. Associated with Arid Lands Living-Hosts.

The research and the selection of novel probiotic strains from novel niches are receiving increased attention on their proclaimed health benefits to both humans and animals. This study aimed to evaluate the functional properties of Weissella strains from arid land living-hosts and to select strains with cholesterol-lowering property in vitro and in vivo, for use as probiotics. They were assessed for acid and bile tolerance, antibiotic susceptibility, membrane properties, antibacterial activity, antiadhesive effect against pathogens to host cell lines, and cholesterol assimilation in vitro. Our results showed that the majority of strains revealed resistance to gastrointestinal conditions. All the strains were nonhemolytic and sensitive to most of the tested antibiotics. They also exhibited high rates of autoaggregation and some of them showed high coaggregation with selected pathogens and high adhesion ability to two different cell lines (Caco-2 and MIM/PPk). Particularly, W. halotolerans F99, from camel feces, presented a broad antibacterial spectrum against pathogens, reduced Enterococcus faecalis and Escherichia coli adhesion to Caco-2 cells, and was found to reduce, in vitro, the cholesterol level by 49 %. Moreover, W. halotolerans F99 was evaluated for the carbohydrate utilization as well as the serum lipid metabolism effect in Wistar rats fed a high-cholesterol diet. W. halotolerans F99 showed an interesting growth on different plant-derivative oligosaccharides as sole carbon sources. Compared with rats fed a high-fat (HF) diet without Weissella administration, total serum cholesterol, low-density lipoprotein cholesterol, and triglycerides levels were significantly (p<0.001) reduced in W. halotolerans F99-treated HF rats, with no significant change in high-density lipoprotein cholesterol HDL-C levels. On the basis of these results, this is the first study to report that W. halotolerans F99, from camel feces, can be developed as cholesterol-reducing probiotic strain. Further studies may reveal their potential and possible biotechnological and probiotic applications.

First report of extensively-drug-resistant Proteus mirabilis isolate carrying plasmid-mediated blaNDM-1 in a Tunisian intensive care unit.

Emergence of the New Delhi metallo-ß-lactamase (NDM-1), an Ambler class B metallo-ß-lactamase able to hydrolyse all ß-lactams except monobactams, constitutes a critical and increasingly important medical issue. The acquisition of blaNDM-1 is of particular concern for Proteus mirabilis, which is intrinsically resistant to tetracycline, tigecycline and colistin, as this will make clinical treatment extremely difficult. To the authors' knowledge, this is the first report of the blaNDM-1 gene in an extensively-drug-resistant P. mirabilis clinical isolate carrying plasmid-mediated resistance to carbapenems (blaNDM-1), cephalosporins (blaCMY-4), aminoglycosides (aph3 VIa and aph3 Ia) and fluoroquinolones (qnrA6).

High Prevalence of Gut Microbiota Colonization with Broad-Spectrum Cephalosporin Resistant Enterobacteriaceae in a Tunisian Intensive Care Unit.

Healthcare-associated infections due to cefotaxime-resistant (CTX-R) Enterobacteriaceae have become a major public health threat, especially in intensive care units (ICUs). Often acquired nosocomially, CTX-R Enterobacteriaceae can be introduced initially by patients at admission. This study aimed to determine the prevalence and genetic characteristics of CTX-R Enterobacteriaceae-intestinal carriage in ICU patients, to evaluate the rate of acquisition of these organisms during hospitalization, and to explore some of the associated risk factors for both carriage and acquisition. Between December 2014 and February 2015, the 63 patients admitted in the ICU of Charles Nicolle hospital were screened for rectal CTX-R Enterobacteriaceae colonization at admission and once weekly thereafter to identify acquisition. CTX-R Enterobacteriaceae fecal carriage rate was 20.63% (13/63) at admission. Among the 50 non-carriers, 35 were resampled during their hospitalization and the acquisition rate was 42.85% (15/35). Overall, 35 CTX-R Enterobacteriaceae isolates were collected from 28 patients (25 Klebsiella pneumoniae, seven Escherichia coli, and three Enterobacter cloacae strains). Seven patients were simultaneously colonized with two CTX-R Enterobacteriaceae isolates. CTX-M-15 was detected in most of the CTX-R Enterobacteriaceae isolates (30/35, 88.23%). Three strains co-produced CMY-4 and 22 strains were carbapenem-resistant and co-produced a carbapenemase [OXA-48 (n = 13) or NDM-1 (n = 6)]. Molecular typing of K. pneumoniae strains, revealed eight Pulsed field gel electrophoresis (PFGE) patterns and four sequence types (ST) [ST101, ST147, ST429, and ST336]. However, E. coli isolates were genetically unrelated and belonged to A (n = 2), B1 (n = 2) and B2 (n = 3) phylogenetic groups and to ST131 (two strains), ST572 (two strains), ST615 (one strain) and ST617 (one strain). Five colonized patients were infected by CTX-R Enterobacteriaceae (four with the same strain identified from their rectal swab and one with a different strain). Whether imported or acquired during the stay in the ICU, colonization by CTX-R Enterobacteriaceae is a major risk factor for the occurrence of serious nosocomial infections. Their systematic screening in fecal carriage is mandatory to prevent the spread of these multidrug resistant bacteria.