Increase and diversity of carbapenemase-producing isolates, Italy.

This study reports on a surveillance in an Italian hospital focused on carbapenemase-producing (CP-Ec). Eighteen isolates (nine from clinical specimens and nine from rectal swab) were characterized for antibiotic susceptibilities, typing features, main carbapenemase, extended-spectrum ß-lactamases (ESBLs) and other genes, and their transferability by conjugation and transformation. An increase in CP-Ec isolates was observed during 3-year surveillance period.

Efficacy of carvacrol against resistant rapidly growing mycobacteria in the planktonic and biofilm growth mode.

Rapidly growing mycobacteria (RGM) are environmental bacteria found worldwide with a propensity to produce skin and soft-tissue infections. Among them, the most clinically relevant species is Mycobacterium abscessus. Multiple resistance to antibiotics and the ability to form biofilm contributes considerably to the treatment failure.

Chemical composition of Pistacia vera L. oleoresin and its antibacterial, anti-virulence and anti-biofilm activities against oral streptococci, including Streptococcus mutans.

Objective: The aim of this study was to characterize the chemical composition of oleoresin of Pistacia vera L. and to determine its antimicrobial and anti-virulence activity versus selected oral streptococci.

Design: A gaschromatografic analysis of the oleoresin was performed.

Attenuation of Virulence by L. Essential Oil.

Anti-virulence strategies are being explored as a novel approach to combat pathogens. Such strategies include inhibition of surface adhesion, tissue invasion, toxin production, and/or interference with the gene regulation of other virulence traits. , the causative agent of listeriosis, is a facultative intracellular food pathogen characterized by a wide distribution in the environment.

Breast milk oligosaccharides: effects of 2'-fucosyllactose and 6'-sialyllactose on the adhesion of and to Caco-2 cells.

It is well known that human milk oligosaccharides play an important role as prebiotics, anti-inflammatory, and anti-infective agents. In the last few years, several studies have been performed using specific oligosaccharides, such as 2'-fucosyllactose and 6'-sialylactose, to evaluate their biological functions. The aim of the present study is to evaluate the anti-adhesive effect of the above oligosaccharides on and .

Curcumin, an antibiotic resistance breaker against a multiresistant clinical isolate of Mycobacterium abscessus.

Curcumin, a phenolic compound extracted from Curcuma longa, exerts multiple pharmacological effects, including an antimicrobial action. Mycobacterium abscessus, an environmental, nontuberculous, rapidly growing mycobacterium, is an emerging human pathogen causing serious lung infections and one of the most difficult to treat, due to its multidrug resistance and biofilm-forming ability. We wanted to evaluate the antimicrobial and antivirulence activity of curcumin and its ability to synergize with antibiotics against a clinical M.

Identification, antimicrobial resistance and molecular characterization of the human emerging pathogen Streptococcus gallolyticus subsp. pasteurianus.

This study aimed to retrospectively identify 22Streptococcus bovis clinical strains based on the new taxonomy, as well as to investigate their antibiotic-resistance and clonality. Strains were identified by Phoenix100 system, 16S rRNA sequencing, and two MALDI-TOF MS platforms (Bruker Biotyper, Vitek MS). Antibiotic resistance was determined both phenotypically and genotypically, and clonality was assessed by PFGE.

Ongoing outbreak of invasive listeriosis due to serotype 1/2a Listeria monocytogenes, Ancona province, Italy, January 2015 to February 2016.

In the first seven weeks of 2016, five serotype 1/2a Listeria monocytogenes isolates were collected from patients with invasive listeriosis in Ancona province in Italy. These strains and six 1/2a isolates identified in 2015 in the same area were typed by ERIC-PCR and PFGE. A clonal relationship, documented between the two sets of isolates, suggested a listeriosis outbreak in Ancona that started most probably in 2015.

Human milk glycosaminoglycans inhibit in vitro the adhesion of Escherichia coli and Salmonella fyris to human intestinal cells.

Background: Breast-fed infants have a lower incidence of acute gastroenteritis due to the presence of several anti-infective factors in human milk. The aim of this work is to study the capacity of human milk glycosaminoglycans (GAGs) to inhibit the adhesion of some common pathogenic bacteria.

Methods: GAGs were isolated from a pool of milk samples collected from different mothers during the first month of lactation.

Antimicrobial and Anti-Virulence Activity of Capsaicin Against Erythromycin-Resistant, Cell-Invasive Group A Streptococci.

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the active component of Capsicum plants (chili peppers), which are grown as food and for medicinal purposes since ancient times, and is responsible for the pungency of their fruit. Besides its multiple pharmacological and physiological properties (pain relief, cancer prevention, and beneficial cardiovascular, and gastrointestinal effects) capsaicin has recently attracted considerable attention because of its antimicrobial and anti-virulence activity. This is the first study of its in vitro antibacterial and anti-virulence activity against Streptococcus pyogenes (Group A streptococci, GAS), a major human pathogen.

Recombination between Streptococcus suis ICESsu32457 and Streptococcus agalactiae ICESa2603 yields a hybrid ICE transferable to Streptococcus pyogenes.

Integrative conjugative elements (ICEs) are mobile genetic elements that reside in the chromosome but retain the ability to undergo excision and to transfer by conjugation. Genes involved in drug resistance, virulence, or niche adaptation are often found among backbone genes as cargo DNA. We recently characterized in Streptococcus suis an ICE (ICESsu32457) carrying resistance genes [tet(O/W/32/O), tet(40), erm(B), aphA, and aadE] in the 15K unstable genetic element, which is flanked by two ∼1.

Antimicrobial activity of essential oils and carvacrol, and synergy of carvacrol and erythromycin, against clinical, erythromycin-resistant Group A Streptococci.

In the present study, we have evaluated the in vitro antibacterial activity of essential oils from Origanum vulgare, Thymus vulgaris, Lavandula angustifolia, Mentha piperita, and Melaleuca alternifolia against 32 erythromycin-resistant [Mininum Inhibitory Concentration (MIC) ≥1 μg/mL; inducible, constitutive, and efflux-mediated resistance phenotype; erm(TR), erm(B), and mef(A) genes] and cell-invasive Group A streptococci (GAS) isolated from children with pharyngotonsillitis in Italy. Over the past decades erythromycin resistance in GAS has emerged in several countries; strains combining erythromycin resistance and cell invasiveness may escape β-lactams because of intracellular location and macrolides because of resistance, resulting in difficulty of eradication and recurrent pharyngitis. Thyme and origanum essential oils demonstrated the highest antimicrobial activity with MICs ranging from 256 to 512 μg/mL.

Adhesion of marine cryptic Escherichia isolates to human intestinal epithelial cells.

Five distinct cryptic lineages (clades I-V) have recently been recognized in the Escherichia genus. The five clades encompass strains that are phenotypically and taxonomically indistinguishable from Escherichia coli sensu stricto; however, scant data are available on their ecology, virulence and pathogenic properties. In this study 20 cryptic E.

Genetic diversity and virulence properties of Streptococcus dysgalactiae subsp. equisimilis from different sources.

A recent increase in virulence of pathogenic Streptococcus dysgalactiae subsp. equisimilis (SDSE) has been widely proposed. Such an increase may be partly explained by the acquisition of new virulence traits by horizontal gene transfer from related streptococci such as Streptococcus pyogenes (GAS) and Streptococcus agalactiae (GBS).

Dysbiosis contributes to fibrogenesis in the course of chronic liver injury in mice.

Unlabelled: Nonalcoholic fatty liver disease (NAFLD) may lead to hepatic fibrosis. Dietary habits affect gut microbiota composition, whereas endotoxins produced by Gram-negative bacteria stimulate hepatic fibrogenesis. However, the mechanisms of action and the potential effect of microbiota in the liver are still unknown.

Pitfalls encountered while investigating genetic elements by PCR.

The unprecedented wealth of databases that have become available in the era of next-generation sequencing has considerably increased our knowledge of bacterial genetic elements (GEs). At the same time, the advent of single-cell based approaches has brought realization that unsuspected heterogeneity may occur in the bacterial population from a single colony. The increasing use of PCR-based techniques to study new GEs requires careful consideration of the possible different PCR targets associated with different subpopulations if incorrect or incomplete interpretations are to be avoided.

Interspecies mobilization of an ermT-carrying plasmid of Streptococcus dysgalactiae subsp. equisimilis by a coresident ICE of the ICESa2603 family.

Objectives: The recently documented presence of almost identical, small, non-self-transmissible, erm(T)-carrying plasmids in clonally unrelated erythromycin-resistant isolates of Streptococcus pyogenes and Streptococcus agalactiae suggests that these plasmids somehow circulate in the streptococcal population. The objective of this study was to characterize the erm(T)-carrying genetic element in a clinical isolate of Streptococcus dysgalactiae subsp. equisimilis (Sde5580) and to provide a possible explanation for the spread of erm(T)-carrying plasmids in streptococci.

Characterization of a Streptococcus suis tet(O/W/32/O)-carrying element transferable to major streptococcal pathogens.

Mosaic tetracycline resistance determinants are a recently discovered class of hybrids of ribosomal protection tet genes. They may show different patterns of mosaicism, but their final size has remained unaltered. Initially thought to be confined to a small group of anaerobic bacteria, mosaic tet genes were then found to be widespread.

Streptococcus suis, an Emerging Drug-Resistant Animal and Human Pathogen.

Streptococcus suis, a major porcine pathogen, has been receiving growing attention not only for its role in severe and increasingly reported infections in humans, but also for its involvement in drug resistance. Recent studies and the analysis of sequenced genomes have been providing important insights into the S. suis resistome, and have resulted in the identification of resistance determinants for tetracyclines, macrolides, aminoglycosides, chloramphenicol, antifolate drugs, streptothricin, and cadmium salts.

Different genetic elements carrying the tet(W) gene in two human clinical isolates of Streptococcus suis.

The genetic support for tet(W), an emerging tetracycline resistance determinant, was studied in two strains of Streptococcus suis, SsCA and SsUD, both isolated in Italy from patients with meningitis. Two completely different tet(W)-carrying genetic elements, sharing only a tet(W)-containing segment barely larger than the gene, were found in the two strains. The one from strain SsCA was nontransferable, and aside from an erm(B)-containing insertion, it closely resembled a genomic island recently described in an S.

Genetic diversity of Streptococcus suis clinical isolates from pigs and humans in Italy (2003-2007).

Streptococcus suis, a major porcine pathogen, is emerging as a zoonotic agent capable of causing severe invasive disease in humans exposed to pigs or pork products. S. suis infection is rare in industrialised countries and usually arises as sporadic cases, with meningitis the most common clinical presentation in humans.

Lactobacillus rhamnosus GG inhibits invasion of cultured human respiratory cells by prtF1-positive macrolide-resistant group A streptococci.

Aims: This study was designed to determine whether the probiotic strain Lactobacillus GG, which is extensively used in the treatment and prevention of intestinal disorders, is able to inhibit invasion of cultured human respiratory cells by macrolide-resistant group A streptococci (GAS) carrying the prtF1 gene, which encodes the fibronectin (Fn)-binding invasin F1.

Methods And Results: Eight prtF1-positive erythromycin-resistant GAS strains were used to infect A549 monolayers in competition and displacement assays with Lactobacillus GG. Live (L-LGG) and heat-killed (HK-LGG) lactobacilli and their spent culture supernatant (SCS) significantly reduced (P < 0.