Genomic context as well as sequence of both and penicillin-binding protein 5 contributes to β-lactam resistance in .

Unlabelled: Penicillin-binding protein 5 (PBP5) of () is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in clade B strains [ampicillin susceptible (AMP-S)], PBP5-S/R (AMP-S or R), and PBP5-R (AMP-R) in clade A strains. Here, deletion resulted in a marked reduction in AMP minimum inhibitory concentrations (MICs) to 0.

Enterococcus faecium Clade Competition in the Presence of β-Lactam Antibiotics in a Mouse GI Tract Colonization Model.

Previously, we showed that Enterococcus faecium clade B strains outcompeted health care-associated clade A1 strains in murine gastrointestinal colonization. Here, parenterally administered piperacillin-tazobactam and ceftriaxone significantly promoted colonization by clade A1 over clade B strains except that ceftriaxone, at the dose used, did not favor the least β-lactam-resistant A1 strain. The advantage that β-lactam administration gives to more highly ampicillin-resistant E.

Drinking water chlorination has minor effects on the intestinal flora and resistomes of Bangladeshi children.

Healthy development of the gut microbiome provides long-term health benefits. Children raised in countries with high infectious disease burdens are frequently exposed to diarrhoeal pathogens and antibiotics, which perturb gut microbiome assembly. A recent cluster-randomized trial leveraging >4,000 child observations in Dhaka, Bangladesh, found that automated water chlorination of shared taps effectively reduced child diarrhoea and antibiotic use.

Urban informal settlements as hotspots of antimicrobial resistance and the need to curb environmental transmission.

Antimicrobial resistance (AMR) is a growing public health challenge that is expected to disproportionately burden lower- and middle-income countries (LMICs) in the coming decades. Although the contributions of human and veterinary antibiotic misuse to this crisis are well-recognized, environmental transmission (via water, soil or food contaminated with human and animal faeces) has been given less attention as a global driver of AMR, especially in urban informal settlements in LMICs-commonly known as 'shanty towns' or 'slums'. These settlements may be unique hotspots for environmental AMR transmission given: (1) the high density of humans, livestock and vermin living in close proximity; (2) frequent antibiotic misuse; and (3) insufficient drinking water, drainage and sanitation infrastructure.

Digital multiplex ligation assay for highly multiplexed screening of β-lactamase-encoding genes in bacterial isolates.

Increasing incidence of antibiotic resistance in clinical and environmental settings calls for increased scalability in their surveillance. Current screening technologies are limited by the number of samples and genes that can easily be screened. We demonstrate here digital multiplex ligation assay (dMLA) as a low-cost targeted genomic detection workflow capable of highly-parallel screening of bacterial isolates for multiple target gene regions simultaneously.

High Genomic Diversity and Heterogenous Origins of Pathogenic and Antibiotic-Resistant Escherichia coli in Household Settings Represent a Challenge to Reducing Transmission in Low-Income Settings.

is present in multiple hosts and environmental compartments as a normal inhabitant, temporary or persistent colonizer, and as a pathogen. Transmission of between hosts and with the environment is considered to occur more often in areas with poor sanitation. We performed whole-genome comparative analyses on 60 isolates from soils and fecal sources (cattle, chickens, and humans) in households in rural Bangladesh.

Risk Factors for Detection, Survival, and Growth of Antibiotic-Resistant and Pathogenic Escherichia coli in Household Soils in Rural Bangladesh.

Soils in household environments in low- and middle-income countries may play an important role in the persistence, proliferation, and transmission of Our goal was to investigate the risk factors for detection, survival, and growth of in soils collected from household plots. was enumerated in soil and fecal samples from humans, chickens, and cattle from 52 households in rural Bangladesh. Associations between concentrations in soil, household-level risk factors, and soil physicochemical characteristics were investigated.

Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors.

pathotypes (i.e., enteropathogenic and enterotoxigenic) have been identified among the pathogens most responsible for moderate-to-severe diarrhea in low- and middle-income countries (LMICs).

Processing of the major autolysin of E. faecalis, AtlA, by the zinc-metalloprotease, GelE, impacts AtlA septal localization and cell separation.

AtlA is the major peptidoglycan hydrolase of Enterococcus faecalis involved in cell division and cellular autolysis. The secreted zinc metalloprotease, gelatinase (GelE), has been identified as an important regulator of cellular function through post-translational modification of protein substrates. AtlA is a known target of GelE, and their interplay has been proposed to regulate AtlA function.

Differential Penicillin-Binding Protein 5 (PBP5) Levels in the Enterococcus faecium Clades with Different Levels of Ampicillin Resistance.

Ampicillin resistance in Enterococcus faecium is a serious concern worldwide, complicating the treatment of E. faecium infections. Penicillin-binding protein 5 (PBP5) is considered the main ampicillin resistance determinant in E.

Enterococcus faecalis Ebp pili are important for cell-cell aggregation and intraspecies gene transfer.

Enterococcus faecalis is an opportunistic pathogen that ranks among the leading causes of biofilm-associated infections. We previously demonstrated that the endocarditis- and biofilm-associated pili (Ebp) of E. faecalis play a major role in biofilm formation, adherence to abiotic surfaces and experimental infections.

Role of the Emp Pilus Subunits of Enterococcus faecium in Biofilm Formation, Adherence to Host Extracellular Matrix Components, and Experimental Infection.

Enterococcus faecium is an important cause of hospital-associated infections, including urinary tract infections (UTIs), bacteremia, and infective endocarditis. Pili have been shown to play a role in the pathogenesis of Gram-positive bacteria, including E. faecium We previously demonstrated that a nonpiliated ΔempABC::cat derivative of E.

Gastrointestinal Tract Colonization Dynamics by Different Enterococcus faecium Clades.

Colonization of the gastrointestinal tract (GIT) generally precedes infection with antibiotic-resistant Enterococcus faecium We used a mouse GIT colonization model to test differences in the colonization levels by strains from different E. faecium lineages: clade B, part of the healthy human microbiota; subclade A1, associated with infections; and subclade A2, primarily associated with animals. After mono-inoculation, there was no significant difference in colonization (measured as the geometric mean number of colony-forming units per gram) by the E.

The Enterococcus faecalis EbpA Pilus Protein: Attenuation of Expression, Biofilm Formation, and Adherence to Fibrinogen Start with the Rare Initiation Codon ATT.

Unlabelled: The endocarditis and biofilm-associated pili (Ebp) are important in Enterococcus faecalis pathogenesis, and the pilus tip, EbpA, has been shown to play a major role in pilus biogenesis, biofilm formation, and experimental infections. Based on in silico analyses, we previously predicted that ATT is the EbpA translational start codon, not the ATG codon, 120 bp downstream of ATT, which is annotated as the translational start. ATT is rarely used to initiate protein synthesis, leading to our hypothesis that this codon participates in translational regulation of Ebp production.

Enterococcus faecium PBP5-S/R, the missing link between PBP5-S and PBP5-R.

During a study to investigate the evolution of ampicillin resistance in Enterococcus faecium, we observed that a number of E. faecium strains, mainly from the recently described subclade A2, showed PBP5 sequences in between PBP5-S and PBP5-R. These hybrid PBP5-S/R patterns reveal a progression of amino acid changes from the S form to the R form of this protein; however, these changes do not strictly correlate with changes in ampicillin MICs.

Contribution of individual Ebp Pilus subunits of Enterococcus faecalis OG1RF to pilus biogenesis, biofilm formation and urinary tract infection.

The endocarditis and biofilm-associated pilus (Ebp) operon is a component of the core genome of Enterococcus faecalis that has been shown to be important for biofilm formation, adherence to host fibrinogen, collagen and platelets, and in experimental endocarditis and urinary tract infection models. Here, we created single and double deletion mutants of the pilus subunits and sortases; next, by combining western blotting, immunoelectron microscopy, and using ebpR in trans to increase pilus production, we identified EbpA as the tip pilin and EbpB as anchor at the pilus base, the latter attached to cell wall by the housekeeping sortase, SrtA. We also confirmed EbpC and Bps as the major pilin and pilin-specific sortase, respectively, both required for pilus polymerization.

Alternative splicing and subfunctionalization generates functional diversity in fungal proteomes.

Alternative splicing is commonly used by the Metazoa to generate more than one protein from a gene. However, such diversification of the proteome by alternative splicing is much rarer in fungi. We describe here an ancient fungal alternative splicing event in which these two proteins are generated from a single alternatively spliced ancestral SKI7/HBS1 gene retained in many species in both the Ascomycota and Basidiomycota.

First identification of OXA-72 carbapenemase from Acinetobacter pittii in Colombia.

OXA-72 has been reported in few countries around the world. We report the first case in Colombia in an Acinetobacter pittii clinical isolate. The arrival of a new OXA, into a country with high endemic resistance, poses a significant threat, especially because the potential for widespread dissemination is considerable.

[Antimicrobial resistance of Gram negative bacilli isolated from tertiary-care hospitals in Colombia].

Introduction: Antimicrobial resistance has been identified as one of the major public health problems worldwide. To facilitate its control, bacterial resistance levels must be monitored permanently by effective surveillance systems.

Objective: To describe the antimicrobial resistance patterns of Gram negative bacilli in Colombian hospitals over a 3-year period.

First characterization of CTX-M-15-producing Escherichia coli ST131 and ST405 clones causing community-onset infections in South America.

CTX-M-15-producing Escherichia coli has emerged worldwide as an important pathogen associated with community-onset infections, but in South America reports are scarce. We document the presence of CTX-M-15-producing E. coli of the international ST131 and ST405 clones in Colombia and present the first molecular characterization of these isolates in South America.

Novel VIM metallo-beta-lactamase variant, VIM-24, from a Klebsiella pneumoniae isolate from Colombia.

We report the emergence of a novel VIM variant (VIM-24) in a Klebsiella pneumoniae isolate in Colombia. The isolate displays MICs for carbapenems below the resistance breakpoints, posing a real challenge for its detection. The blaVIM-24 gene was located within a class 1 integron carried on a large plasmid.

[Genetic characterization of the interleukin 1 b polymorphisms -511, -31 y +3954 in a Colombian population with dyspepsia].

Introduction: The human interleukin-1b gen (IL-1 b) polymorphisms such as -511, -31 and +3954 have been associated with the presence of gastric cancer, due to the inhibitor effect that this protein has on acid secretion in the stomach. This facility can enhance the colonization and infection by agents like Helicobactor. pylori and the genesis of preneoplastic states that can lead to cancer development.

Emergence of KPC-producing Pseudomonas aeruginosa in Trinidad and Tobago.

In 2006, the first isolate of KPC-2-producing Pseudomonas aeruginosa in the world was identified in Colombia. Recently, similar strains have been reported in Puerto Rico. We now report KPC-2-producing P.