Antibody-Mediated Serum Resistance Protects Pseudomonas aeruginosa During Bloodstream Infections.

Background: Pseudomonas aeruginosa is a frequent pathogen isolated from bacterial bloodstream infection (BSI) and is associated with high mortality. To survive in the blood, P aeruginosa must resist the bactericidal action of complement (ie, serum killing). Antibodies usually promote serum killing through the classical complement pathway; however, "cloaking antibodies" (cAbs) have been described, which paradoxically protect bacteria from serum killing.

A multiomic approach to defining the essential genome of the globally important pathogen Corynebacterium diphtheriae.

Diphtheria is a respiratory disease caused by Corynebacterium diphtheriae. While the toxin-based vaccine has helped control outbreaks of the disease since the mid-20th century there has been an increase in cases in recent years, including systemic infections caused by non-toxigenic C. diphtheriae strains.

Redefining the bacterial Type I protein secretion system.

Type I secretion systems (T1SS) are versatile molecular machines for protein transport across the Gram-negative cell envelope. The archetypal Type I system mediates secretion of the Escherichia coli hemolysin, HlyA. This system has remained the pre-eminent model of T1SS research since its discovery.

TcpA from the Clostridium perfringens plasmid pCW3 is more closely related to the DNA translocase FtsK than to coupling proteins.

Conjugative DNA transfer is a major factor in the dissemination of antibiotic resistance and virulence genes. In the Gram-positive pathogen Clostridium perfringens, the majority of conjugative plasmids share the conserved tcp locus that governs the assembly of the transfer system. Here, we describe multiple structures of the coupling protein TcpA, an essential ATPase that is suggested to provide the mechanical force to propel the DNA through the transfer apparatus.

Antibody-Dependent Enhancement of Bacterial Disease: Prevalence, Mechanisms, and Treatment.

Antibody-dependent enhancement (ADE) of viral disease has been demonstrated for infections caused by flaviviruses and influenza viruses; however, antibodies that enhance bacterial disease are relatively unknown. In recent years, a few studies have directly linked antibodies with exacerbation of bacterial disease. This ADE of bacterial disease has been observed in mouse models and human patients with bacterial infections.

Forensic genomics of a novel type from a neonatal intensive care unit in China reveals patterns of colonization, evolution and epidemiology.

During March 2017, a neonatal patient with severe diarrhoea subsequently developed septicaemia and died, with isolated as the causative microorganism. In keeping with infection control protocols, the coincident illness of an attending staff member and three other neonates with infection triggered an outbreak response, leading to microbiological assessment of isolates collected from the staff member and all 21 co-housed neonates. Multilocus sequence typing and genomic sequencing identified that the isolates from the 21 neonates were of a new sequence type, ST2727, and taxonomically belonged to subsp.

Investigation of LuxS-mediated quorum sensing in .

Autoinducer-2 (AI-2) quorum sensing is a bacterial communication system that responds to cell density. The system requires activity to produce AI-2, which can regulate gene expression and processes such as biofilm formation. To investigate the role of in biofilm formation and gene expression in the nosocomial pathogen .

An Outbreak of Carbapenem-Resistant and Hypervirulent in an Intensive Care Unit of a Major Teaching Hospital in Wenzhou, China.

Carbapenem-resistant, hypervirulent (CR-hvKP) has recently emerged as a significant threat to public health. In this study, 29 isolates were isolated from eight patients admitted to the intensive care unit (ICU) of a comprehensive teaching hospital located in China from March 2017 to January 2018. Clinical information of patients was the basis for the further analyses of the isolates including antimicrobial susceptibility tests, identification of antibiotic resistance and virulence gene determinants, multilocus sequence typing (MLST), -macrorestriction by pulsed-field gel electrophoresis (PFGE).

Polymyxin resistance in Klebsiella pneumoniae: multifaceted mechanisms utilized in the presence and absence of the plasmid-encoded phosphoethanolamine transferase gene mcr-1.

Objectives: Until plasmid-mediated mcr-1 was discovered, it was believed that polymyxin resistance in Gram-negative bacteria was mainly mediated by the chromosomally-encoded EptA and ArnT, which modify lipid A with phosphoethanolamine (pEtN) and 4-amino-4-deoxy-l-arabinose (l-Ara4N), respectively. This study aimed to construct a markerless mcr-1 deletion mutant in Klebsiella pneumoniae, validate a reliable reference gene for reverse transcription quantitative PCR (RT-qPCR) and investigate the interactions among mcr-1, arnT and eptA, in response to polymyxin treatments using pharmacokinetics/pharmacodynamics (PK/PD).

Methods: An isogenic markerless mcr-1 deletion mutant (II-503Δmcr-1) was generated from a clinical K.

An investigation into the Omp85 protein BamK in hypervirulent Klebsiella pneumoniae, and its role in outer membrane biogenesis.

Members of the Omp85 protein superfamily have important roles in Gram-negative bacteria, with the archetypal protein BamA being ubiquitous given its essential function in the assembly of outer membrane proteins. In some bacterial lineages, additional members of the family exist and, in most of these cases, the function of the protein is unknown. We detected one of these Omp85 proteins in the pathogen Klebsiella pneumoniae B5055, and refer to the protein as BamK.

Extensively Drug-Resistant Causing Nosocomial Bloodstream Infections in China: Molecular Investigation of Antibiotic Resistance Determinants, Informing Therapy, and Clinical Outcomes.

The rise in diversity of antimicrobial resistance phenotypes seen in is becoming a serious antibiotic management problem. We sought to investigate the molecular characteristics and clinical implications of extensively drug-resistant (XDR) isolated from different nosocomial bloodstream infections (BSIs) patients from July 2013 to November 2015. Even in combination treatment, meropenem did not protect against mortality of BSIs patients ( = 0.