Copper affects virulence and diverse phenotypes of uropathogenic Proteus mirabilis.

Background: Copper plays a role in urinary tract infection (UTI) and urinary copper content is increased during Proteus mirabilis UTI. We therefore investigated the effect of copper on uropathogenic P. mirabilis and the underlying mechanisms, focusing on the virulence associated aspects.

sp. nov., isolated from the gut of the beetle , and sp. nov., isolated from a stick insect rearing cage.

Two strains of identified from different experiments are proposed to represent new species. Strain WLa1L2M3 was isolated from the digestive tract of an beetle larva. Strain 09-1422 was isolated from a cage housing the stick insect .

The QseEF Two-Component System-GlmY Small RNA Regulatory Pathway Controls Swarming in Uropathogenic .

Bacterial sensing of environmental signals through the two-component system (TCS) plays a key role in modulating virulence. In the search for the host hormone-sensing TCS, we identified a conserved locus following , a small RNA (sRNA) gene in uropathogenic . Genes of constitute an operon, and QseF binding sites were found in the promoter region.

sp. nov., isolated from the gut of a millipede () from a coconut tree.

During an investigation of microbes associated with arthropods living in decaying coconut trees, a isolate, Milli4, was cultured from the digestive tract of the common Asian millipede, . Sequence analysis of 16S rRNA and genes found that Milli4 was closely related but not identical to Esp-1, B13 and CCA1. Whole genome sequencing suggested that this isolate represents a new species, with average nucleotide identity (OrthoANIu) values of around 83.

Deacidification by FhlA-dependent hydrogenase is involved in urease activity and urinary stone formation in uropathogenic Proteus mirabilis.

Proteus mirabilis is an important uropathogen, featured with urinary stone formation. Formate hydrogenlyase (FHL), consisting of formate dehydrogenase H and hydrogenase for converting proton to hydrogen, has been implicated in virulence. In this study, we investigated the role of P.

A CpxR-Regulated Gene Involved in Biofilm Formation of Uropathogenic Proteus mirabilis.

, a frequent uropathogen, forms extensive biofilms on catheters that are infamously difficult to treat. To explore the mechanisms of biofilm formation by , we performed transposon mutagenesis. A mutant with impaired biofilm formation was isolated.

cAMP receptor protein regulates mouse colonization, motility, fimbria-mediated adhesion, and stress tolerance in uropathogenic Proteus mirabilis.

Cyclic AMP receptor protein (Crp) is a major transcriptional regulator in bacteria. This study demonstrated that Crp affects numerous virulence-related phenotypes, including colonization of mice, motility, fimbria-mediated adhesion, and glucose stress tolerance in uropathogenic Proteus mirabilis. Diabetic mice were more susceptible to kidney colonization by wild-type strain than nondiabetic mice, in which the crp mutant exhibited increased kidney colonization.

Stenotrophomonas maltophilia PhoP, a Two-Component Response Regulator, Involved in Antimicrobial Susceptibilities.

Stenotrophomonas maltophilia, a gram-negative bacterium, has increasingly emerged as an important nosocomial pathogen. It is well-known for resistance to a variety of antimicrobial agents including cationic antimicrobial polypeptides (CAPs). Resistance to polymyxin B, a kind of CAPs, is known to be controlled by the two-component system PhoPQ.

Overexpression of an outer membrane protein associated with decreased susceptibility to carbapenems in Proteus mirabilis.

Proteus mirabilis isolates commonly have decreased susceptibility to imipenem. Previously, we found P. mirabilis hfq mutant was more resistant to imipenem and an outer membrane protein (OMP) could be involved.

New aspects of RpoE in uropathogenic Proteus mirabilis.

Proteus mirabilis is a common human pathogen causing recurrent or persistent urinary tract infections (UTIs). The underlying mechanisms for P. mirabilis to establish UTIs are not fully elucidated.

Serratia marcescens arn, a PhoP-regulated locus necessary for polymyxin B resistance.

Polymyxins, which are increasingly being used to treat infections caused by multidrug-resistant bacteria, perform poorly against Serratia marcescens. To investigate the underlying mechanisms, Tn5 mutagenesis was performed and two mutants exhibiting increased polymyxin B (PB) susceptibility were isolated. The mutants were found to have Tn5 inserted into the arnB and arnC genes.

The RNA chaperone Hfq is involved in stress tolerance and virulence in uropathogenic Proteus mirabilis.

Hfq is a bacterial RNA chaperone involved in the riboregulation of diverse genes via small noncoding RNAs. Here, we show that Hfq is critical for the uropathogenic Proteus mirabilis to effectively colonize the bladder and kidneys in a murine urinary tract infection (UTI) model and to establish burned wound infection of the rats. In this regard, we found the hfq mutant induced higher IL-8 and MIF levels of uroepithelial cells and displayed reduced intra-macrophage survival.

10'(Z),13'(E)-heptadecadienylhydroquinone inhibits swarming and virulence factors and increases polymyxin B susceptibility in Proteus mirabilis.

In this study, we demonstrated that 10'(Z), 13'(E)-heptadecadienylhydroquinone (HQ17-2), isolated from the lacquer tree, could decrease swarming motility and hemolysin activity but increase polymyxin B (PB) susceptibilityof Proteus mirabilis which is intrinsically highly-resistant to PB. The increased PB susceptibility induced by HQ17-2 was also observed in clinical isolates and biofilm-grown cells. HQ17-2 could inhibit swarming in the wild-type and rppA mutant but not in the rcsB mutant, indicating that HQ17-2 inhibits swarming through the RcsB-dependent pathway, a two-component signaling pathway negatively regulating swarming and virulence factor expression.

Characterization of UDP-glucose dehydrogenase and UDP-glucose pyrophosphorylase mutants of Proteus mirabilis: defectiveness in polymyxin B resistance, swarming, and virulence.

Proteus mirabilis is known to be highly resistant to the action of polymyxin B (PB). However, the mechanism underlying PB resistance is not clear. In this study, we used Tn5 transposon mutagenesis to identify genes that may affect PB resistance in P.

Proteus mirabilis pmrI, an RppA-regulated gene necessary for polymyxin B resistance, biofilm formation, and urothelial cell invasion.

Proteus mirabilis is naturally resistant to polymyxin B (PB). To investigate the underlying mechanisms, Tn5 mutagenesis was performed, and a mutant exhibiting increased PB susceptibility was isolated. The mutant was found to have Tn5 inserted into the PpmrI (Proteus pmrI) gene, a gene which may encode a UDP-glucuronic acid decarboxylase.

Role of RppA in the regulation of polymyxin b susceptibility, swarming, and virulence factor expression in Proteus mirabilis.

Proteus mirabilis, a human pathogen that frequently causes urinary tract infections, is intrinsically highly resistant to cationic antimicrobial peptides, such as polymyxin B (PB). To explore the mechanisms underlying P. mirabilis resistance to PB, a mutant which displayed increased (> 160-fold) sensitivity to PB was identified by transposon mutagenesis.

Extensively drug-resistant Stenotrophomonas maltophilia in a tertiary care hospital in Taiwan: microbiologic characteristics, clinical features, and outcomes.

A retrospective study was performed in a university-affiliated referral center from year 1999 to year 2004 to understand the trend of resistance in Stenotrophomonas maltophilia isolates associated with nosocomial infections and describe the emergence of an extensively drug-resistant S. maltophilia (XDRSM). A 49% increase in all types of nosocomial infections and an 85% increase in nosocomial bloodstream infections caused by S.

Invasive pulmonary aspergillosis: high incidence of disseminated intravascular coagulation in fatal cases.

Background And Purpose: Disseminated intravascular coagulation (DIC) is a rarely described finding in invasive pulmonary aspergillosis (IPA) with unclear impact on mortality.

Methods: This study included patients with positive cultures of Aspergillus spp. from respiratory specimens, serological evidence of aspergillosis, or lung biopsy findings supporting aspergillosis treated at National Taiwan University Hospital from January 1999 to June 2005.

Inhibition of swarming and virulence factor expression in Proteus mirabilis by resveratrol.

Resveratrol (3,5,4-trihydroxy-trans-stilbene) is a phytoalexin compound with anti-inflammatory and antioxidant activities. The effect of resveratrol on swarming and virulence factor expression of Proteus mirabilis, an important pathogen infecting the urinary tract, was determined on swarming agar plates with and without the compound. Bacteria harvested at different times were assayed for cell length and the production of flagella, haemolysin and urease.

Empyema thoracis due to Rhizopus oryzae in an allogenic bone marrow transplant recipient.

We describe a case of empyema thoracis caused by Rhizopus oryzae diagnosed in an allogenic bone marrow transplant patient with acute lymphocytic leukemia. The isolate of R. oryzae was recovered from three pleural effusion specimens, which were black in color.

Peritonitis caused by Aspergillus sydowii in a patient undergoing continuous ambulatory peritoneal dialysis.

We describe a patient who received continuous ambulatory peritoneal dialysis and developed catheter-related peritonitis caused by Aspergillus sydowii. Identification of A. sydowii was confirmed by the sequence analysis of the ribosomal RNA genes.

Molecular evidence of recurrent histoplasmosis with 9-year latency in a patient with Addison's disease.

We present a case of fatal histoplasmosis in a patient with Addison's disease and long-term use of corticosteroid. The patient acquired Histoplasma capsulatum in China and initially presented with a laryngeal mass. He developed fulminant pneumonia and respiratory failure 9 years later.