-
PLoS Pathogens Sep 2022Bacteria from the genus Providencia are ubiquitous Gram-negative opportunistic pathogens, causing "travelers' diarrhea", urinary tract, and other nosocomial infections...
Lipopolysaccharide -mediated resistance to host antimicrobial peptides and hemocyte-derived reactive-oxygen species are the major Providencia alcalifaciens virulence factors in Drosophila melanogaster.
Bacteria from the genus Providencia are ubiquitous Gram-negative opportunistic pathogens, causing "travelers' diarrhea", urinary tract, and other nosocomial infections in humans. Some Providencia strains have also been isolated as natural pathogens of Drosophila melanogaster. Despite clinical relevance and extensive use in Drosophila immunity research, little is known about Providencia virulence mechanisms and the corresponding insect host defenses. To close this knowledge gap, we investigated the virulence factors of a representative Providencia species-P. alcalifaciens which is highly virulent to fruit flies and amenable to genetic manipulations. We generated a P. alcalifaciens transposon mutant library and performed an unbiased forward genetics screen in vivo for attenuated mutants. Our screen uncovered 23 mutants with reduced virulence. The vast majority of them had disrupted genes linked to lipopolysaccharide (LPS) synthesis or modifications. These LPS mutants were sensitive to cationic antimicrobial peptides (AMPs) in vitro and their virulence was restored in Drosophila mutants lacking most AMPs. Thus, LPS-mediated resistance to host AMPs is one of the virulence strategies of P. alcalifaciens. Another subset of P. alcalifaciens attenuated mutants exhibited increased susceptibility to reactive oxygen species (ROS) in vitro and their virulence was rescued by chemical scavenging of ROS in flies prior to infection. Using genetic analysis, we found that the enzyme Duox specifically in hemocytes is the source of bactericidal ROS targeting P. alcalifaciens. Consistently, the virulence of ROS-sensitive P. alcalifaciens mutants was rescued in flies with Duox knockdown in hemocytes. Therefore, these genes function as virulence factors by helping bacteria to counteract the ROS immune response. Our reciprocal analysis of host-pathogen interactions between D. melanogaster and P. alcalifaciens identified that AMPs and hemocyte-derived ROS are the major defense mechanisms against P. alcalifaciens, while the ability of the pathogen to resist these host immune responses is its major virulence mechanism. Thus, our work revealed a host-pathogen conflict mediated by ROS and AMPs.
Topics: Animals; Antimicrobial Peptides; Drosophila melanogaster; Hemocytes; Humans; Lipopolysaccharides; Oxygen; Providencia; Reactive Oxygen Species; Virulence Factors
PubMed: 36084158
DOI: 10.1371/journal.ppat.1010825 -
Microbiology (Reading, England) Apr 2012Enterobacteria of the genus Providencia are opportunistic human pathogens associated with urinary tract and wound infections, as well as enteric diseases. The...
Enterobacteria of the genus Providencia are opportunistic human pathogens associated with urinary tract and wound infections, as well as enteric diseases. The lipopolysaccharide (LPS) O antigen confers major antigenic variability upon the cell surface and is used for serotyping of Gram-negative bacteria. Recently, Providencia O antigen structures have been extensively studied, but no data on the location and organization of the O antigen gene cluster have been reported. In this study, the four Providencia genome sequences available were analysed, and the putative O antigen gene cluster was identified in the polymorphic locus between the cpxA and yibK genes. This finding provided the necessary information for designing primers, and cloning and sequencing the O antigen gene clusters from five more Providencia alcalifaciens strains. The gene functions predicted in silico were in agreement with the known O antigen structures; furthermore, annotation of the genes involved in the three-step synthesis of GDP-colitose (gmd, colD and colC) was supported by cloning and biochemical characterization of the corresponding enzymes. In one strain (P. alcalifaciens O39), no polysaccharide product of the gene cluster in the cpxA-yibK locus was found, and hence genes for synthesis of the existing O antigen are located elsewhere in the genome. In addition to the putative O antigen synthesis genes, homologues of wza, wzb, wzc and (in three strains) wzi, required for the surface expression of capsular polysaccharides, were found upstream of yibK in all species except Providencia rustigianii, suggesting that the LPS of these species may be attributed to the so-called K LPS (K(LPS)). The data obtained open a way for development of a PCR-based typing method for identification of Providencia isolates.
Topics: Cloning, Molecular; DNA, Bacterial; Genetic Loci; Guanosine Diphosphate Sugars; Molecular Sequence Data; Multigene Family; O Antigens; Providencia; Sequence Analysis, DNA
PubMed: 22282517
DOI: 10.1099/mic.0.055210-0 -
BMC Nephrology Oct 2021Xanthogranulomatous pyelonephritis (XGP) is a rare and severe chronic inflammatory disease of the renal parenchyma, which is most commonly associated with... (Review)
Review
BACKGROUND
Xanthogranulomatous pyelonephritis (XGP) is a rare and severe chronic inflammatory disease of the renal parenchyma, which is most commonly associated with super-infections by bacteria such as E. coli, Proteus mirabilis, and occasionally Pseudomonas species.
CASE PRESENTATION
Herein, we present a rare case of a patient with XGP infected with Providencia stuartii. Initially, the patient refused nephrectomy and underwent holmium laser lithotripsy and right ureteral stenting, followed by meropenem treatment of 7 days. Relapse occurred in the third month after discharge from the hospital, due to which she underwent a radical nephrectomy.
DISCUSSION
The diagnosis of XGP is confirmed by histopathology. The standard treatment for XGP is antibiotic therapy and radical nephrectomy, but partial nephrectomy may be appropriate in select cases.
Topics: Adult; Enterobacteriaceae Infections; Female; Humans; Providencia; Pyelonephritis, Xanthogranulomatous
PubMed: 34715795
DOI: 10.1186/s12882-021-02565-x -
Antimicrobial Resistance and Infection... 2018Multidrug-resistant Gram-negative bacteria have emerged as major clinical and therapeutic dilemma in hospitals in Ghana.To describe the prevalence and profile of...
BACKGROUND
Multidrug-resistant Gram-negative bacteria have emerged as major clinical and therapeutic dilemma in hospitals in Ghana.To describe the prevalence and profile of infections attributable to multidrug-resistant Gram-negative bacteria among patients at the Komfo Anokye Teaching Hospital in the Ashanti region of Ghana.
METHODS
Bacterial cultures were randomly selected from the microbiology laboratory from February to August, 2015. Bacterial identification and minimum inhibitory concentrations were conducted using standard microbiological techniques and the Vitek-2 automated system. Patient information was retrieved from the hospital data.
RESULTS
Of the 200 isolates, consisting of , , , , , , , , , , , , , , and , 101 (50.5%) and 99 (49.5%) recovered from male and female patients respectively The largest proportion of patients were from age-group ≥60 years (24.5%) followed by < 10 years (24.0%) and least 10-19 years (9.5%) with a mean patient age of 35.95 ± 27.11 (0.2-91) years. The decreasing order of specimen source was urine 97 (48.5%), wound swabs 47 (23.5%), sputum 22 (11.0%) bronchial lavage, nasal and pleural swabs 1 (0.50%). Urinary tract infection was diagnosed in 34.5% of patients, sepsis in 14.5%, wound infections (surgical and chronic wounds) in 11.0%, pulmonary tuberculosis in 9.0% and appendicitis, bacteremia and cystitis in 0.50%. The isolates showed high resistance to ampicillin (94.4%), trimethoprim/sulfamethoxazole (84.5%), cefuroxime (79.0%) and cefotaxime (71.3%) but low resistance to ertapenem (1.5%), meropenem (3%) and amikacin (11%). The average multi-drug resistance was 89.5%, and ranged from 53.8% in spp. to 100.0% in spp. and .
CONCLUSION
Bacterial infections caused by multi-drug resistant (isolates resistant to at least one agent in three or more antibiotic classes) Gram-negative pathogens among patients at Komfo Anokye Teaching Hospital in Kumasi, Ghana are rife and interventions are necessary for their containment.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Bacteremia; Child; Child, Preschool; Drug Resistance, Multiple, Bacterial; Female; Ghana; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Hospitals, Teaching; Humans; Infant; Male; Microbial Sensitivity Tests; Middle Aged; Providencia; Sepsis; Tuberculosis, Pulmonary; Urinary Tract Infections; Wound Infection; Young Adult
PubMed: 29541448
DOI: 10.1186/s13756-018-0324-2 -
Frontiers in Microbiology 2020The bacterial genus is Gram-negative opportunistic pathogens, which have been isolated from a variety of environments and organisms, ranging from humans to animals. , ,...
The bacterial genus is Gram-negative opportunistic pathogens, which have been isolated from a variety of environments and organisms, ranging from humans to animals. , , and are the most common clinical isolates, however, these three species differ in their pathogenicity, antibiotic resistance and environmental adaptation. Genomes of 91 isolates of the genus were investigated to clarify their genetic diversity, focusing on virulence factors, antibiotic resistance genes, and environmental adaptation genes. Our study revealed an open pan-genome for the genus containing 14,720 gene families. Species of the genus exhibited different functional constraints, with the core genes, accessory genes, and unique genes. A maximum-likelihood phylogeny reconstructed with concatenated single-copy core genes classified all isolates into 11 distant groups. Comprehensive and systematic comparative genomic analyses revealed that specific distributions of virulence genes, which were highly homologous to virulence genes of the genus , contributed to diversity in pathogenicity of , , and . Furthermore, multidrug resistance (MDR) phenotypes of isolates of and were predominantly due to resistance genes from class 1 and 2 integrons. In addition, and harbored more genes related to material transport and energy metabolism, which conferred a stronger ability to adapt to diverse environments. Overall, our study provided valuable insights into the genetic diversity and functional features of the genus , and revealed genetic mechanisms underlying diversity in pathogenicity, antibiotic resistance and environmental adaptation of members of this genus.
PubMed: 33193173
DOI: 10.3389/fmicb.2020.572642 -
Biotechnology Reports (Amsterdam,... Sep 2022Crude oil contamination introduces multiple threats to human health and the environment, most of which are from toxic heavy metals. Heavy metals cause significant...
Crude oil contamination introduces multiple threats to human health and the environment, most of which are from toxic heavy metals. Heavy metals cause significant threats because of their persistence, toxicity, and bio-accumulation. Biomineralization, performed through many microbial processes, can lead to the immobilization of heavy metals in formed minerals. The potential of the microbially carbonate-induced precipitation (MICP) in removal by biomineralization of several heavy metals was investigated. A collection of diverse 11 bacterial strains exhibited ureolytic activity and tolerance to heavy metals when growing in Luria-Bertani (LB) and urea medium. Determination of the minimum inhibitory concentrations (MIC) revealed that heavy metal toxicity was arranged as Cd > Ni > Cr > Cu > Zn. Three hydrocarbon-degrading bacterial strains (two of and one of ) exhibited the highest tolerance (MIC > 5 mM) to Cu, Cr, Zn, and Ni, whereas Cd exerted significantly higher toxicity with MIC <1 mM. At all MICP conditions, different proportions of calcium carbonate (calcite) and calcium phosphate (brushite) were formed. strains (QZ5 and QZ9) exhibited the highest removal efficiency of Cr (100%), whereas strain (QZ2) showed 100% removal of Zn. Heavy metal complexes were found as well. Cd removal was evidenced by the formation of cadmium phosphate induced by bacterial activity. Our study confirmed that hydrocarbon-degrading ureolytic bacteria not only can tolerate heavy metal toxicity but also have the capability to co-precipitate heavy metals. These findings indicate an effective and novel biological approach to bioremediate petroleum hydrocarbons and immobilize multiple heavy metals with mineral formation. This is of high importance for ecological restoration via stabilization of soil and alleviation of heavy metal toxicity.
PubMed: 35755319
DOI: 10.1016/j.btre.2022.e00747 -
Viruses Mar 2022is an emerging opportunistic Gram-negative pathogen with reports of increasing antibiotic resistance. Pan-drug resistant (PDR) infections are a growing concern,...
is an emerging opportunistic Gram-negative pathogen with reports of increasing antibiotic resistance. Pan-drug resistant (PDR) infections are a growing concern, demonstrating a need for the development of alternative treatment options which is fueling a renewed interest in bacteriophage (phage) therapy. Here, we identify and characterize phage vB_PreP_EPr2 (EPr2) with lytic activity against PDR MRSN 845308, a clinical isolate that carries multiple antibiotic resistance genes. EPr2 was isolated from an environmental water sample and belongs to the family , subfamily and genus , with a genome size of 41,261 base pairs. Additional phenotypic characterization showed an optimal MOI of 1 and a burst size of 12.3 ± 3.4 PFU per bacterium. EPr2 was determined to have a narrow host range against a panel of clinical strains. Despite this fact, EPr2 is a promising lytic phage with potential for use as an alternative therapeutic for treatment of PDR infections.
Topics: Anti-Bacterial Agents; Bacteriophages; Host Specificity; Providencia
PubMed: 35458437
DOI: 10.3390/v14040708 -
BMJ (Clinical Research Ed.) Jul 1989
Topics: Diarrhea; Feces; Humans; Proteus Infections; Providencia; Travel
PubMed: 2504344
DOI: 10.1136/bmj.299.6691.94-a -
Frontiers in Microbiology 2022A novel chromosome-encoded aminoglycoside -nucleotidyltransferase AadA33 was identified in strain P13. The AadA33 shares the highest amino acid identity of 51.28% with...
A novel chromosome-encoded aminoglycoside -nucleotidyltransferase AadA33 was identified in strain P13. The AadA33 shares the highest amino acid identity of 51.28% with the function characterized AadA31. Antibiotic susceptibility testing and enzyme kinetics analysis revealed that the function of AadA33 is to mediate spectinomycin and streptomycin resistance. The recombinant strain harboring (pUCP20-/ DH5α) displayed >256- and 128-fold increases in the minimum inhibitory concentration levels to spectinomycin and streptomycin, respectively, compared with the control strains pUCP20/DH5α. Enzyme kinetic parameters manifested the substrate of AadA33 including spectinomycin and streptomycin, with / of 3.28 × 10 (M s) and 3.37 × 10 (M s), respectively. Bioinformatics analysis revealed its structural mechanism of antimicrobial resistance, genetic context, and phylogenetic relationship with other aminoglycoside -nucleotidyltransferases. This study of AadA33 contributed to understanding the function and resistance mechanism of aminoglycoside -nucleotidyltransferase.
PubMed: 36177473
DOI: 10.3389/fmicb.2022.990739 -
Veterinary Medicine International 2021[This corrects the article DOI: 10.1155/2020/8874747.].
[This corrects the article DOI: 10.1155/2020/8874747.].
PubMed: 33564390
DOI: 10.1155/2021/2954176