Socialization of Providencia stuartii enables resistance to environmental insults.

Providencia stuartii is a highly-social pathogen responsible for nosocomial chronic urinary tract infections. The bacterium indeed forms floating communities of cells (FCC) besides and prior-to canonical surface-attached biofilms (SAB). Within P. stuartii FCC, cells are riveted one to another owing to by self-interactions between its porins, viz. Omp-Pst1 and Omp-Pst2. In pathophysiological conditions, P. stuartii is principally exposed to high concentrations of urea, ammonia, bicarbonate, creatinine and to large variations of pH, questioning how these environmental cues affect socialization, and whether formation of SAB and FCC protects cells against those. Results from our investigations indicate that FCC and SAB can both form in the urinary tract, endowing cells with increased resistance and fitness. They additionally show that while Omp-Pst1 is the main gateway allowing penetration of urea, bicarbonate and ammonia into the periplasm, expression of Omp-Pst2 enables resistance to them.

Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

Capsular polysaccharides of pathogenic bacteria have been reported to be effective vaccines against diseases caused by them. Providencia stuartii is a class of enterobacteria of the family Providencia that is responsible for several antibiotic resistant infections, particularly urinary tract infections of patients with prolonged catheterization in hospital settings. Towards the goal of development of vaccine candidates against this pathogen, we herein report the total synthesis of a trisaccharide repeating unit of the O-antigen polysaccharide of the P. stuartii O49 serotype containing the →6)-β-ᴅ-Galp-(1→3)-β-ᴅ-GalpNAc(1→4)-α-ᴅ-Galp(1→ linkage. The synthesis of the trisaccharide repeating unit was carried out first by a linear strategy involving the [1 + (1 + 1 = 2)] assembly, followed by a one-pot synthesis involving [1 + 1 + 1] strategy from the corresponding monosaccharides. The one-pot method provided a higher yield of the protected trisaccharide intermediate (73%) compared to the two step synthesis (66%). The protected trisaccharide was then deprotected and N-acetylated to finally afford the desired trisaccharide repeating unit as its α-p-methoxyphenyl glycoside.

Bronchopneumonia in sheep associated with Providencia stuartii

Bacteria of the genus Providencia are opportunistic pathogens in humans, widely distributed in the environment and associated with greater resistance to antibiotics, and this being uncommon the association with clinical diseases. This study reports the isolation of P. stuartii in two sheep that presented clinical signs of pneumonia. At necropsy there was severe and acute fibrinopurulent bronchopneumonia. Histologically, there were infiltrated neutrophils and fibrin in the alveolar lumen, and the alveolar septa presented multifocal thickening with moderate proliferation of pneumocytes and mononuclear interstitial infiltrate. Providencia sp. was isolated in the microbiological tests of the lung and tracheal secretions. The isolate was subjected to DNA extraction, polymerase chain reaction (PCR) for the 16SrRNA gene and sequencing of genomic DNA, which demonstrated 100% homology with P. stuartii. This is the first report of the presence of this microorganism as a cause of interstitial and fibrinopurulent bronchopneumonia in sheep. Therefore, it is suggested that epidemiological surveillance strategies should be carried out in animals to better understand their role in the dissemination of this pathogen.

Enterobacter hormaechei in the intestines of housefly larvae promotes host growth by inhibiting harmful intestinal bacteria

Background As a pervasive insect that transmits a variety of pathogens to humans and animals, the housefly has abundant and diverse microbial communities in its intestines. These gut microbes play an important role in the biology of insects and form a symbiotic relationship with the host insect. Alterations in the structure of the gut microbial community would affect larval development. Therefore, it is important to understand the mechanism regulating the influence of specific bacteria on the development of housefly larvae. Methods For this study we selected the intestinal symbiotic bacterium Enterobacter hormaechei, which is beneficial to the growth and development of housefly larvae, and used it as a probiotic supplement in larval feed. 16S rRNA gene sequencing technology was used to explore the effect of E. hormaechei on the intestinal flora of housefly larvae, and plate confrontation experiments were performed to study the interaction between E. hormaechei and intestinal microorganisms. Results The composition of the gut microflora of the larvae changed after the larvae were fed E. hormaechei, with the abundance of Pseudochrobactrum, Enterobacter and Vagococcus increasing and that of Klebsiella and Bacillus decreasing. Analysis of the structure and interaction of larval intestinal flora revealed that E. hormaechei inhibited the growth of harmful bacteria, such as Pseudomonas aeruginosa, Providencia stuartii and Providencia vermicola, and promoted the reproduction of beneficial bacteria. Conclusions Our study has explored the influence of specific beneficial bacteria on the intestinal flora of houseflies. The results of this study reveal the important role played by specific beneficial bacteria on the development of housefly larvae and provide insight for the development of sustained biological agents for housefly control through interference of gut microbiota. Graphical abstract

A Patient With Multiple Carbapenemase Producers Including an Unusual Citrobacter sedlakii Hosting an IncC blaNDM-1- and armA-carrying Plasmid

Background. Patients colonized with multiple species of carbapenemase-producing Enterobacterales (CPE) are increasingly observed. This phenomenon can be due to the high local prevalence of these pathogens, the presence of important host risk factors, and the great genetic promiscuity of some carbapenemase genes. Methods. We analyzed 4 CPE (Escherichia coli, Klebsiella pneumoniae, Providencia stuartii, Citrobacter sedlakii), 1 extended-spectrum cephalosporin-resistant K. pneumoniae (ESC-R-Kp), and 1 carbapenemase-producing Acinetobacter baumannii simultaneously isolated from a patient transferred from Macedonia. Susceptibility tests were performed using a microdilution MIC system. The complete genome sequences were obtained by using both short-read and long-read whole-genome sequencing technologies. Results. All CPE presented high-level resistance to all aminoglycosides due to the expression of the armA 16S rRNA methylase. In C. sedlakii and E. coli (ST69), both the carbapenemase blaNDM-1 and armA genes were located on an identical IncC plasmid of type 1a. The K. pneumoniae (ST268) and P. stuartii carried chromosomal blaNDM-1 and blaOXA-48, respectively, while the ESC-R-Kp (ST395) harbored a plasmid-located blaCTX-M-15. In the latter 3 isolates, armA-harboring IncC plasmids similar to plasmids found in C. sedlakii and E. coli were also detected. The A. baumannii strain possessed the blaOXA-40 carbapenemase gene. Conclusions. The characterization of the genetic organization of IncC-type plasmids harbored by 3 different species from the same patient offered insights into the evolution of these broad- host-range plasmids. Moreover, we characterized here the first complete genome sequence of a carbapenemase-producing C. sedlakii strain, providing a reference for future studies on this rarely reported species.

Immobilization of Providencia stuartii Cells in Pumice Stone and Its Application for N-Acetylglucosamine Production

Research background. Shrimp shells contain chitin that can further be processed into N-acetylglucosamine which has been extensively used to treat joint damage. Providencia stuartii isolated form previous research has strong chitinolytic activity and may be utilized in the form of immobilized cells to be used in repeated fermentation. Pumice is a porous and rigid stone that offers superior mechanical strength, making it suitable to be used for immobilization process. Experimental approach. The research used experimental method to conduct the submerged fermentation process with different pumice stone size and pumice stone:growth medium ratio (m/V). The fermentation was carried out for 4 days at 37 C and pH of 7.0. The optimum pumice stone size and pumice stone:growth medium ratio (m/V) were used to determine the optimum fermentation cycle to produce N-acetylglucosamine. Results and conclusions. Pumice stones of 1.0×1.0×1.0 cm and pumice stone:growth medium ratio (m/V) of 1:5 were found to be the optimum conditions which successfully immobilized (89.99±1.65) % cells and produced (331.37±7.34) g/L N-acetylglucosamine. The highest N-acetylglucosamine concentration of (322.97±2.46) g/L was obtained in the first fermentation cycle which then decreased and remained stable throughout the last three cycles of fermentation. Novelty and scientific contribution. P. stuartii was a strong chitinolytic bacteria previously isolated from rotten shrimp shells and was used for the first time in immobilized form to produce N-acetylglucosamine. The findings in this research showed potential use of P. stuartii cells immobilized in pumice stone for continuous production of N-acetylglucosamine using fermentation method.

Xanthogranulomatous pyelonephritis infected with the Providencia stuartii: a case report and literature 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.

Immobilization of Providencia stuartii Cells in Papaya Trunk Wood for N-acetylglucosamine Production from Pennaeus vannamei Shrimp Shells

Highlight Research AbstractChitin is a natural compound found abundantly in shrimp shells. Chitin can be degraded to produce N-acetylglucosamine, which has wide applications in the food and pharmaceutical fields. Fermentation using chitinolytic microorganisms can be used to produce N-acetylglucosamine from shrimp shells’ chitin. One of the strong chitinolytic bacteria that was isolated from previous research was Providencia stuartii. To provide better stability and efficiency in fermentation, P. stuartii cells were immobilized using entrapment method in papaya trunk wood. The aims of this research were to determine the optimum papaya trunk wood size, ratio of papaya trunk wood and growth medium, as well as the optimum fermentation cycle to produce N-acetylglucosamine from P. vannamei shrimp shells using submerged fermentation method. The research used experimental method with treatment of different sizes of papaya trunk wood (1 x 1 x 1 cm3, 1.5 x 1.5 x 1.5 cm3, and 2 x 2 x 2 cm3), different ratio of papaya trunk wood and growth medium (1:10, 1:15 and 1:20), and 4 fermentation cycles. Results showed that papaya trunk wood with size of 1 x 1 x 1 cm3 and ratio (w/v) of 1:10 could immobilize 87.08±2.05% of P. stuartii cells and produce the highest N-acetylglucosamine concentration, which was 238177.78±3153.48 ppm. The highest N-acetylglucosamine production was obtained from first fermentation cycle and decreased over the last three cycles, but still produced high concentration of N-acetylglucosamine. Therefore, it is possible to perform continuous N-acetylglucosamine production from shrimp shells using P. stuartii cells immobilized in papaya trunk wood.

The sensitivity of planktonic cultures and biofilms of gram-negative bacteria to commercial disinfectant and antiseptic preparations

The in vitro antibacterial activity of 11 commercial disinfectant preparations and 8 antiseptics against 10 strains of the bacteria Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloaceae and Providencia stuartii obtained from international collections and isolated from neuroresuscitation patients in Moscow in 2018 was studied. The sensitivity of planktonic cultures to the preparations was determined by the method of serial dilutions in broth and the spot method on solid nutrient media, the sensitivity of biofilms by the applicator method. A general pattern was revealed: the level of sensitivity to tested disinfectants in clinical strains was lower than in reference strains. It was found that the disinfectants «Mikrobak-Forte», «SAT-22», «Neobak-Oksi» at the concentrations recommended by the manufacturers were effective against bacteria of all test strains, both in the plankton state and in the form of biofilms. On the contrary, the disinfectant preparations «Biodez-Optima», «Biodez-Extra DVU», «Novodez-Aktiv», «Triosept-Oksi», «Tristel Fusion for Surfaces», «Effect-Forte Plus», «Lactic-Oxy» did not have sufficient effectiveness in the concentrations recommended by the manufacturers, therefore it is proposed to use these drugs in higher concentrations. It was found that the disinfectant «Biodez-Extra DVU» is able to inhibit the growth of biofilms of bacteria of the species K. pneumoniae. The ability to suppress the growth of bacterial biofilms of K. pneumoniae, A. baumannii, P. aeruginosa was revealed for the «Triestel Fusion for surfaces disinfectant». The bacteria of all used test strains in the planktonic state were sensitive to all tested antiseptic preparations. However, the biofilms of the clinical strains of P. aeruginosa and P. stuartii. possessed resistance to the antiseptics «Octenidol», «Octenisept», «Miramistin», «Hexoral». Our studies indicate the need for sensitivity analysis of antibacterial drugs in representatives of hospital pathogens, including the modeling of bacterial biofilms, which is a very relevant and important scientific direction, necessary to improve the control of nosocomial infections in the Russian Federation.