SXT/R391 integrative and conjugative elements in Proteus species reveal abundant genetic diversity and multidrug resistance.

SXT/R391 integrative and conjugative elements (ICEs) are self-transmissible mobile genetic elements that are found in most members of Enterobacteriaceae. Here, we determined fifteen SXT/R391 ICEs carried by Proteus isolates from food (4.2%) and diarrhoea patients (17.3%). BLASTn searches against GenBank showed that the fifteen SXT/R391 ICEs were closely related to that from different Enterobacteriaceae species, including Proteus mirabilis. Using core gene phylogenetic analysis, the fifteen SXT/R391 ICEs were grouped into six distinct clusters, including a dominant cluster and three clusters that have not been previously reported in Proteus isolates. The SXT/R391 ICEs shared a common structure with a set of conserved genes, five hotspots and two variable regions, which contained more foreign genes, including drug-resistance genes. Notably, a class A ß-lactamase gene was identified in nine SXT/R391 ICEs. Collectively, the ICE-carrying isolates carried resistance genes for 20 tested drugs. Six isolates were resistant to chloramphenicol, kanamycin, streptomycin, trimethoprim-sulfamethoxazole, sulfisoxazole and tetracycline, which are drug resistances commonly encoded by ICEs. Our results demonstrate abundant genetic diversity and multidrug resistance of the SXT/R391 ICEs carried by Proteus isolates, which may have significance for public health. It is therefore necessary to continuously monitor the antimicrobial resistance and related mobile elements among Proteus isolates.

Tamm-horsfall protein protects against urinary tract infection by proteus mirabilis.

PURPOSE: Proteus mirabilis is a common cause of urinary tract infection. We determined the role of Tamm-Horsfall protein as a host defense factor against the cystitis and pyelonephritis caused by P. mirabilis. MATERIALS AND METHODS: We generated Tamm-Horsfall protein gene knockout mice using homologous recombination. We introduced P. mirabilis transurethrally into the bladder of Tamm-Horsfall protein deficient (THP(-/-)) and genetically similar WT (THP(+/+)) mice. We cultured urine to quantitate the degree of bacteriuria. We examined bladders and kidneys grossly and histomorphometrically to determine the intensity of inflammation. RESULTS: THP(-/-) mice had more severe bacteriuria and cystitis than THP(+/+) mice. THP(-/-) mice had more pyelonephritic abscesses than THP(+/+) mice. The severity of histological pyelonephritis on semiquantitative histomorphometric analysis appeared to be greater in THP(-/-) mice. The difference between the 2 groups approached but did not attain statistical significance (p = 0.053). CONCLUSION: Tamm-Horsfall protein acts as a host defense factor against P. mirabilis induced urinary tract infection.

[Proteus bacilli: features and virulence factors]. / Bakterie z rodzaju Proteus--cechy i czynniki chorobotwórczosci.

In this article, different aspects of virulence factors of Proteus bacilii (P. mirabilis, P. vulgaris, P. penneri i P. hauseri) are presented. These are opportunistic pathogens that cause different kinds of infections, most frequently of the urinary tract. These bacteria have developed several virulence factors, such as adherence due to the presence of fimbriae or afimbrial adhesins, invasiveness, swarming phenomenon, hemolytic activity, urea hydrolysis, proteolysis, and endotoxicity. Below we focus on data concerning the molecular basis of the pathogenicity of Proteus bacilli.

Proteus mirabilis fimbriae (PMF) are important for both bladder and kidney colonization in mice.

Proteus mirabilis expresses different types of fimbriae simultaneously. Several fimbrial types have been described and their role in the colonization of the urinary tract is under study. Previously, P. mirabilis fimbriae (PMF) have been shown to be associated with bacterial colonization of the lower urinary tract but not of the kidneys. In this study, a pmfA mutant was generated and used in several in vivo and in vitro studies. Two different urinary tract infection models in the mouse and two in vitro assays of bacterial adhesion to uroepithelial cells were performed. Expression of PmfA in a collection of P. mirabilis strains of different sources was also assessed. The results shown here indicate that PMF are involved in both bladder and kidney colonization by P. mirabilis and that these fimbriae are widely distributed among P. mirabilis isolates from different origins since all strains tested expressed PmfA.

Proteus mirabilis and rheumatoid arthritis: no association with the disease.

Proteus mirabilis (PM) is implicated in different studies in the pathogenesis of rheumatoid arthritis (RA) because of the structural homogeneity of its haemolysin B precursor with EQRRAA sequences in DRB 1 haplotype. The aim of the study was to compare the levels of antibodies specific to PM in the sera of patients with RA and healthy controls in our population. Serum samples from 78 consecutive RA patients and 75 healthy controls were analysed for the presence of IgG isotype and total immunoglobulins (IgG + IgA + IgM) against PM using enzyme-linked immunosorbent assay (ELISA) with two kinds of antigen preparations, whole bacteria and SDS-lysed bacterial extract. There was no significant increase in the concentrations of anti- Proteus antibodies (APA) in patients with RA compared to healthy controls in our population, when SDS-lysed bacterial extract or whole bacteria were used as antigen. The APA levels did not correlate with serum CRP levels. We conclude that P. mirabilis has no pathological or aggravating role in RA.

Evaluation of a method using Proteus mirabilis and Pseudomonas aeruginosa to experimentally induce dual infection of the urinary bladder in dogs.

OBJECTIVE: To evaluate a method using Proteus mirabilis and Pseudomonas aeruginosa to experimentally induce dual infection of the urinary bladder in dogs. ANIMALS: 6 healthy mixed-breed dogs. PROCEDURE: Dogs were anesthetized, and cystitis was induced by infusing a solution of salicylic acid in ethanol into the bladder, followed by an inoculum containing field isolates of P. mirabilis and P. aeruginosa. Dogs were examined daily for 21 days after induction of cystitis. On day 21, dogs were euthanatized, and urinary bladder, renal pelvis, and prostate specimens were submitted for bacterial culture. RESULTS: After induction of cystitis, all dogs had evidence of thickening of the bladder wall, dysuria, tenesmus, and hematuria. Urinalysis revealed proteinuria, hematuria, and pyuria. All urine samples obtained on day 21 yielded growth of P. mirabilis, but P. aeruginosa was not cultured from any of these samples. Proteus mirabilis was isolated from bladder, renal pelvis, or prostate specimens from 4 dogs; P. aeruginosa was not isolated from any of the tissue specimens. CONCLUSION: Results suggest that the method used in the present study fails to induce dual infection of the urinary bladder with P. mirabilis and P. aeruginosa. The inability to establish a persistent dual infection with this method may have been a result of insufficient pathogenicity of the Pseudomonas isolate or an inadequacy of the experimental design.

Potential virulence factors of Proteus bacilli.

The object of this review is the genus Proteus, which contains bacteria considered now to belong to the opportunistic pathogens. Widely distributed in nature (in soil, water, and sewage), Proteus species play a significant ecological role. When present in the niches of higher macroorganisms, these species are able to evoke pathological events in different regions of the human body. The invaders (Proteus mirabilis, P. vulgaris, and P. penneri) have numerous factors including fimbriae, flagella, outer membrane proteins, lipopolysaccharide, capsule antigen, urease, immunoglobulin A proteases, hemolysins, amino acid deaminases, and, finally, the most characteristic attribute of Proteus, swarming growth, enabling them to colonize and survive in higher organisms. All these features and factors are described and commented on in detail. The questions important for future investigation of these facultatively pathogenic microorganisms are also discussed.

[The blood circulation of the rectal mucosa and the functional status of the rectal sphincter in acute infectious enterocolitis]. / Krovobih slyzovoï obolonky priamoï kyshky i funktsional'nyi stan rektal'noho sfinktera pry hostrykh infektsiinykh enterokolitakh.

Significant decrease in the tone of the rectal mucosa venules was to be seen at the climax of acute Proteus and Klebsiella enterocolitis, as evidenced by examinations with the aid of rheorectograph and an analyzer of intracavitary motor activity, general blood supply to the intestinal segment under study being not compromised. The tone of the rectal mucous membrane arterioles is raised at the climax of acute dysentery caused by a Flexner type of organism in erosive and haemorrhagic proctosigmoiditis. With the clinical recovery being set in, the blood supply to this area fails to return to normal. The excitability of the inner anal sphincter was noted to be on the increase at the climax of acute S. flexneri dysentery, this showing up predominantly in erosive and haemorrhagic proctosigmoiditis, ceasing to reveal itself in the period of reconvalescentia.

[Regulation of the blood-brain barrier permeability in suppurative-inflammatory diseases of the maxillofacial area]. / Reguliatsiia pronitsaemosti gematoéntsefalicheskogo bar'era pri gnoino-vospalitel'nykh zabolevaniiakh cheliustno-litsevoi oblasti.

Hematoencephalic barrier (HEB) permeability was studied in 78 rabbits. HEB permeability for 32P was examined in animals with phlegmons on the posterior paws and on the maxillofacial area; HEB permeability was sharply increased in the latter group animals. Central cholinolytics and antioxidants were used to normalize this parameter in the rabbits with maxillofacial phlegmons.

[Are cardiac glycosides advisable in the treatment of food poisoning]. / Tselesoobrazny li serdechnye glikozidy v lechenii pishchevykh toksikoinfektsii.

Rheopolycardiological investigation of 76 patients with food toxinfections (FTI) showed that phasic changes of systolic indices in these diseases developed as a result of extracardiac hemodynamic disorders and were of adaptive nature. Strophanthin administration to 20 similar patients at the height of disease brought about no statistically significant changes in systolic indices. It was concluded that the use of cardiac glycosides was inappropriate for the treatment of FTI.

Spontaneous bacterial clearance in experimental urinary tract infections in mice: cellular aspects of the process.

The morphological aspects of Proteus mirabilis clearance from the urinary tract of experimentally infected mice were investigated. For this purpose, two groups of mice were compared: a group infected with the bacterium and a group that had just recovered from the infection. Differences between the two groups were found in extent of bladder and kidney inflammation, depth of infiltration into the bladder wall, and in the increment of bladder volume. There was no clear-cut difference between the two groups in number of lymphocytes and monocytes, but the number of granulocytes was significantly lower in the bladder and kidneys of the recently healed animals. Likewise, the plasma cells were fewer in healed animals than in infected ones, the difference being statistically significant for bladders and on the verge of significance for kidneys.

Structure and function of the rabbit bladder altered by chronic obstruction or cystitis.

Decreased muscle contractility has been observed in association with intercellular collagen deposition after acute urinary obstruction. Chronically induced (2 months) bladder neck obstruction in rabbits produced similar marked changes in the ultrastructure of the bladder wall, with widening of the intercellular spaces and formation of collagen. Resting intravesical pressure was greater in animals with bladder neck obstruction than in the controls, yet response to stimulation was not impaired. Bacterial cystitis, in contrast, produced no consistent change in ultrastructure but the response of intravesical pressure to pelvic nerve stimulation was reduced. It is concluded that intercellular collagen deposition is not responsible per se for impaired conduction of nerve stimuli; perhaps discrete conduction pathways exist in the detrusor and the intercellular electrotonic spread of action potentials is not essential for contraction.

Marked suppression of thyroid function in rats with gram-negative septicemia.

Gram-negative septicemia was induced in rats by two daily injections of fecal mixture into the thigh, after which the thyroid function was markedly suppressed for 2 days. Iodine metabolism was studied by organ radioassay and by imaging with a multiwire proportional chamber (MWPC) at various time intervals after intravenous injection of 125I. Plasma T3, T4, and TSH, measured by radioimmunoassays, were suppressed, as were the T3-resin uptakes. Fractional blood supply to the thyroid glands of the infected rats, studied by the 81Rb uptake method, was also found to be markedly reduced. Sections of the thyroid glands showed little structural change during the period of marked thyroid suppression. There was no biochemical evidence of renal failure in the septicemic rats.