Virulence characteristics of Escherichia coli strains causing acute cystitis in young adults in Iran.

BACKGROUND: Escherichia coli strains that cause cystitis posses virulence properties that facilitate their colonisation and persistence in the bladder. In Iran, despite the high number of the urinary tract infections, very few studies has been done to determine the role of these virulence properties in the pathogenesis of E. coli cyctitis. PATIENTS AND METHODS: Eighty-seven strains of E. coli, isolated from young adults with cystitis in Shiraz, Iran, were examined for the expression of type 1 and P-fimbriae, mannose resistant haemagglutination, haemolysin production, aerobactin-mediated iron uptake, O:K serotypes, biochemical phenotypes (BPTs) and their antibiotic susceptibility patterns. RESULTS: Seventy-six percent of the strains expressed multiple virulence properties. There was a significant correlation between the presence of aerobactin and the expression of type 1 fimbriae. All P-fimbriated strains produced aerobactin with 50% of them also coexpressing haemolysin. Of the 29 different O:K serotypes identified, 42% belonged to serotypes not commonly found among European serotypes associated with UTI. Strains of O groups 4 and 6 expressed more virulence factors than the others. A high resistance against ampicillin, trimethoprim and cotrimoxasol was observed among the isolates with 53% of the isolates showing multiresistance to these three antibiotics. Certain BPTs were also found among O:K serotypes with some containing strains of the same virulence profile. CONCLUSION: We conclude that certain colonal groups of E. coli are commonly associated with cystitis in young adults in Iran with strains possessing a combination of aerobactin and type 1 fimbriae being the dominant ones and belonging to serotypes not commonly found in Europe. We also conclude that the multiple antibiotic resistant E. coli strains causing cyctitis are highly prevalent in this part of the country.

Immune modulation with a staphylococcal preparation in fibromyalgia/chronic fatigue syndrome: relation between antibody levels and clinical improvement.

The aims of this study were to evaluate the serological response to treatment with staphylococcal vaccine in fibromyalgia/chronic fatigue syndrome patients and to explore the relationship between serological response and clinical effect. Twenty-eight patients, half of whom served as controls, were recruited from a 6-month randomised trial in which repeated administration of the staphylococcal toxoid vaccine Staphypan Berna (Berna Biotech, Switzerland) was tested against placebo. Antibody status against extracellular toxins/enzymes, cell-wall components, and enterotoxins was evaluated at baseline and at endpoint. The clinical response to treatment was recorded in rating scales. In the group receiving active treatment, significant serological changes were recorded, whereas no significant changes were found in controls. Treatment led to a significantly increased capacity of serum to neutralise alpha-toxin and a significant increase in serum IgG to alpha-toxin and lipase. Furthermore, the increase in these parameters combined paralleled the improvement in clinical outcome. Thus, the greater the serological response, the greater was the clinical effect. In conclusion, this explorative study has shown that repeated administration of the Staphypan Berna vaccine in patients with fibromyalgia/chronic fatigue syndrome causes a serological response to several staphylococcal antigens, particularly to certain extracellular toxins and enzymes. The results further show that this response is related to the clinical outcome of treatment.

Fenotipos bioquímicos y fagotipos de cepas de Salmonella enteritidis aisladas en Antofagasta, 1997-2000 / Biochemical phenotypes and phage types of Salmonella enteriditis strains isolated in Antofagasta during the period 1997-2000

BACKGROUND: PhP-S48 (Phene Plate Techniques AB), a method based on biochemical phenotypes has been developed and used successfully to typify S enteritidis strains in epidemiological studies. AIM: To identify phenotypes of S enteritidis isolated from eggs, chicken meat and infected humans in Antofagasta during the period 1997-2000. MATERIAL AND METHODS: PhP-S48 and phage typing were used to identify phenotypes of 33 S enteritidis strains, sixteen isolated from poultry and 17 from clinical sources. S enteritidis ATCC17036 was used as control strain. RESULTS: Twelve biochemical phenotypes (BTs) including 4 common (C) and 8 single (S) were identified. BTs C1 y C3 containing 16 and 5 strains, respectively, accounted for 63.6 per cent of the isolates. BT C1 was found in poultry and human sources in the period 1997-2000, and BT C3 was isolated from humans, in the period 1999-2000. Using phage typing, 5 phage types (PT) and 3 strains could be not typed (NTs). PT1 and PT21 were the dominant phage types, with 14 and 13 strains respectively. Strains of PT1 were isolated from poultry and human sources in the period 1997-2000. PT21 was found in poultry samples in the period 1997-1998 and in clinical samples, in the period 1997-1998. Combination of biochemical phenotypes and phage typing divided the strains into 5 phenotypes (BT:PT). Two phenotypes were the most frequently isolated, phenotype C1:1 with 8 isolates found in eggs and humans in 1999, and phenotype C1:21 with 5 strains isolated in 1997-1999. CONCLUSIONS: These results indicate the presence of one persistent and one recently emerged phenotype among S enteritidis in Antofagasta, Chile. PhP-S48 also provided information about a relationship among the strains.

Vaccination with FimH adhesin protects cynomolgus monkeys from colonization and infection by uropathogenic Escherichia coli.

Escherichia coli FimH adhesin mediates binding to the bladder mucosa. In mice, a FimH vaccine protects against bacterial challenge. In this study, 4 monkeys were inoculated with 100 microgram of FimCH adhesin-chaperone complex mixed with MF59 adjuvant, and 4 monkeys were given adjuvant only intramuscularly. After 2 doses (day 0 and week 4), a booster at 48 weeks elicited a strong IgG antibody response to FimH in the vaccinated monkeys. All 8 monkeys were challenged with 1 mL of 108 E. coli cystitis isolate NU14. Three of the 4 vaccinated monkeys were protected from bacteruria and pyuria; all control monkeys were infected. These findings suggest that a vaccine based on the FimH adhesin of E. coli type 1 pili may have utility in preventing cystitis in humans.

Occurrence, diversity, and pathogenicity of halophilic Vibrio spp. and non-O1 Vibrio cholerae from estuarine waters along the Italian Adriatic coast.

The occurrence, diversity, and pathogenicity of Vibrio spp. were investigated in two estuaries along the Italian Adriatic coast. Vibrio alginolyticus was the predominant species, followed by Vibrio parahaemolyticus, non-O1 Vibrio cholerae, and Vibrio vulnificus. By using a biochemical fingerprinting method, all isolates were grouped into nine phenotypes with similarity levels of 75 to 97.5%. The production of toxins capable of causing cytoskeleton-dependent changes was detected in a large number of Vibrio strains. These findings indicate a significant presence of potentially pathogenic Vibrio strains along the Adriatic coast.

Induction of protective immunity after escherichia coli bladder infection in primates. Dependence of the globoside-specific P-fimbrial tip adhesin and its cognate receptor.

Clinical observations suggest that immune mechanisms affect etiology and course of recurrent cystitis. A primate infection model was used to show that primary bladder infection with a uropathogenic P-fimbriated strain (binding to globoside present in the bladder wall) protects against rechallenge with homologous as well as heterologous Escherichia coli strains for up to 5-6 mo. In contrast, mutant derivatives producing P-fimbriae either lacking the tip adhesin protein or carrying an adhesin for which no bladder receptor was present, were unable to induce protection, even though they generated bladder infections of similar duration as the wild type. Therefore, the protective effect mediated by the adhesin seemed to depend upon the presence of its cognate receptor. Since the wild strain also mediated protection against mutants that lacked the adhesin, our data suggest that the globoside-binding PapG adhesin acts as an adjuvant during infection to enhance a specific response against other bacterial antigens. In fact, the globoside-binding strain DS17, but not the mutant DS17-1, unable to bind to membrane-bound globoside, elicited a secretory IgA response to LPS in urine. These in vivo findings suggest that bacterial adhesin-ligand interactions may have signaling functions of importance for the immune response.

Starvation increases the number of coliform bacteria in the caecum and induces bacterial adherence to caecal epithelium in rats.

OBJECTIVE: To investigate the impact of starvation for 24 and 48 h on the number of coliform bacteria in the caecal contents, on the mucosal adherence of coliform bacteria, and on bacterial translocation in rats. DESIGN: Open prospective study. SETTING: University departments of surgery and microbiology, Sweden. MATERIAL: 46 adult male Sprague-Dawley rats. INTERVENTIONS: 19 rats served as controls, and were fed until samples were taken. Six animals were starved for 24 h and another 15 for 48 h, with free access to water, and then anaesthetised before blood, mesenteric lymph nodes (MLN), caecum, and caecal contents were sampled. To verify bacterial translocation in this strain of rats, another six rats underwent controlled haemorrhage for 60 min to reduce the blood pressure to 55 mm Hg mean arterial pressure (MAP). These rats had free access to food and water before haemorrhage but were allowed only water until samples were taken 24 h after haemorrhage. MAIN OUTCOME MEASURES: Presence and number of coliform bacteria in samples taken from caecal contents, caecal epithelium, MLN, and blood. RESULTS: Starvation for 24 h increased the number of coliform bacteria (colony forming units (CFU)/g) in the caecal contents 25-fold (p < 0.05). Starvation for 48 h further increased the number by a factor of 100. The number of coliform bacteria that adhered to the caecal epithelium increased 3,000 times in rats that had been starved for 48 h (p < 0.001). There was no significant difference in translocation (as indicated by cultures from MLN) between rats that had been fed and those that had been starved for 48 h. In 4 of the 6 rats that were bled and then starved for 24 h there were signs of bacterial translocation, which was significantly more than the 1/19 in fed rats (p < 0.05). CONCLUSION: Starvation increases the number of bacteria in the caecal contents and increases bacterial adherence to the caecal epithelium. These changes may contribute to the previously reported increase in bacterial translocation in starved compared wit fed rats that were subjected to stress. The same changes in the gut were observed in animals subjected to haemorrhagic stress in addition to starvation, and in which bacterial translocation was evident.

The PapG-adhesin at the tip of P-fimbriae provides Escherichia coli with a competitive edge in experimental bladder infections of cynomolgus monkeys.

Human urinary tract infection is an infectious disease that depends on a series of host-microbial interactions. The bacteria first colonize the colon and then the periurethral/vaginal areas; they ascend to and infect first the bladder and then the kidneys. Expression of Escherichia coli P-fimbriae constitutes the strongest correlation to renal pathogenicity, but is also related to first-time cystitis in children. The role of P-fimbriae in the preceding steps in the infectious process is unknown. To examine this, we constructed, from a P-fimbriated E. coli strain with a class II G-adhesin preferentially binding to globoside, one isogenic mutant lacking the G-adhesin and another isogenic mutant in which we replaced the papG class II allele with a class III adhesin preferentially binding to the Forssman antigen. We report here the comparison of the adhesin knockout mutant (DS17-8) and the class-switch mutant (DS17-1) with the wild-type (DS17) for in vivo colonization of the gut, vagina, and bladder of cynomolgus monkeys. It was recently shown that the class II tip G-adhesin is a prerequisite for acute pyelonephritis to occur in the monkey model in the absence of other kidney-specific adhesins or obstruction of the urinary flow. Here we show that it is not required for bladder infection but gives a competitive advantage in mixed infections. In the vagina and colon, the G-adhesin gives no competitive advantage.

Antibody response in patients with osteomyelitis of the mandible.

Patients with mandibular osteomyelitis had quantification of 10 antibodies against certain bacterial proteins and polysaccharides. Sera from 31 patients with acute or chronic osteomyelitis of the mandible and from 17 healthy controls were analyzed. Some patients showed low levels of investigated antibodies in general and a lack of specific antiteichoic acid antibodies, as well as of different antipneumococcal antibodies particularly. Two patients with therapy-resistant osteomyelitis showed IgG2 and IgG3 subclass deficiency. They had replacement therapy with intravenous 10 or 15 gm immunoglobulin every 3 weeks for 6 months. Both patients showed considerable improvement in their clinical symptoms after treatment with immunoglobulin. This study indicates that impaired humoral immune response may be of importance in subgroups of patients with osteomyelitis of the mandible.

Glutamine supplementation does not prevent bacterial translocation after non-lethal haemorrhage in rats.

OBJECTIVE: To find out whether supplementation of an enteral diet with glutamine would reduce translocation of bacteria to mesenteric lymph nodes or blood after major haemorrhage in rats. DESIGN: Open randomised study. SETTING: University departments of surgery and microbiology, Sweden. MATERIAL: 49 Sprague-Dawley rats. INTERVENTIONS: Rats were fed enterally for 7 days on diets supplemented with either glutamine or an isonitrogenous amount of non-essential amino acids. After feeding, 8 experimental and 8 control rats underwent sham operation; 9 and 7, respectively, underwent moderate haemorrhage (to 65 mm Hg); and 9 and 8, respectively, underwent severe haemorrhage (50 mm Hg) without reinfusion. MAIN OUTCOME MEASURES: Microbiological analyses of samples of blood and mesenteric lymph nodes taken 24 hours after haemorrhage. RESULTS: The median (interquartile) number of colony forming units/mesenteric lymph nodes after moderate haemorrhage in animals who were given glutamine supplementation was 11 (0-34) and in control animals 20 (0-178). After severe haemorrhage the corresponding figures were 199 (10-310) and 22 (0-187). No pathogens were isolated from blood cultures. CONCLUSION: Glutamine supplementation before haemorrhage did not reduce bacterial translocation to mesenteric lymph nodes in this rat model.

A prospective study of first attacks of inflammatory bowel disease and non-relapsing colitis. Microbiologic findings.

In 105 patients with a first attack of colitis, thorough microbiologic investigations of rectal biopsy, faecal, and serum samples were performed with the aims of identifying the colitis-causing agents and shedding light on factors that may precipitate or aggravate the onset of inflammatory bowel disease. Sixty-one patients were found to have inflammatory bowel disease. In 13 (21%) of these patients microbial findings were positive. Eight of the 61 patients fell ill during or immediately after antibiotic treatment, and 10 while travelling abroad. Forty-one of the 105 patients had non-relapsing colitis. In 32 (78%) of these the microbial findings were positive. Six of these 41 patients fell ill during or immediately after antibiotic treatment, and 14 while travelling abroad. Alteration of the intestinal microflora on travelling, gastrointestinal infection, or treatment with antibiotics seems to precipitate or aggravate the symptoms in latent inflammatory bowel disease. In such patients the mode of onset is often changed from insidious to more acute, which may cause difficulty in differentiation from non-relapsing colitis.

Clinical and histologic features differentiating non-relapsing colitis from first attacks of inflammatory bowel disease.

This is a study of first attacks of colitis, evaluating prospectively the overall course with repeated histologic, clinical, laboratory, and initial microbiologic examinations. Forty-two attacks of colitis could after a follow-up period of 5.5 years be separated into relapsing and non-relapsing types. Relapse was chosen as a prerequisite for a final diagnosis of inflammatory bowel disease. In the non-relapsing group 72% of the patients harboured enteropathogenic bacteria. An insidious onset of diarrhoeal symptoms was highly discriminant of inflammatory bowel disease, whereas an acute onset mostly occurred in patients with non-relapsing colitis. Macroscopic differentiation at sigmoidoscopy was not possible. Distorted crypt architecture (92%) and/or basal plasmacytosis (77%) at initial biopsies strongly indicated inflammatory bowel disease but was also found transiently in patients with infectious colitis (19%). Thus, careful microbiologic and clinical investigation and repeated histologic examinations are necessary to distinguish infectious colitis from inflammatory bowel disease.

Antistaphylococcal antibodies in cystic fibrosis.

Chronic colonization with Staphylococcus aureus is found in 40-50% of the sputum producing patients with cystic fibrosis treated at Stockholm's Cystic Fibrosis Center, Huddinge University Hospital. 30-40% of these patients had increased ELISA IgG antibody titres against teichoic acid and against alpha-toxin. About half of the number of patients showed increased antibody titres to either antigen during infection. Increased antibody titres against staphylococcal antigens were only found in less than or equal to 10% of patients not chronically colonized with S. aureus (no different from the normal population). The serum titres of antistaphylococcal antibodies were significantly higher in the chronically colonized patients (p less than 0.001). Patients who were also chronically harbouring Pseudomonas aeruginosa had the highest titres of both antibodies. The titres increased with clinical signs of infection and were normalized by antimicrobial chemotherapy. To conclude, the use of ELISA IgG antibodies may prove suitable for routine evaluation of the need for, and control of the efficacy of antistaphylococcal chemotherapy in cystic fibrosis.

Experimental mandibular Staphylococcus aureus osteomyelitis; antibody response and treatment with dicloxacillin.

Staphylococcus aureus mandibular osteomyelitis was produced in 20 rabbits by injection of a sclerosing agent and 1 X 10(9) colony-forming units of Staphylococcus aureus V8 into the medullary cavity of the mandible. After 2 weeks all rabbits developed infections. 10 of the rabbits were then treated with dicloxacillin (22.5 mg/kg body weight) every 12 h for 7 days and 10 were left untreated. The animals were sacrificed after 8 weeks and histopathological examination was performed. An enzyme-linked immunosorbent assay (ELISA) was used to measure IgG response against staphylococcal teichoic acid and alpha-toxin during the observation period. In the treated group, there was a decrease in clinical symptoms after the treatment period, while in the untreated group, progression of the infection was a common finding. At the end of the treatment period, Staphylococcus aureus V8 could not be recovered from aspirates obtained from animals in the treatment group, while in the non-treatment group, Staphylococcus aureus V8 could be recovered from abscesses in 6 rabbits. Both in the treated group and in the untreated group, the rabbits showed increasing IgG titers against teichoic acid and alpha-toxin during the first 2-3 weeks. No significant differences in antibody response patterns were noted between the treated and untreated groups and no clear correlation between the immunological response and the severity of the disease was observed.

Antibodies to staphylococcal teichoic acid and alpha toxin in patients with cystic fibrosis.

Enzyme-linked immunosorbent assay (ELISA) was used for IgG antibody determination to teichoic acid and alpha-toxin from Staphylococcus aureus in 65 patients with cystic fibrosis (CF). In patients chronically colonized with S. aureus, elevated titres to teichoic acid were found in 13/35 (37%) patients, to alpha-toxin in 12/35 (34%) and to either antigen in 18/35 (51%). Patients with elevated titres to teichoic acid had a significantly lower X-ray score than patients with normal titres. The highest titres against both teichoic acid and alpha-toxin were seen in patients not receiving optimal treatment. These findings suggest that staphylococci contribute to the tissue damage in CF and that the determination of antibodies especially to staphylococcal teichoic acid might be of value in the diagnosis and management of staphylococcal infections in patients with CF.

Ontogeny of IgG2 antibodies against S. aureus teichoic acid in normal and immunodeficient children.

Anti-teichoic acid antibodies of various subclasses were found to be effectively transported across the placenta during pregnancy. In adults these antibodies are mainly of the IgG2 subclass although substantial amounts of specific IgG1 antibodies may also be found. During ontogeny, specific IgG1 antibodies develop during the second year of life whereas specific IgG2 antibodies appear markedly later. In IgG2 deficient children, prolonged deficiency of specific anti-teichoic acid antibodies was observed, suggesting a lack of maturation of the appropriate idiotype(s). In children who received a bone marrow transplant from adult donors, engraftment of IgG2 producing cells could be seen, thus transferring the ability to produce specific antibodies.

Hydrophobicity of cultured mammalian cells and some effects of bacterial phospholipases C.

Eucaryotic cell surface hydrophobicity was measured as a partition of palmitic acid between the cell surface and the surrounding buffer. The method was found to be independent of cell mass or amount of palmitic acid within a large interval. An estimation of cell stability could also be obtained. The effects of Ca and Mg ions on cell hydrophobicity and stability of mouse myeloma (SP2/O) cells and of Chinese hamster ovary (CHO) cells were determined. This system permits measurement of changes in cell hydrophobicity caused by various additives, e.g. ions, purified bacterial products, antibiotics or cytostatics. Studies were made on these eucaryotic cells treated with purified bacterial phospholipases C from S. aureus and C. perfringens. These enzymes were found to increase the eucaryotic cell membrane hydrophobicity. This finding might indicate that bacterial phospholipases C facilitate bacterial colonization at the start of an infection.

Serological diagnosis of deep Staphylococcus aureus infections by enzyme-linked immunosorbent assay (ELISA) for staphylococcal hemolysins and teichoic acid.

An enzyme-linked immunosorbent assay (ELISA) was used with a purified alpha-toxin preparation to measure the serum IgG, IgM and IgA response in staphylococcal septicaemia and endocarditis. ELISA for IgG antibodies against alpha-toxin was found to be more sensitive than the neutralization test (ASTA). IgM and IgA antibody determination was found to be of limited diagnostic value. A correlation between IgG antibodies to alpha-toxin and purified beta-toxin was found in ELISA, although antibody determination to beta-toxin was a less sensitive diagnostic method. The highest diagnostic sensitivity in deep staphylococcal infections was obtained by parallel performance of ELISA to alpha-toxin and purified teichoic acid. By this approach, 32/35 (91%) patients with endocarditis, 12/14 (86%) with complicated septicaemia and 15/22 (68%) with uncomplicated septicaemia showed increased titres in samples drawn between days 7-30 of disease. Diagnostic sensitivity was further increased to 31/32 (97%) positive patients, when paired or multiple samples from patients with septicaemic staphylococcal disease were analysed.

Occurrence of Clostridium difficile toxin in inflammatory bowel disease.

The occurrence of Clostridium difficile toxin in faeces has been studied in 53 inpatients with inflammatory bowel disease (IBD) at 57 admissions. Before faecal sampling of the patients had had sulphasalazine therapy--17 for more than 1 year--and 16 patients had taken antibiotics on 20 occasions within the last year. The toxin was found in 3 out of 57 samples (5%). In all cases it could be detected only in undiluted stool filtrate. None of the patients was treated for the C. difficile infection; remission was achieved in two of the patients, whereas the third patient with severe ulcerative colitis was referred to colectomy. Our results suggest that neither IBD as such nor long-term sulphasalazine therapy predisposes to occurrence of C. difficile toxin. Antibiotic therapy in these patients does not imply a higher risk of toxin occurrence than in other patients. In our region there is no need for routine screening for this in symptomatic patients with IBD.