Günter Naumann

Clonal analysis of Escherichia coli serotype O6 strains from urinary tract infections

A total of 36 Escherichia coli urinary tract isolates (UTI) of serotype O6, with different combinations of capsule (K) and flagellin (H) antigens, were analysed according to the outer membrane pattern (OMP), serum resistance properties, mannose-resistant hemagglutination using various types of erythrocytes, and also for the genetic presence and the expression of P-fimbriae, S fimbriae/F1C fimbriae, Type 1 fimbriae, aerobactin and hemolysin. Twenty selected strains were further analysed by pulsed field gel electrophoresis (PFGE), elaborating genomic profiles by XbaI cleavage and subsequent Southern hybridization to virulence-associated DNA probes. It could be shown that O6 UTI isolates represent a highly heterogeneous group of strains according to the occurrence and combination of these traits. Relatedness on the genetic and the phenotypic level was found for some of the strains exhibiting the same O:K:H:F serotype. DNA long-range mapping further indicated some interesting features, according to the copy number and the genomic linkage of virulence genes.

Structural studies of the O-specific side-chains of the cell-wall lipopolysaccharide from Escherichiacoli O 69

Abstract The structure of the O-specific side-chains of the cell-wall lipopolysaccharide from Escherichia coli O 69 has been investigated. Methylation analysis, n.m.r. spectroscopy, and N -deacetylation-deamination, followed by analysis of the product, were the principal methods used. These studies demonstrate that the O-antigen is composed of tetrasaccharide repeating-units having the following structure: →3)-β- d -GlcNA cp -(1→2)-α- L -Rha p -(1→2)-α- L -Rha p -(1→2)-α- d -Gal p -(1→

Serum Resistance in Different Serotypes of Escherichia coli

Resistance to complement-mediated serum activity is an important virulence factor in E. coli isolated from extraintestinal infections. Because there are no reports about the percentage of serum-resistant E. coli strains in common O serogroups, the study was carried out using Taylors method (75% serum) for the determination of serum resistance of 253 E. coli strains, which had been isolated from urinary tract infections. The strains belonged to 8 common serogroups (O1, O2, O4, O6, O9, O16, O18, and O75) with a frequency of 6 to 24%, 218 (86%) were encapsulated. Among 26 different K antigens, K1 and K5 could be found in 32 and 33%. 25% of all strains investigated were found to be serum-resistant. The percentage of serum-resistant strains was between 11% and 63% in the different O serotypes, the highest frequency was found in O6 (63%) and O2 strains (43%). Among all serum-resistant strains carrying 13 different K antigens, K1 and K5 were the most common ones, with a percentage of 62% altogether. Serum resistance can be expected in strains from urinary tract infections, with a quite varying frequency depending on the O serotype, certain K antigens and other factors.

K-Antigen Identification, Hemolysin Production, and Hemagglutination Types of Escherichia coli 06 Strains Isolated from Patients with Urinary Tract Infections

Serotyping of 1918 Escherichia coli strains isolated in significant cell numbers from the urine of patients with urinary tract infections (UTI) revealed the presence of 117 O6 strains. The K antigens were identified by means of K-specific phages and serological methods. The phages used included a K1 phage pool (phi 1, A-E) and the separate phages phi 2, phi 5, phi 7, phi 12 and phi 13. The presence of H antigens, type 1 fimbriae formation, hemolysin production and mannose-resistant hemagglutination (MRHA) ability with human A, sheep, calf and pig erythrocytes were also analyzed. Six different MRHA types were defined and discussed in relation to the O6:K:H serotype. Remarkably, E. coli O6 strains were found to possess a whole arsenal of virulence factors (K antigens, MRHA, hemolysin). The most common serotypes - O6:K2:H1/H- (26), O6:K5:H1/H- (35) and O6:K13:H1/H- (20) - differed from each other in some cases in both MRHA type and hemolysin production.

Detection of different fimbriae-like structures on the surface of Staphylococcus saprophyticus

In relation to the ability of adhesiveness to HEp-2-cells the sizes of capsules on three strains of Staphylococcus saprophyticus were examined using an electron microscopic India ink technique. There was a good correlation between small amounts of capsular material and good adherence to the tissue culture cells. In contrast to this a very large capsule could be demonstrated on a strain which adhered only in a poor manner. Some indications of fimbriae-like structures could be confirmed by negative staining. Three different appendages: thick, short sticks, long, branched fimbriae and fine, thin filaments on the surface of S. saprophyticus were detected. The possible functions of these surface structures in the adherence process represented in a hypothetical cell model is discussed.

K-Antigen, Adhärenzfaktor, Dulcitol-Abbau und Hämolysin-Bildung bei E. coli-R-Stämmen aus Urin

Abstract E. coli rough strains (as determined by spontaneous agglutination of in boiled saline suspension) isolated in significant amounts (> 105/ml) from patients with urinary tract infections were investigated for some factors possibly related to virulence. The frequencies of capsular antigen, colonization factor antigen (CFA I), dulcitol fermentation, and hemolysin production are summarized in table 1. 270 (66.2%) out of 408 strains were found to be encapsulated as determined by the inagglutinability of the living strains in saline. 180 (44.1%) strains were able to ferment dulcitol, and evidence for hemolysin production could be demonstrated in 146 (35.8%) strains. The CFA I (demonstrated by a mannose resistant hemagglutination of human red blood cells) was detected in 62 (15.2%) of the E. coli rough strains tested. The frequency of single properties in the presence or absence of capsular antigen is shown in table 2 demonstrating no significant differences in both groups. The most frequent single factor was found to be the capsular antigen with 22.1%, followed by the double combination capsular antigen/dulcitol fermentation (16.7%), dulcitol fermentation alone (10%), and capsular antigen/hemolysin production (9.8%). There were only 5 strains possessing all four factors tested. On the other hand we found 35 (8.6%) rough strains with none of the properties. Some aspects of virulence of E. coli rough strains are discussed.

Escherichia coli-O-Serotypisierung bei verschiedenen Patientengruppen mit Harnwegsinfektionen

ZusammenfassungMit Hilfe von 44 Anti-O-Seren wurden 789Escherichia coli-Stämme, die aus dem Urin von Patienten mit Harnwegsinfektion isoliert wurden, typisiert. Von den 119E. coli-Stämmen aus dem Urin von Kindern waren 49,6% O-typisierbar; nur 3,4% lagen als Rauh-Stämme vor. Von den 357E. coli-Stämmen von Graviden waren 47% O-typisierbar; 12,1% lagen hier als Rauh-Stämme vor. Bei Erwachsenen mit Harnwegsinfektion wurde der höchste Anteil O-typisierbarerE. coli-Stämme registriert (55,4% der 314 Stämme); 8% lagen als Rauh-Stämme vor. Der höhere Anteil vonE. coli-R-Stämmen im Erwachsenenalter einschließlich bei Graviden deutet darauf hin, daß ein pyelonephritischer Prozeß, nachdem er sich im Kindesalter durch virulente Glatt-Stämme etabliert hat, später auch durch Rauh-Stämme unterhalten werden kann. Bestimmte O-Serotypen konnten innerhalb der einzelnen Patientengruppen unterschiedlich häufig nachgewiesen werden. EnteropathogeneE. coli-Stämme wurden bei allen drei Patientengruppen selten nachgewiesen.SummaryUsing 44 anti-O sera 789Escherichia coli strains isolated from the urine of patients with urinary tract infections were typed. Of the 119E. coli strains from the urine of children, 49.6% were O-typable; only 3.4% were rough strains. Of 357 strains from pregnant women, 47% were O-typable; 12.1% were rough strains. The largest proportion of O-typableE. coli strains was found among 314 strains isolated from adults with recurrent urinary tract infections (55.4% of the 314 strains); 8% were rough strains. The higher proportion ofE. coli rough strains in adults, including pregnant women, indicate that once a pyelonephritis process has been established by virulent smooth strains in childhood, it can be sustained by rough strains at a later stage. Certain O serotypes were found to occur with a variable frequency in the individual patient groups. EnteropathogenicE. coli strains were seldom found in any of the three groups.Using 44 anti-O sera 789 Escherichia coli strains isolated from the urine of patients with urinary tract infections were typed. Of the 199 E. coli strains from the urine of children. 49.6% were O-typable; only 3.4% were rough strains. Of 357 strains from pregnant women, 47% were O-typable; 12.1% were rough strains. The largest proportion of O-typable E. coli strains was found among 314 strains isolated from adults with recurrent urinary tract infections (55.4% of the 314 strains); 8% were rough strains. The higher proportion of E. coli rough strains in adults, including pregnant women, indicate that once a pyelonephritis process has been established by virulent smooth strains in childhood, it can be sustained by rough strains at a later stage. Certain O serotypes were found to occur with a variable frequency in the individual patient groups. Enteropathogenic E. coli strains were seldom found in any of the three groups.

Antikörperbeladene Bakterien im Urin bei chronischer Pyelonephritis

ZusammenfassungWir untersuchten die Urine von 67 Erwachsensen mit seit mehreren Jahren bestehender chronischer Pyelonephritis und von 11 Erwachsenen mit Zystitis auf das Vorkommen antikörperbeladener Bakterien. Mit der indirekten Immunfluoreszenz-Technik bestimmten wir außerdem noch die Antikörper-Titer im Serum gegen die aus dem Urin isolierten Keime. Bei allen Patienten mit Zystitis war im Urin keine Antikörper-Beladung der Bakterien nachweisbar, im Serum lagen die Antikörper-Titer im Normbereich. Von den 67 Urinen der Patienten mit chronischer Pyelonephritis ließ sich bei 49 Urinen mit der Immunfluoreszenz-Technik eine Antikörper-Beladung der Bakterien nachweisen. Auch Patienten, die keine antikörperbeladenen Bakterien im Urin hatten, besaßen zum Teil erhöhte Antikörper-Titer im Serum, und Patienten mit antikörperbeladenen Bakterien im Urin wiesen teilweise im Normbereich liegende Antikörper-Titer im Serum auf.Legt man als Bewertungskriterien einen Nachweis einer Antikörper-Beladung der Bakterien im Urin und/oder einen positiven Antikörper-Titer im Serum, bestimmt mittels indirekter Immunfluoreszenz-Technik, zugrunde, ließ sich bei 86,5% der Erwachsenen mit chronischer Pyelonephritis die klinische Diagnose bestätigen.SummaryUsing the direct immunofluorescence technique antibody-coated bacteria were demonstrated in urine samples from 49 of 67 patients with the clinical diagnosis of chronic pyelonephritis, but were not observed in urines from 11 patients with cystitis. A correlation rate was found between the presence of antibody-coated bacteria in the urine sediment and elevated serum antibody titers in the pyelonephritis group as determined by the indirect immunofluorescence technique. Patients with elevated serum antibody titers without antibody-coated bacteria in the urine, and vice versa, were also found. Patients with cystitis did not have elevated serum antibody titers against the homologous strain isolated from the urine.The clinical diagnosis of chronic pyelonephritis could be confirmed in 86.5% of patients taking into account the presence of antibody-coated bacteria and/or elevated serum antibody titers.

Chemotherapy in the Treatment of Periodontopathy

We treated 27 patients suffering from periodontitis with 750 mg/d oxytetracycline over a fortnight and compared them with a control group of 25 patients who received only a placebo. The selection of patients followed certain criteria. For controlling of the success of treatment, we developed a simple model of clinical and microscopical parameters. A significant difference between both groups could be demonstrated six months after starting the treatment.

A Phosphatase-Novobiocin-Mannose-Inhibition Test (PNMITest) for Routine Identification of the Coagulase-Negative Staphylococcal Urinary Tract Pathogens, S. aureus, S. epidermidis, and S. saprophyticus

Abstract A modified Kloos/Schlei fer -scheme proved to be useful in identifying coagulase-negative staphylococci isolated from urine. S. epidermidis (44,2%) and S. saprophyticus (21.5%) were the most frequent species. Analysis of patients confirmed both species as urinary pathogens. Using an abbreviated scheme of 6 characteristics, S. saprophyticus was misclassified in 19.5% of cases. A Phosphatase-Novobiocin-Mannose-Inhibition Test (PNMITest) together with a high NaCl concentration (10%) in combination with a coagulase test seems to be an acceptable compromise for routine identification of the three most important staphylococcal urinary tract pathogens, S. aureus , S. epidermidis , and S. saprophyticus . The technical and financial expenditure can be reduced considerably, because an extended identification has to be applied only to strains which cannot be identified by the PNMI-Test.