The homogeneity of the faecal coliform flora of normal school-girls, characterized by serological and biochemical properties

Lidin-Janson, G; Kaijser, B; Lincoln, K.; Olling, S; Wedel, Hans

doi:10.1007/bf02125493

Cited by 68 publications

(54 citation statements)

References 18 publications

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“…A rectal swab was collected from each consenting subject and processed as described elsewhere (3) to recover an isolated colony of presumptive E. coli, i.e., lactose-and indole-positive, citrate-negative, gram-negative bacilli with characteristic colonial morphology. Previous data show that an arbitrarily selected fecal E. coli colony has an 86% probability of representing the quantitatively predominant clone in the sample (14). Blood and fecal isolates were stored at Ϫ80 C in 15% glycerol pending molecular analysis.…”

Section: Methodsmentioning

confidence: 99%

Molecular Epidemiology and Phylogenetic Distribution of the Escherichia coli pks Genomic Island

Johnson¹,

Johnston²,

et al. 2008

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Epidemiological and phylogenetic associations of the pks genomic island of extraintestinal pathogenic Escherichia coli (ExPEC), which encodes the genotoxin colibactin, are incompletely defined. clbB and clbN (as markers for the 5 and 3 regions of the pks island, respectively), clbA and clbQ (as supplemental pks island markers), and 12 other putative ExPEC virulence genes were newly sought by PCR among 131 published E. coli isolates from hospitalized veterans (62 blood isolates and 69 fecal isolates). Blood and fecal isolates and clbB-positive and -negative isolates were compared for 66 newly and previously assessed traits. Among the 14 newly sought traits, clbB and clbN (colibactin polyketide synthesis system), hra (heat-resistant agglutinin), and vat (vacuolating toxin) were significantly associated with bacteremia. clbB and clbN identified a subset within phylogenetic group B2 with extremely high virulence scores and a high proportion of blood isolates. However, by multivariable analysis, other traits were more predictive of blood source than clbB and clbN were; indeed, among the newly sought traits, only pic significantly predicted bacteremia (negative association). By correspondence analysis, clbB and clbN were closely associated with group B2 and multiple B2-associated traits; by principal coordinate analysis, clbB and clbN partitioned the data set better than did blood versus fecal source. Thus, the pks island was significantly associated with bacteremia, multiple ExPEC-associated virulence genes, and group B2, and within group B2, it identified an especially high-virulence subset. This extends previous work regarding the pks island and supports investigation of the colibactin system as a potential therapeutic target.

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Section: Methodsmentioning

confidence: 99%

Molecular Epidemiology and Phylogenetic Distribution of the Escherichia coli pks Genomic Island

Johnson¹,

Johnston²,

et al. 2008

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“…This indicates that any arbitrarily selected canine fecal E. coli colony should have an ϳ89% probability of representing the predominant fecal E. coli strain, with any other strains present in the sample presumably representing minor strains. Similar calculations have been made for humans (27). Thus, the selected fecal isolates from the present canine subjects were regarded as putatively representing the host's predominant fecal strain at the time of the UTI episode, whereas different genotypes recovered from the same host were regarded as not representing the predominant fecal strain.…”

Section: Methodsmentioning

confidence: 99%

Identification of Urovirulence Traits inEscherichia coliby Comparison of Urinary and RectalE. coliIsolates from Dogs with Urinary Tract Infection

Johnson¹,

Kaster²,

Kuskowski

et al. 2003

J Clin Microbiol

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Spontaneously occurring urinary tract infection (UTI) in dogs was exploited as an experiment of nature to gain insights into UTI pathogenesis in humans. Concurrent urinary and rectal Escherichia coli isolates from 37 dogs with UTI were compared with respect to phylogenetic background, O antigens, and extended virulence genotype. In 54% of the UTI episodes, the dog's urinary and rectal isolates represented the same strain. Urinary isolates differed dramatically from rectal-only isolates in that they derived predominantly from E. coli phylogenetic group B2, expressed typical (human) UTI-associated O antigens, and possessed many virulenceassociated genes, most notably pap elements (P fimbriae), papG (adhesin) allele III, sfa/foc and sfaS (S fimbriae), hly (hemolysin), fyuA (yersiniabactin), iroN (siderophore), and ompT (outer membrane protease T). The 20 urinary isolates that corresponded with the host's predominant rectal strain were no less virulent according to the markers analyzed than were the 17 urinary isolates that differed from the host's predominant rectal strain. These findings suggest that UTI pathogenesis is similar in dogs and humans, provide added support for the special-pathogenicity over the prevalence hypothesis of UTI pathogenesis, and identify numerous specific virulence-associated factors as significant correlates of urovirulence. Dogs spontaneously develop urinary tract infection (UTI)due to strains of Escherichia coli similar to those that cause UTI in humans (4, 6, 7, 15, 18, 25, 30, 42, 45-47, 50, 51). In both host groups, the urinary pathogens typically derive from specific clonal groups within virulence-associated E. coli phylogenetic group B2, express one of several UTI-associated O antigens, and possess specialized virulence-associated factors (VFs) that directly contribute to, or are markers for, an enhanced ability to overcome host defenses and cause extraintestinal disease (15,18,25,41). In both dogs (18, 30) and humans (8,40,49) at the time of a UTI episode, the infecting urinary strain is often the host's predominant rectal E. coli strain, consistent with the fecal reservoir as the proximate source from which pathogens enter the urinary tract. Even healthy dogs are frequently intestinally colonized with uropathogenic E. coli and shed these organisms in their feces (23,50,51).These observations are potentially relevant to human health because they suggest that dogs may pose an infectious threat to humans by providing a reservoir of "human" uropathogenic E. coli for acquisition by susceptible human hosts (15,18,23,25,30,45). In addition, they suggest that the pathogenesis of UTI is similar in dogs and humans, so that dogs might serve as a pathogenetically relevant model system for observational or experimental studies of UTI pathogenesis (15,25).Accordingly, in the present study we took advantage of spontaneously occurring UTI in dogs to address several questions regarding the pathogenesis of UTI in humans. In 37 dogs with UTI, which served as their own controls, we compared concurre...

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“…A single colony was saved for further analysis. Rectal swabs were cultured on modified Drigalski agar plates (22). From each plate, the last three colonies at the end of the streak area, plus any other morphologically distinct colonies, were saved for further analysis.…”

Section: Subjects and Isolatesmentioning

confidence: 99%

“…From each plate, the last three colonies at the end of the streak area, plus any other morphologically distinct colonies, were saved for further analysis. This method provides Ն97% probability of capturing the quantitatively predominant clone in the sample (22). The 65 subjects described here represent all of the previously described 70 men with E. coli FUTI (17) from whom rectal E. coli isolates were available for analysis.…”

Section: Subjects and Isolatesmentioning

confidence: 99%

Phylogenetic and Pathotypic Comparison of Concurrent Urine and RectalEscherichia coliIsolates from Men with Febrile Urinary Tract Infection

Johnson¹,

Scheutz

Ulleryd

et al. 2005

J Clin Microbiol

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Among men with febrile urinary tract infection (FUTI), whether the host's fecal flora is the source for the urine strain ("fecal-urethral" hypothesis), and whether pathogenesis is driven by prevalence versus special pathogenicity, are unknown. Accordingly, pretherapy urine isolates from 65 men with FUTI were compared with concurrent rectal isolates from the same hosts according to serotype, genomic profile, phylogenetic group, and virulence genotype. The host's multiple rectal colonies included only the urine clone in 25% of subjects, the urine clone plus additional clones in 22%, and only nonurine clones in 54%. Compared with the 67 unique rectal clones, the 65 urine isolates were significantly enriched for phylogenetic group B2, virulence-associated serotypes, and specific virulence genes and contained more virulence genes (median, 10 versus 6: P < 0.001). In multivariable models, phylogenetic group B2, hlyD (hemolysin), cnf1 (cytotoxic necrotizing factor), iroN (siderophore receptor), ompT (outer membrane protease), and malX (pathogenicity island marker) most strongly predicted urine source. These findings challenge the fecal-urethral and prevalence hypotheses for FUTI pathogenesis and instead strongly support the possibility of alternate infection routes in some men and the special pathogenicity hypothesis. They also identify specific bacterial traits as potential targets for anti-FUTI interventions.Escherichia coli is a major extraintestinal pathogen, causing tremendous morbidity, mortality, and increased health care costs (33). Urinary tract infection (UTI), the principal extraintestinal syndrome caused by E. coli, although most common among women, is also a significant problem among men, who can experience cystitis, pyelonephritis, acute and chronic prostatitis, and febrile UTI (FUTI) (23,24,41). Better understanding of the pathogenesis of UTI in men is needed to guide the development of effective preventive measures.It is unknown whether in men with UTI the causative E. coli strains usually derive immediately from the host's own intestinal flora, as is true in females, according to the "fecal-urethral" hypothesis (9, 44). For example, vaginal or anal intercourse may introduce microorganisms directly into a man's urethra from his sex partner's vaginal or rectal flora, without involving his intestinal tract (2,3,8,43). Likewise, it is not known whether the particular E. coli strains that cause UTI in men do so merely because of their high prevalence within the host's intestinal flora, consistent with the "prevalence" hypothesis for UTI pathogenesis (38), or instead because they possess an enhanced ability to cause extraintestinal disease compared with other E. coli strains, consistent with the "special pathogenicity" hypothesis that is thought to underlie UTI pathogenesis in most females (27,30). Although the virulence factors (VF) and surface antigens of E. coli isolates from men with febrile UTI and prostatitis exhibit many similarities to those of strains causing pyelonephritis in women and girls, consi...

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The homogeneity of the faecal coliform flora of normal school-girls, characterized by serological and biochemical properties

Cited by 68 publications

References 18 publications

Molecular Epidemiology and Phylogenetic Distribution of the Escherichia coli pks Genomic Island

Molecular Epidemiology and Phylogenetic Distribution of the Escherichia coli pks Genomic Island

Identification of Urovirulence Traits inEscherichia coliby Comparison of Urinary and RectalE. coliIsolates from Dogs with Urinary Tract Infection

Phylogenetic and Pathotypic Comparison of Concurrent Urine and RectalEscherichia coliIsolates from Men with Febrile Urinary Tract Infection

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