Discovery of Disseminated J96‐like Strains of UropathogenicEscherichia coliO4:H5 Containing Genes for Both PapGJ96(Class I) and PrsGJ96(Class III) Gal(α1–4)Gal‐Binding Adhesins

Johnson, James R.; Russo, Thomas A.; Scheutz, Flemming; Brown, Jennifer; Zhang, Lixin; Palin, Karen; Rode, Christopher K.; Bloch, Craig A.; Marrs, Carl F.; Foxman, Betsy

doi:10.1086/514006

Cited by 70 publications

(79 citation statements)

References 3 publications

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“…The model pathogen CP9 is an E. coli blood isolate cultured from a patient with sepsis and has been previously described in detail (19,39). CP9 possesses many of the characteristics of typical ExPEC strains (40) and is highly virulent in a urinary tract infection model (36), an intraperitoneal infection model (42), and a pneumonia model (35,43).…”

Section: Methodsmentioning

confidence: 99%

E. colivirulence factor hemolysin induces neutrophil apoptosis and necrosis/lysis in vitro and necrosis/lysis and lung injury in a rat pneumonia model

Russo¹,

Davidson²,

Genagon³

et al. 2005

American Journal of Physiology-Lung Cellular and Molecular Phys

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In this study a wild-type extraintestinal pathogenic strain of E. coli (ExPEC)(CP9) and isogenic derivatives deficient in hemolysin (Hly) and cytotoxic necrotizing factor (CNF) were assessed in vitro and in a rat model of gram-negative pneumonia to test the hypothesis that these virulence factors induce neutrophil apoptosis and/or necrosis/lysis. As ascertained by in vitro caspase-3/7 and LDH activities and neutrophil morphology, Hly mediated neutrophil apoptosis at lower E. coli titers (1 ϫ 10 5-6 cfu) and necrosis/lysis at higher titers (Ն1 ϫ 10 7 cfu). Data suggest that CNF promotes apoptosis but not necrosis or lysis. We also demonstrate that annexin V/7-amino-actinomycin D staining was an unreliable assessment of apoptosis using live E. coli. The use of caspase-3/7 and LDH activities and neutrophil morphology supported the notion that necrosis, not apoptosis, was the primary mechanism by which neutrophils were affected in our in vivo gram-negative pneumonia model using live E. coli. In addition, in vivo studies demonstrated that Hly mediates lung injury. Neutrophil necrosis was not observed when animals were challenged with purified lipopolysaccharide, demonstrating the importance of using live bacteria. These findings establish that Hly contributes to ExPEC virulence by mediating neutrophil toxicity, with necrosis/ lysis being the dominant effect of Hly on neutrophils in vivo and by lung injury. Whether Hly-mediated lung injury is due to neutrophil necrosis, a direct effect of Hly, or both is unclear.Escherichia coli; gram-negative bacilli; cytotoxic necrotizing factor-1 NOSOCOMIAL PNEUMONIA ACCOUNTS for 15% of hospital-acquired infections (2). Gram-negative enteric bacilli such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter sp., Acinetobacter, and Stenotrophomonas are the most common cause of hospital-acquired pneumonia, being implicated in 55-85% of cases (8 -10, 24). Severe disease usually occurs when these agents cause pneumonia, with associated crude mortality and estimated attributable mortality ranging from 24 to 76% and 20 to 50%, respectively, which translates into 36,000 -80,000 deaths annually (2, 8, 24, 52). Over the last 10 -15 years, there has been little improvement in the outcome from this infection. The estimated annual cost of nosocomial pneumonias alone due to gram-negative bacilli in this country is greater than one billion dollars (55).A goal of our laboratory is to identify strategies to decrease the morbidity and mortality caused by gram-negative pneumonia. To accomplish this, we have been studying neutrophil-pathogen interactions in a rat model of bacterial pneumonia, using E. coli as a model pathogen (37,38,43). The importance of neutrophils in protecting against infection in the lung is as great as any other site in the body (46). Increased susceptibility and severity of pneumonia occur in the setting of neutropenia and with genetically inherited (e.g., chronic granulomatous disease) or drug-induced (e.g., steroids) disorders of neutrophil function...

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Section: Methodsmentioning

confidence: 99%

E. colivirulence factor hemolysin induces neutrophil apoptosis and necrosis/lysis in vitro and necrosis/lysis and lung injury in a rat pneumonia model

Russo¹,

Davidson²,

Genagon³

et al. 2005

American Journal of Physiology-Lung Cellular and Molecular Phys

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“…The E. coli Reference (ECOR) collection has been described elsewhere (12,14,35). The human clinical E. coli isolates CA10, V32, 536, BOS02, and IA2 were described previously (2,5,17,20,24,33).…”

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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“…Notably, 29 of the 30 IEKC reference set isolates fell within these four cells, i.e., they exhibited precise genotype-phenotype concordance. The sole exception was strain J96, which although previously reported to express the (group 2) K6 antigen (8), contains group 3 kps sequences and is capsule minus according to the IEKC (19).…”

mentioning

confidence: 99%

Detection of the Escherichia coli Group 2 Polysaccharide Capsule Synthesis Gene kpsM by a Rapid and Specific PCR-Based Assay

Johnson

O'Bryan

2004

J Clin Microbiol

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A rapid and simple PCR-based assay for detection of the group 2 capsule synthesis gene kpsM of Escherichia coli was designed and validated. When combined with the published group 2 primers (kpsIIf, 5-GCGCATT TGCTGATACTGTTG-3; kpsIIr, 5-CATCCAGACGATAAGCATGAGCA-3), the new primers (the kpsIIf primer and a new reverse primer K2r, 5-AGGTAGTTCAGACTCACACCT-3) allowed specific identification by exclusion of the heretofore elusive K2 kpsM variant. The primers yielded the predicted amplicon when multiplexed with other primers and used under varied assay conditions, including a range of concentrations of individual reaction mixture ingredients and of annealing temperatures (from 54 to 64°C).

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Discovery of Disseminated J96‐like Strains of UropathogenicEscherichia coliO4:H5 Containing Genes for Both PapG_J96(Class I) and PrsG_J96(Class III) Gal(α1–4)Gal‐Binding Adhesins

Cited by 70 publications

References 3 publications

E. colivirulence factor hemolysin induces neutrophil apoptosis and necrosis/lysis in vitro and necrosis/lysis and lung injury in a rat pneumonia model

E. colivirulence factor hemolysin induces neutrophil apoptosis and necrosis/lysis in vitro and necrosis/lysis and lung injury in a rat pneumonia model

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

Detection of the Escherichia coli Group 2 Polysaccharide Capsule Synthesis Gene kpsM by a Rapid and Specific PCR-Based Assay

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