Description of Campylobacter curvus and C. curvus -Like Strains Associated with Sporadic Episodes of Bloody Gastroenteritis and Brainerd's Diarrhea

Abstract

Campylobacter curvus is a rarely encountered Campylobacter species in human, animal, and environmental samples. During the course of two investigations, one involving a search for possible bacterial agents causing bloody gastroenteritis and a second concerning a small outbreak of Brainerd's diarrhea in northern California, 20 strains of C. curvus or C. curvus-like organisms were isolated by a microfiltration technique and prolonged incubation. The results suggest that C. curvus may be an underappreciated Campylobacter that may be involved in sporadic and outbreak cases of bloody or chronic diarrhea in humans.The genus Campylobacter consists of curved or S-shaped gram-negative, oxidase-positive microaerophilic bacilli with a respiratory type of metabolism (15). The genus has undergone several taxonomic revisions over the past decade, including the transfer of a number of species to either the genus Arcobacter or the genus Helicobacter (12). Sixteen species presently reside in the genus Campylobacter. Of these 16 species, Campylobacter jejuni, C. coli, and C. fetus are the major species of medical, public health, or veterinary interest involved in disease processes (12).Of the 13 remaining Campylobacter species, very little information regarding their pathogenicity is available, although some species, such as C. upsaliensis, C. hyointestinalis, and C. lari, have been associated with various infectious syndromes (1, 3, 13). Even less information about campylobacters such as C. curvus is available. Originally described in 1984 ("Wolinella curva") (14), only four strains of C. curvus were described in that report; two strains were associated with the oral cavity, one isolate was from blood, and the fourth was a clinical isolate of unknown origin. Since that initial report, few studies have reported on the isolation of C. curvus. C. curvus has been isolated from the stools of patients who subsequently presented with either Guillain-Barré or Fisher's syndrome, although no role in the development of these neurologic conditions could be associated with this species (8). In a 2000 study of more than 1,300 human stool specimens conducted to study the prevalence of campylobacters (other than C. jejuni and C. coli), only 3 of 48 campylobacters recovered were tentatively identified as C. curvus-like (4). A study from 2003 (11) reported that 320 consecutive liquid or semisolid fecal specimens submitted to a laboratory for enteric pathogen detection were culture negative for C. curvus, although one stool specimen was positive for C. curvus by 16S rRNA gene PCR. These cumulative results suggest that the frequency of C. curvus in the gastrointestinal tracts of symptomatic individuals is exceedingly low.Over a 4-year period, we have isolated 20 strains of C. curvus from two separate and distinct clinical settings, namely, from a hospital survey of infectious causes of bloody diarrhea and from an outbreak of Brainerd's diarrhea in northern California. These isolations serve as the basis of this report. MATERIALS AND METHODSSettings...

Gastroenteritis caused by Campylobacter concisus

“…The obtained consensus sequence was submitted to the GenBank using the BLASTN tool (http://www.ncbi.nlm.nih.gov/). Highest similarity was found with a number of strains designated Campylobacter curvus from one study (Abbott et al, 2005), and with some C. concisus type or culture collection strains (98.9-99.8 % identity). However, there was less identity with C. curvus type or culture collection strains (,95 %).…”

“…The species most commonly associated with human infection are Campylobacter jejuni and Campylobacter coli. Other Campylobacter species are also known to cause human infections (Abbott et al, 2005;Blaser & Allos, 2005;Chua et al, 2007;Vandamme et al, 1989). Many of these non-jejuni, non-coli campylobacters may play a greater role in causing human and animal disease than previously recognized (Blaser & Allos, 2005;Lastovica & Skirrow, 2000;Maher et al, 2003).…”

Campylobacter curvus -Associated Hepatic Abscesses: a Case Report

“…The species has been isolated from the blood (6) and the oral cavity, although it is noninvasive orally and is not believed to be a causative agent of periodontal disease (7,15). Although not well documented, the gastrointestinal tract has also been shown previously to be a reservoir for this species (1,9) and is a far more likely source in this case than the well-documented oral cavity (7,15,18).…”

“…This may explain the difficulties found in culturing and maintaining C. curvus in a laboratory setting. Several species, including C. curvus, do not respond well to conventional isolation methods and, therefore, may remain undetected, particularly if present in conjunction with another Campylobacter species that may be cultured under microaerobic conditions unsuitable for C. curvus (1,9,16,17). Based on our results, this organism is likely being under-reported due to both selective media and unfavorable growth conditions (13).…”

“…Wolinella succinogenes results were identical in all tests except for the indoxyl acetate test, in which the result was negative. more pathogenic than originally believed (1,6). Selective media for Campylobacter usually contains antibiotics to which species other than C. jejuni, C. coli, and C. lari are susceptible (13).…”