Comparison of Diagnostic Techniques forHelicobacter cetorumInfection in Wild Atlantic Bottlenose Dolphins (Tursiops truncatus)

Abstract

Helicobacter cetorum sp. nov. has been cultured from the stomach of Atlantic white-sided dolphins (Lagenorhynchus acutus) and the feces of Pacific white-sided (L. obliquidens) and Atlantic bottlenose (Tursiops truncatus) dolphins and a beluga whale (Delphinapterus leucas). H. cetorum has high homology to Helicobacter pylori as shown by 16S rRNA sequencing, and H. cetorum infection has been associated with gastritis and clinical signs in cetaceans. Because the prevalence of H. cetorum in wild populations is unknown, minimally invasive techniques for detecting H. cetorum were compared for 20 wild bottlenose dolphins sampled as part of a long-term health study. Fecal samples were tested for helicobacter by culture, Southern blotting, and PCR using genus-specific and H. cetorum-specific primers. An enzyme-linked immunosorbent assay (ELISA) was developed to measure H. cetorum immunoglobulin G (IgG). H. cetorum was cultured from 4 of 20 fecal samples, 7 samples were positive using Helicobacter sp. PCR, and 8 samples were positive for H. cetorum using speciesspecific primers. Two additional fecal samples were positive by Helicobacter sp. Southern blotting, suggesting infection with another helicobacter. All 20 sera contained high levels of IgG antibodies to H. cetorum that were significantly lowered by preabsorption of the sera with whole-cell suspensions of H. cetorum (P < 0.02). Until the specificity of the serum ELISA can be determined by testing sera from dolphins confirmed to be uninfected, PCR and Southern blot screenings of feces are the most sensitive techniques for detection of H. cetorum, and results indicate there is at least a 50% prevalence of H. cetorum infection in these dolphins.

Diagnostic Accuracy of PCR-Based Detection Tests for Helicobacter Pylori in Otitis Media: A Meta-Analysis

“…However, the serology and histologic identification are not fast and reliable enough [29][30][31][32][33].The PCR-based molecular diagnostic techniques have been used for testing H. Pylori infections for about a decade [34,35]. Our meta-analysis revealed some concerns using the available evidences, which basically reflects the experience with PCR-based molecular diagnosis of H. Pylori infection among patient with OME, including the limitation of available evidences and a considerable variability among the available studies.…”

Comparison of Helicobacter spp. genetic sequences in wild and captive seals, and gulls

“…to infect a broad range of terrestrial hosts (Solnick & Schauer 2001), it is surprising that H. cetorum was detected in seals housed in facilities (namely AQWA and UWW) devoid of either dolphins or whales. Therefore, providing that the occurrence of such organisms was not a factor of captivity, it would seem plausible that alternative modes of transmission to the horizontal pathway proposed by Harper et al (2003a) may also be important in the dissemination of Helicobacter species amongst the marine host.…”

“…Species different to those previously characterized from terrestrial mammals have also been reported from the stomach and feces of marine mammals including dolphins, whales, harp seals and sea otters (Harper et al 2002(Harper et al , 2003a. Whilst many Helicobacter spp.…”

“…In some instances, this may also involve an intermediate host (such as birds) which may act as a reservoir for its dispersal (Walderström et al 2003). Although it has been suggested that similar processes may exist for marine mammals (Harper et al 2003a), the mode/s of transmission in these animals is unknown.…”

“…to infect a broad range of terrestrial hosts (Solnick & Schauer 2001), it is surprising that H. cetorum was detected in seals housed in facilities (namely AQWA and UWW) devoid of either dolphins or whales. Therefore, providing that the occurrence of such organisms was not a factor of captivity, it would seem plausible that alternative modes of transmission to the horizontal pathway proposed by Harper et al (2003a) may also be important in the dissemination of Helicobacter species amongst the marine host.That alternative modes of transmission may be important in the dissemination of Helicobacter species amongst vertebrate groups has been reported for species such as H. canadensis, where geese were reported as a reservoir for its transmission to humans (Walderström et al 2003). Within the current study, Helicobacter was also detected in a sample containing the feces of several wild silver gulls.…”