Identification of Non- Helicobacter pylori Spiral Organisms in Gastric Samples from Humans, Dogs, and Cats

Abstract

Tightly coiled bacteria are a rare cause of gastric pathology in humans and represent a mixture of species for which a zoonotic origin is suspected. Similar organisms are common inhabitants of the gastric mucosae of carnivores and pigs. It was the goal of the present study to determine the actual occurrence of each individual Helicobacter species in human, canine, and feline stomachs in order to better understand the possible zoonotic significance. Gastric biopsy samples from humans with histological evidence of non-Helicobacter pylori spiral bacteria (n ‫؍‬ 123) and samples from the gastric antrum, corpus, and cardia from dogs (n ‫؍‬ 110) and cats (n ‫؍‬ 43) were subjected to a multiplex PCR, enabling the identification of Helicobacter felis, Helicobacter bizzozeronii, Helicobacter salomonis, and "Candidatus Helicobacter suis." A PCR for detecting H. pylori was applied to all human samples. Single infections with "Candidatus Helicobacter suis," H. felis, H. bizzozeronii, H. salomonis, a hitherto unknown genotype of a non-H. pylori spiral organism (Helicobacter-like organism 135 [HLO135]), and H. pylori were identified in 30.9%, 8.9%, 2.4%, 11.4%, 7.3%, and 8.9% of the human biopsy samples, respectively. Mixed infections (16.3%) with two or even three of these were also found. In the canine stomach, H. bizzozeronii (70.0%) was encountered as the main spiral organism, while H. felis (62.7%) and HLO135 (67.4%) were the predominant Helicobacter species found in the feline gastric mucosa. Although the majority of human non-H. pylori organisms are Helicobacter species naturally occurring in the stomachs of pigs, cats, and dogs, the frequent identification of H. salomonis in human gastric biopsy samples is in contrast to its rare identification in pet carnivore samples, urging us to suspect other sources of infection. Spiral organisms have been described in the gastric mucosae of cats and dogs since the 19th century and are considered common inhabitants of the gastric mucosal niche (18). Three different morphological types were identified after ultrastructural analyses of the bacteria in situ; these types originally were presumed to represent various stages in the movement of one organism (25). Recent polyphasic taxonomy studies involving various isolates, however, revealed at least three different species belonging to the genus Helicobacter, namely, Helicobacter felis (24), Helicobacter bizzozeronii (17), and Helicobacter salomonis (21); these species are both phenotypically and phylogenetically highly related (21). These tightly coiled organisms were largely ignored by the scientific community until the isolation of Helicobacter pylori from the human gastric mucosa renewed interest in gastric bacteria (27).H. pylori, colonizing the stomachs of half of the world's human population, was proved to be the primary cause of gastritis and peptic ulceration (13) and is considered a major risk factor in the development of gastric adenocarcinoma (32) and mucosa-associated lymphoid tissue lymphoma (36). A limited number of hum...

Detection of Helicobacter spp. in the saliva of dogs with gastritis

“…of people in developing countries and 30% of people in developed countries (Downsett and Kowolik 2003, Bulck et al 2005, Agüloǧlu et al 2006, Chung et al 2014. A similar occurrence of the microorganism has been reported in companion animals.…”

“…Studies assessing the prevalence of various species of Helicobacter in the canine stomach seem to confirm this finding. The most common species identified in Finland, the United States and Belgium is Helicobacter bizzozeronii (Jalava et al 1997, Priestnall et al 2004, Bulck et al 2005. Helicobacter salomonis is the most commonly found species in Sweden (Ekman et al 2013), while Helicobacter heilmannii is the most recognized species in Poland, Portugal and South Korea (Hwang et al 2002, Kubiak 2006, Amorim et al 2015.…”

“…Helicobacter spp. was found in 67-86% of clinically healthy dogs, in 61-100% of animals with chronic vomiting and in 100% of laboratory beagle dogs and dogs from shelters (Henry et al 1987, Eaton et al 1996, Hwang et al 2002, Bulck et al 2005, Amorim et al 2015. Despite the high prevalence of the microorganism, its transmission, including human-human, animal-human, human-animal and animal-animal paths, remains unclear (Recordati et al 2007, Ekman et al 2013.…”

Genotyping pattern of the vacuolating cytotoxin A and cytotoxin associated gene A of the Helicobacter pylori strains detected in fecal samples of household dogs

“…15,16 Similar findings have been reported previously from Thailand, 17 Iran, 6 Denmark, 18 Egypt, 5 Italy 4 and Belgium. 19 Prevalence rate of H. pylori in fecal samples of our investigation (8.66%) was lower that of Thailand (17.30%). 20 Recent researches reported the high prevalence of Helicobacter-like microorganism in clinical samples taken from canine.…”

Detection of Helicobacter pylori in Drinking Water by Loop-Mediated Isothermal Amplification

“…other than H. pylori in the water samples. Poor sanitation of water and allowing domestic animals, which could be a carrier of non-pylori Helicobacter species to roam near water supplies, lead to water contamination (48)(49)(50)(51)(52). Another probability is the presence of H. pylori that has lost its pathogenicity genes (53).…”