Survival of Helicobacter pylori in ready-to-eat foods at 4 degrees C

Role of Oral Yeast in Replenishing Gastric Mucosa with Yeast and Helicobacter pylori

The relationship between oral and gastric yeasts and their role in the colonization of Helicobacter pylori in the stomach was studied. Four groups of 221, 7, 44, and 10 patients were used for the isolation of H. pylori and oral and gastric yeasts. In Group 1, gastric biopsies were used for the isolation of H. pylori and yeast, rapid urease test (RUT), staining with Gram's and hematoxylin & eosin (H&E), and immunohistochemistry (IHC) methods. In the other three groups, DNAs extracted from H. pylori and yeasts were used for the amplification of H. pylori-specific genes. Wet mounts of yeasts in Group 2 were examined to observe intracellular bacteria and released EVs. Among 221 patients, 65 (29.3%) had oral yeast, 35 (15.8%) H. pylori, and 31 (14%) gastric yeast. Culture of oral yeasts showed a significant correlation with the detection of H. pylori by IHC (10.3%), Gram stain (9%), RUT (6.3%), H&E (4.9%), and culture (4%) (p < 0.05). Gram-stained biopsies showed the occurrence of yeast and H. pylori, and the release of EVs from yeast. Detection of similar H. pylori genes in oral and gastric yeasts from patients in Group 2 showed their common source. Oral yeasts in Groups 3 and 4 also carried H. pylori genes. Wet mount preparations of yeasts showed intracellular bacteria inside the yeast vacuole and the release of EVs that could carry H. pylori. Oral yeast protects its intracellular H. pylori and releases it inside EVs to safely reach gastric mucosa. Yeast, as the environmental reservoir of H. pylori, plays a crucial role in bacterial reinfection after successful eradication.

Clarithromycin-, and metronidazole-resistant Helicobacter pylori isolated from raw and ready-to-eat meat in Mansoura, Egypt

Helicobacter pylori (H. pylori), classified as a class-I carcinogen, is one of the leading medical pathogens of global concern associated mainly with the development of gastric adenocarcinomas and gastric mucosa-associated lymphoid tissue lymphomas; nevertheless, its prevalence in food especially meat and meat products is not fully covered. Additionally, the resistance of H. pylori towards clarithromycin is increasing worldwide and consider the leading cause of H. pylori treatment failure. Thus, the present study was designed to determine the prevalence, molecular characterization, and antimicrobial resistance profiles of clarithromycin-, and metronidazole-resistant H. pylori isolated from raw and ready-to-eat meat samples retailed in Mansoura city, Egypt. Among the 250 samples tested, H. pylori were molecularly confirmed in 40.8 % (49/120) of raw meat products and in 29.2 % (38/130) of ready-to-eat meat products. Precisely, 53.3 % (32/60), 56.7 % (17/30), 40 % (8/20), 55 % (11/20), 60 % (12/20), 13.3 % (4/30), and 15 % (3/20) of raw ground beef, beef burger, beef burger sandwiches, beef shawarma sandwiches, beef kofta sandwiches, beef luncheon, and beef sausage sandwiches, respectively were positive for H. pylori. Of the 204 biochemically-identified H. pylori isolates, 53.9 % (110/204) were molecularly confirmed by PCR through the detection of glmM, cagA, or vacA genes, which were detected at an incidence of 95.5 % (105/110), 77.3 % (85/110), and 20.9 % (23/110) among the isolates, respectively. The antimicrobial sensitivity testing revealed that all of the 110 (100 %) molecularly-confirmed H. pylori isolates were multidrug-resistant (MDR; resistant to four or more antibiotics). Interestingly, 100 % and 61.8 % of H. pylori isolated from raw and ready-to-eat meat were resistant to metronidazole and clarithromycin, respectively which consider alarming results as metronidazole and clarithromycin are the mainstay antibiotics in the treatment of H. pylori infections. Additionally, 94.5 %, 94.5 %, 24.5 %, 23.6 %, and 13.6 % of isolates were resistant to vancomycin, sulphamethoxazole-trimethoprim, imipenem, levofloxacin, and nitrofurantoin, respectively. The widespread contamination of examined raw and ready-to-eat meat product samples with MDR H. pylori isolates could constitute a tremendous public health hazard. Further studies concerning the prevalence and possible methods of elimination of H. pylori in different food categories distributed in the various provinces in Egypt as well as in other countries is required for a better understanding the H. pylori as an emerging foodborne pathogen.

Transmission routes and patterns of helicobacter pylori

BACKGROUND AND OBJECTIVE

Helicobacter pylori (H. pylori), a gram-negative bacterium that colonizes the stomach, can cause chronic gastritis and peptic ulcers, as well as gastric cancer as a Class I carcinogen. However, the modes of H. pylori transmission are not clear. This review aims to clarify the transmission routes and patterns of H. pylori and identify efficacious prevention measures.

METHODS

Studies of H. pylori transmission were identified using PubMed, the Web of Science, and Cochrane Central; the retrieval deadline was October 2022.

RESULTS

The transmission routes of H. pylori are discussed, focusing on the five primary transmission routes, namely fecal-oral, oral-oral, gastric-oral, anal-oral, and genital-oral. We propose that H. pylori is contracted through multiple transmission routes. Additionally, we summarize the key transmission patterns of H. pylori, including person-to-person and animal-to-human transmission, as well as foodborne and occupational exposure.

CONCLUSION

Fecal-oral appears to be the most common H. pylori transmission routes. Although the oral-oral pathway is also important, the evidence does not support that this route of transmission is universal. The gastric-oral route occurs primarily in children and patients who are prone to vomiting. Meanwhile, the anal-oral and genital-oral routes remain hypothetical. Person-to-person and foodborne infections represent the predominant transmission patterns of H. pylori, whereas strong environmental and occupational limitations are associated with animal-to-human and occupational exposure.

Colonization of Helicobacter pylori in the oral cavity - an endless controversy?

Helicobacter pylori is associated with chronic gastritis, gastric or duodenal ulcers, and gastric cancer. Since the oral cavity is the entry port and the first component of the gastrointestinal system, the oral cavity has been discussed as a potential reservoir of H. pylori. Accordingly, a potential oral-oral transmission route of H. pylori raises the question concerning whether close contact such as kissing or sharing a meal can cause the transmission of H. pylori. Therefore, this topic has been investigated in many studies, applying different techniques for detection of H. pylori from oral samples, i.e. molecular techniques, immunological or biochemical methods and traditional culture techniques. While molecular, immunological or biochemical methods usually yield high detection rates, there is no definitive evidence that H. pylori has ever been isolated from the oral cavity. The specificity of those methods may be limited due to potential cross-reactivity, especially with H. pylori-like microorganisms such as Campylobacter spp. Furthermore, the influence of gastroesophageal reflux has not been investigated so far. This review aims to summarize and critically discuss previous studies investigating the potential colonization of H. pylori in the oral cavity and suggest novel research directions for targeting this critical research question.

Sugar-Rich Foods Carry Osmotolerant Yeasts with Intracellular Helicobacter Pylori and Staphylococcus spp

BACKGROUND Sugar-rich foods are of the main components of daily human meals. These foods with high sugar and low water content kill bacteria. However, osmotolerant yeasts survive and multiply. The aim of this study was to examine the occurrence of intracellular Helicobacter pylori (H. pylori) and Staphylococcus spp. in yeast isolates from sugar-rich foods. METHODS Thirty-two yeast isolates from fresh fruits, dried fruits, commercial foods, and miscellaneous foods were identified by the sequencing of amplified products of 26S rDNA. Fluorescence microscopy and LIVE/DEAD bacterial viability kit were used to examine the occurrence of live bacteria inside the yeast's vacuole. Immunofluorescence assay was used to confirm the identity of intracellular bacteria as H. pylori and Staphylococcus . Polymerase chain reaction (PCR) was used for the detection of 16S rDNA of H. pylori and Staphylococcus in the total DNA of yeasts. RESULTS Yeasts were identified as members of seven genera; Candida, Saccharomyces, Zygosaccharomyces, Pichia, Meyerozyma, Metschnikowia, and Wickerhamomyces. Intravacuolar bacteria were stained green with a bacterial viability kit, revealing that they were alive. Immunofluorescence assay confirmed the identity of intracellular H. pylori and Staphylococcus spp. PCR results revealed that among the 32 isolated yeasts, 53% were H. pylori -positive, 6% were Staphylococcus -positive, 18.7% were positive for both, and 21.8% were negative for both. CONCLUSION Detection of H. pylori - and Staphylococcus -16S rDNA in yeast isolates from dried fruits, and commercial foods showed the occurrence of more than one kind of endosymbiotic bacterium in yeasts' vacuoles. While the establishment of H. pylori and Staphylococcus in yeast is a sophisticated survival strategy, yeast serves as a potent bacterial reservoir.

Phenotypic and Genotypic Assessment of Antibiotic Resistance and Genotyping of vacA, cagA, iceA, oipA, cagE, and babA2 Alleles of Helicobacter pylori Bacteria Isolated from Raw Meat

BACKGROUND

Foodstuffs with animal origins, particularly meat, are likely reservoirs of Helicobacter pylori.

PURPOSE

An existing survey was accompanied to assess phenotypic and genotypic profiles of antibiotic resistance and genotyping of vacA, cagA, cagE, iceA, oipA, and babA2 alleles amongst the H. pylori bacteria recovered from raw meat.

METHODS

Six-hundred raw meat samples were collected and cultured. H. pylori isolates were tested using disk diffusion and PCR identification of antibiotic resistance genes and genotyping.

RESULTS

Fifty-two out of 600 (8.66%) raw meat samples were contaminated with H. pylori. Raw ovine meat (13.07%) had the uppermost contamination. H. pylori bacteria displayed the uppermost incidence of resistance toward tetracycline (82.69%), erythromycin (80.76%), trimethoprim (65.38%), levofloxacin (63.46%), and amoxicillin (63.46%). All H. pylori bacteria had at least resistance toward one antibiotic, even though incidence of resistance toward more than eight antibiotics was 28.84%. Total distribution of rdxA, pbp1A, gyrA, and cla antibiotic resistance genes were 59.61%, 51.92%, 69.23%, and 65.38%, respectively. VacA s1a (84.61%), s2 (76.92%), m1a (50%), m2 (39.13%), iceA1 (38.46%), and cagA (55.76%) were the most generally perceived alleles. S1am1a (63.46%), s2m1a (53.84%), s1am2 (51.92%), and s2m2 (42.30%) were the most generally perceived genotyping patterns. Frequency of cagA-, oipA-, and babA2- genotypes were 44.23%, 73.07%, and 80.76%, respectively. A total of 196 combined genotyping patterns were also perceived.

CONCLUSION

The role of raw meat, particularly ovine meat, in transmission of virulent and resistant H. pylori bacteria was determined. VacA and cagA genotypes had the higher incidence. CagE-, babA2-, and oipA- H. pylori bacteria had the higher distribution. Supplementary surveys are compulsory to originate momentous relations between distribution of genotypes, antibiotic resistance, and antibiotic resistance genes.

Helicobacter pylori: Survival in cultivable and non-cultivable form in artificially contaminated Mytilus galloprovincialis

Several studies report the presence of Helicobacter pylori (H. pylori) in seawater either free or attached to planktonic organism. After considering the role played by plankton in the food chain of most aquatic ecosystems and the possible role that seafood products can assume in the transmission of H. pylori to humans, the aim of this study was to assess the survival of H. pylori in artificially contaminated Mytilus galloprovincialis (M. galloprovincialis). A traditional culture method and a reverse transcriptase-PCR (RT-PCR) assay were employed to detect the mRNA of known virulence factor (VacA) which can be considered use a marker of bacterial viability. The obtained results clearly show that H. pylori is able to survive in artificially contaminated mussels for 6 days (2 days in a cultivable form and 4 days in a non-cultivable form).

Phenotypic analysis of antibiotic resistance and genotypic study of the vacA, cagA, iceA, oipA and babA genotypes of the Helicobacter pylori strains isolated from raw milk

Background

Foods with animal origins and particularly milk play a considerable role in transmission of Helicobacter pylori. The current study was performed to assess phenotypic characters of antibiotic resistance and genotyping pattern of vacA, cagA, iceA, oipA and babA2 alleles amongst the H. pylori strains isolated from raw milk.

Methods

Six-hundred and thirty raw milk samples were collected and cultured on Wilkins Chalgren anaerobe media. Antibiotic resistance and genotyping patterns were studied using disk diffusion and PCR, respectively.

Results

Sixty-seven out of 630 (10.63%) raw milk samples were positive for H. pylori. Ovine raw milk (17.27%) samples had the highest prevalence of H. pylori, while camel (5.00%) had the lowest. H. pylori strains harbored the highest prevalence of resistance against ampicillin (82.08%), tetracycline (76.11%), amoxicillin (74.62%), metronidazole (65.67%) and erythromycin (53.73%). Prevalence of resistance against more than 10 types of antibiotics was 17.91%. VacA s1a (83.58%), m1a (80.59%), s2 (77.61%) and m2 (68.65%), cagA (73.13%) and babA2 (44.77%) were the most commonly detected genotypes. We found that S1am1a (56.71%), s2m1a (56.71%), s1 am2 (43.28%) and s2 m2 (43.28%) were the most commonly detected genotyping pattern. Frequency of cagA-, oipA- and babA2- genotypes were 26.86%, 62.68% and 55.22%, respectively. We found that S1a/cagA+/iceA1/oipA-/babA2- (28.35%), m1a/cagA+/iceA1/oipA-/babA2- (28.35%) and s2/cagA+/iceA1/oipA-/babA2- (26.86%) were the most commonly detected combined genotyping pattern.

Conclusions

Simultaneous presence of vacA, cagA, iceA, oipA and babA2 genotypes in antibiotic resistant H. pylori strains indicates important public health issue regarding the consumption of raw milk. However, additional researches are required to find molecular genetic homology and other epidemiological aspects of H. pylori in milk.

Occurrence of cagA+ vacA s1a m1 i1 Helicobacter pylori in farm animals in Egypt and ability to survive in experimentally contaminated UHT milk

Cases of human gastric cancer due to Helicobacter pylori have been reported worldwide and animals might act as a reservoir of infection in certain circumstances. The recent few decades showed a rapid decline in the incidence of gastric cancer, which was mainly due to the decrease in H. pylori infection. The aims of the present study were to determine the prevalence of H. pylori among livestock and investigate whether the animal isolates can be transmitted through contaminated milk causing gastric infection. Feces and milk samples were collected from apparently healthy cows, buffaloes, and sheep, and were examined by nested PCR and genotyping. The PCR positive samples were further subjected to bacterial culture followed by partial 16s sequencing of the isolates. Twenty-nine percent of the animals showed the presence of H. pylori, mainly the virulent cagA+vacA+s1a m1 i1 genotype, which is known to be associated with serious diseases in humans. The spiral viable culturable form (SVCF) of this strain was inoculated into UHT (ultra-high temperature) milk and remained viable for up to 10 days at 4 °C. Increasing period of storage and or temperature led to a decrease in the number of the SVCF and occurrence of the coccoid viable non-culturable form (CVNCF). The infectivity of the survived forms was determined by feeding healthy groups of laboratory mice with the contaminated UHT milk containing SVCF or CVNCF for 40 days. The gastric mucosa of the two mice groups showed similar levels of H. pylori load. This highlights that H. pylori can persist in contaminated milk by entering a non-culturable state, which can induce gastric infection.

Helicobacter pylori: A foodborne pathogen?

Helicobacter pylori (H. pylori) is an organism that is widespread in the human population and is sometimes responsible for some of the most common chronic clinical disorders of the upper gastrointestinal tract in humans, such as chronic-active gastritis, duodenal and gastric ulcer disease, low-grade B-cell mucosa associated lymphoid tissue lymphoma of the stomach, and gastric adenocarcinoma, which is the third leading cause of cancer death worldwide. The routes of infection have not yet been firmly established, and different routes of transmission have been suggested, although the most commonly accepted hypothesis is that infection takes place through the faecal-oral route and that contaminated water and foods might play an important role in transmission of the microorganism to humans. Furthermore, several authors have considered H. pylori to be a foodborne pathogen because of some of its microbiological and epidemiological characteristics. H. pylori has been detected in drinking water, seawater, vegetables and foods of animal origin. H. pylori survives in complex foodstuffs such as milk, vegetables and ready-to-eat foods. This review article presents an overview of the present knowledge on the microbiological aspects in terms of phenotypic characteristics and growth requirements of H. pylori, focusing on the potential role that foodstuffs and water may play in the transmission of the pathogen to humans and the methods successfully used for the detection of this microorganism in foodstuffs and water.

Natural fruits, flowers, honey, and honeybees harbor Helicobacter pylori-positive yeasts

BACKGROUND

For controlling Helicobacter pylori infection in humans, its environmental reservoir should be determined. In this study, yeast isolates from an isolated village in Iran were studied for the intracellular occurrence of H. pylori.

MATERIALS AND METHODS

In this study, yeasts were isolated from 29 samples, including oral swabs from villagers (n = 7), flowers and fruits (n = 6), honey and honeybees (n = 12) and miscellaneous samples (4). Yeasts were classified into 12 RFLP groups and identified by amplification of 26S rDNA and sequencing. DNA extracted from the yeast cells was examined for the presence of H. pylori using PCR.

RESULTS

Of the 29 yeasts, 27 were members of different genera of Ascomycete. H. pylori was detected in 5 of 9 Candida (55.5%), 4 of 5 Komagataella (80%), 3 of 4 Pichia (100%), 2 of 2 Cytobasidia (100%), 2 of 2 Hansenia (100%), 1 of 1 Meyerozyma (100%) and 2 of 3 not sequenced (66.6%) yeasts. Distribution of 19 of 29 (65.5%) H. pylori-positive yeasts within 4 groups was as follows: 1 of 7(14.3%) in oral swabs, 5 of 6 (83.3%) in flowers and fruits, 10 of 12 (83.3%) in honey and the bee group and 3 of 4 (75%) in miscellaneous.

CONCLUSIONS

Different genera of osmotolerant yeasts from flowers, fruits, honey, and honeybees contained H. pylori in their vacuole. High frequency of H. pylori-positive yeasts in these samples might be related to their high sugar content. Insects such as honeybees that facilitate transfer and easy access of these yeasts to nectars serve as the main reservoirs of these yeasts, playing an important role in their protection and dispersal. Accordingly, H. pylori inside these yeasts can be carried by honeybees to different sugar- and nutrient-rich environments. Sugar-rich environments and honeybees play an important role in distribution of H. pylori-positive yeasts in nature.

Biofilm formation enhances Helicobacter pylori survivability in vegetables

To date, the exact route and mode of transmission of Helicobacter pylori remains elusive. The detection of H. pylori in food using molecular approaches has led us to postulate that the gastric pathogen may survive in the extragastric environment for an extended period. In this study, we show that H. pylori prolongs its survival by forming biofilm and micro-colonies on vegetables. The biofilm forming capability of H. pylori is both strain and vegetable dependent. H. pylori strains were classified into high and low biofilm formers based on their highest relative biofilm units (BU). High biofilm formers survived longer on vegetables compared to low biofilm formers. The bacteria survived better on cabbage compared to other vegetables tested. In addition, images captured on scanning electron and confocal laser scanning microscopes revealed that the bacteria were able to form biofilm and reside as micro-colonies on vegetable surfaces, strengthening the notion of possible survival of H. pylori on vegetables for an extended period of time. Taken together, the ability of H. pylori to form biofilm on vegetables (a common food source for human) potentially plays an important role in its survival, serving as a mode of transmission of H. pylori in the extragastric environment.

Detection of Helicobacter pylori glmM gene in bovine milk using Nested polymerase chain reaction

Aim:

The aim was to detect the glmM gene of Helicobacter pylori (H. pylori) in cow’s milk from different dairy farms in Khartoum State using Nested polymerase chain reaction (PCR).

Materials and Methods:

A total of 50 milk samples were collected from different dairy farms in Khartoum State (13 from Khartoum, 24 Khartoum North, and 13 from Omdurman Provinces).

Results:

The generated results showed that 11/50 (22%) were harboring the investigated H. pylori glmM gene in Khartoum State (1/13 [7.7%] Khartoum, 9/24 [37.5%] Khartoum North, and 1/13 [7.7%] Omdurman provinces, respectively).

Conclusion:

To the best of our knowledge, this was the first report on the detection of H. pylori glmM gene in cattle milk in Khartoum State. Nonetheless, the high percentages of H. pylori DNA detection in milk opened new avenues toward exploring the risk of human infection with H. pylori through the consumption of raw milk.

Helicobacteraceae in Bulk Tank Milk of Dairy Herds from Northern Italy

Helicobacter pylori is responsible for gastritis and gastric adenocarcinoma in humans, but the routes of transmission of this bacterium have not been clearly defined. Few studies led to supposing that H. pylori could be transmitted through raw milk, and no one investigated the presence of other Helicobacteraceae in milk. In the current work, the presence of Helicobacteraceae was investigated in the bulk tank milk of dairy cattle herds located in northern Italy both by direct plating onto H. pylori selective medium and by screening PCR for Helicobacteraceae, followed by specific PCRs for H. pylori, Wolinella spp., and “Candidatus Helicobacter bovis.” Three out of 163 bulk milk samples tested positive for Helicobacteraceae, but not for the subsequent PCRs. H. pylori was not isolated in any case. However, given similar growth conditions, Arcobacter butzleri, A. cryaerophilus, and A. skirrowii were recovered. In conclusion, the prevalence of Helicobacteraceae in raw milk was negligible (1.8%), and H. pylori was not identified in any of the positive samples, suggesting that, at least in the farming conditions of the investigated area, bovine milk does not represent a potential source of infection.

Virulence factors and antibiotic resistance of Helicobacter pylori isolated from raw milk and unpasteurized dairy products in Iran

BACKGROUND

Despite the high importance of Helicobacter pylori, the origin and transmission of this bacterium has not been clearly determined. According to controversial theories and results of previous studies, animal source foods - especially milk - play an important role in the transmission of H. pylori to humans. The aim of the present study was to determine the distribution of vacA, cagA, iceA and oipA virulence factors in H. pylori strains isolated from milk and dairy products and study their antimicrobial resistance properties.

METHODS

A total of 520 raw milk and 400 traditional dairy product samples were cultured and tested. Those that were H. pylori-positive were analyzed for the presence of vacA, cagA, iceA and oipA virulence factors. Antimicrobial susceptibility testing was performed by the disk diffusion method.

RESULTS

One hundred and three out of 520 milk samples (19.8%) and 77 out of 400 dairy products samples (19.2%) were contaminated with H. pylori. The most frequently contaminated samples were ovine milk (35%) and traditional cheese (30%). Total prevalence of vacA, cagA, iceA and oipA factors were 75%, 76.6%, 41.6% and 25%, respectively. H. pylori strains of milk and dairy products harbored high levels of resistance to ampicillin (84.4%), tetracycline (76.6%), erythromycin (70.5%) and metronidazole (70%).

CONCLUSIONS

High presence of antibiotic-resistant strains of H. pylori suggest that milk and dairy samples may be the sources of bacteria that can cause severe infection. Our findings should raise awareness about antibiotic resistance in H. pylori strains in Iran.

Vacuoles of Candida yeast as a specialized niche for Helicobacter pylori

Helicobacter pylori (H. pylori) are resistant to hostile gastric environments and antibiotic therapy, reflecting the possibility that they are protected by an ecological niche, such as inside the vacuoles of human epithelial and immune cells. Candida yeast may also provide such an alternative niche, as fluorescently labeled H. pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric, oral, vaginal and foodborne Candida yeasts. In addition, H. pylori-specific genes and proteins were detected in samples extracted from these yeasts. The H. pylori present within these yeasts produce peroxiredoxin and thiol peroxidase, providing the ability to detoxify oxygen metabolites formed in immune cells. Furthermore, these bacteria produce urease and VacA, two virulence determinants of H. pylori that influence phago-lysosome fusion and bacterial survival in macrophages. Microscopic observations of H. pylori cells in new generations of yeasts along with amplification of H. pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H. pylori as part of their vacuolar content. Accordingly, it is proposed that yeast vacuoles serve as a sophisticated niche that protects H. pylori against the environmental stresses and provides essential nutrients, including ergosterol, for its growth and multiplication. This intracellular establishment inside the yeast vacuole likely occurred long ago, leading to the adaptation of H. pylori to persist in phagocytic cells. The presence of these bacteria within yeasts, including foodborne yeasts, along with the vertical transmission of yeasts from mother to neonate, provide explanations for the persistence and propagation of H. pylori in the human population. This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H. pylori to thrive in host cell vacuoles.

Detection of Helicobacter pylori in Various Types of Vegetables and Salads

Background:

There is a possibility for the presence of Helicobacter pylori in vegetables due to their close contact with polluted water, soil and feces.

Objectives:

This study was carried out to detect the presence of H. pylori in vegetables and salads in Iran.

Materials and Methods:

In total, 460 vegetable and salad samples were collected and transferred immediately to the laboratory. All samples were cultured and tested for the presence of H. pylori using the Polymerase Chain Reaction technique.

Results:

The results showed that 44 of 460 samples (9.56%) were positive for H. pylori using the culture method. The Polymerase Chain Reaction technique showed that 50 of 460 samples (10.86%) were positive for H. pylori. Un-washed leek, traditional salad, un-washed basil and un-washed lettuce were the most commonly contaminated samples. The presence of the bacteria in various vegetables was statistically significant (P < 0.05).

Conclusions:

Vegetables are a new source of H. pylori and accurate washing of vegetables improves such contaminations.

Survival of Helicobacter pylori in Turkish fermented sucuk and heat-treated sucuk during production

The aim of this study was to investigate the survival of Helicobacter pylori during production of sucuk (Turkish fermented sausage). The sucuk mixture was inoculated with H. pylori ATCC 43504 to produce a final level in the mixture of ∼5 × 10(6) CFU/g. Samples in group I were fermented and dried traditionally at 22°C for 7 days. Samples in groups II and III were subjected to the traditional fermentation at 22°C for 3 days. After fermentation, group II samples were fermented and dried at 35°C for 4 days and group III samples were treated with heat until the core temperature reached 65°C. On the first day of fermentation, a 1-log reduction in H. pylori was found in all groups. The H. pylori levels in all groups increased by about 1 log CFU/g by the third day of fermentation and reached the inoculation level. On the fifth and seventh days of fermentation, no appreciable change occurred in the level of H. pylori in groups I and II. After heat treatment, the H. pylori levels were below the level of detection. These results suggest that H. pylori can grow during sucuk fermentation and that a heat treatment should be used during sucuk processing to destroy H. pylori.

Detection of Helicobacter pylori in raw bovine milk by fluorescence in situ hybridization (FISH)

The transmission pathways of Helicobacter pylori in humans have not been fully elucidated. Research in the last decade has proposed that foodborne transmission, among others, may be a plausible route of human infection. Owing to the organism's fastidious growth characteristics and its ability to convert to viable, yet unculturable states upon exposure to stress conditions, the detection of H. pylori in foods via culture-dependent methods has been proven to be laborious, difficult and in most cases unsuccessful. Hence, nucleic acid-based methods have been proposed as alternative methods but, to date, only PCR-based methods have been reported in the literature. In the current study, fluorescence in situ hybridization (FISH) was used for the detection of H. pylori in raw, bulk-tank bovine milk. After repeated milk centrifugation and washing steps, the bacterial flora of raw milk was subjected to fixation and permeabilization and H. pylori detection was conducted by FISH after hybridization with an H. pylori-specific 16S rRNA-directed fluorescent oligonucleotide probe. Using this protocol, H. pylori was detected in four out of the twenty (20%) raw milk samples examined. The data presented in this manuscript indicate that FISH can serve as an alternative molecular method for screening raw bovine milk for the presence of H. pylori.

Transmission pathway of Helicobacter pylori: does food play a role in rural and urban areas?

Helicobacter pylori is a Gram-negative microaerophilic bacterium that has colonized the human gastric mucosa. This infection is very common and affects more than half of the human population. The prevalence is however unbalanced between rural developing areas (more than 80%) and urban developed areas (less than 40%). H. pylori is responsible for several pathologies, such as gastritis, peptic ulcer and gastric cancer but its transmission pathway is still not clear. The risk factors for H. pylori infection include poor social and economic development; poor hygienic practices; absence of hygienic drinking water; and unsanitary prepared food. There is evidence supporting a gastro-oral, oral-oral and faecal-oral transmission, but no predominant mechanism of transmission has been yet identified. Transmission may occur in a vertical mode (e.g. from parents to child) or in a horizontal mode (across individuals or from environmental contamination). In either case, the involvement of water and food cannot be excluded as vehicles or sources of infection. Indirect evidence of presence of H. pylori in water and food, namely the detection of its DNA and survival studies after artificial contamination of food and water has been described. This paper reviews data both favourable and against the role of water and food in the transmission of H. pylori, exploring their role as a potential transmission vehicle for person-to-person and food-chain transmission. The likelihood of the transmission pathway in developing rural and developed urban areas appears to be different. In developed areas, person-to-person transmission within families appears to be dominant, while in the rural developing areas the transmission pathway appears to be more complex. In this later case, the transmission by contaminated food, water, or via intensive contact between infants and non-parental caretakers may have a greater influence than within-family transmission.

High occurrence of Helicobacter pylori in raw goat, sheep and cow milk inferred by glmM gene: a risk of food-borne infection?

Helicobacter pylori is an organism widespread in humans and sometimes responsible for serious illnesses, such as gastric and duodenal ulcers, MALToma and even gastric cancer. It has been hypothesized that the infection route by H. pylori involves multiple pathways including food-borne transmission, as the microorganism has been detected from foods such as sheep and cow milk. This work reports the results of a survey conducted in order to investigate the presence of H. pylori in raw goat, sheep and cow milk produced in Southern Italy, employing a Nested Polymerase Chain Reaction (Nested-PCR) assay for the detection of the phosphoglucosamine mutase gene (glmM), as screening method followed by conventional bacteriological isolation. Out of the 400 raw milk samples examined, 139 (34.7%) resulted positive for the presence of glmM gene, but no strains were isolated. In this work H. pylori DNA has been firstly detected from 41 (25.6%) raw goat milk samples. The results deserve further investigations on the contamination source/s of the milk samples and on the major impact that it may have on consumers.

A new model for the transmission of Helicobacter pylori: role of environmental reservoirs as gene pools to increase strain diversity

Twenty-five years after the first successful cultivation and isolation of Helicobacter pylori, the scientific community is still struggling to understand the way(s) this bacterium is transmitted among the human population. Here, both epidemiologic and microbiologic evidence addressing this matter is reviewed and explored to conclude that most H. pylori successful colonizations are derived from direct person-to-person contact and that even though exposure of humans to H. pylori from environmental sources is a very common event, in most occasions the host is able to fight off infection. In addition, under a new model developed here, we propose that the near elimination of environmental reservoirs is the main responsible for the lower prevalence observed in the more industrialized countries by acting on two levels: by decreasing the number of direct infections and by diminishing the number of intraspecies recombination events for producing strain variation within H. pylori.

Congenital infections associated with international travel during pregnancy

With the overall increase in international travel, there is likely to be an increase in travel during pregnancy as well. In developing countries, pregnant women face exposures that can add significant risk for neonatal morbidity and mortality. Infections that can occur in utero or in the early neonatal period include malaria, yellow fever, tuberculosis, hepatitis, human immunodeficiency virus, leishmaniasis, toxoplasmosis, filariasis, Japanese encephalitis, rubella, typhoid fever, leptospirosis, dengue fever, Helicobacter pylori, and trypanosomiasis. When travel and potential exposure cannot be avoided, preventive measures are usually effective. Pretravel consultation should include careful discussion of length of travel, antimalarial prophylaxis, insect avoidance, food and water hygiene, vaccination, and body fluid precautions.

Fates of seeded Escherichia coli O157:H7 and Salmonella on selected fresh culinary herbs during refrigerated storage

The fates of seeded Escherichia coli O157:H7 and Salmonella on selected fresh culinary herbs were evaluated at a refrigerated temperature (4 degrees C). Fresh herbs, including cilantro, oregano, basil, chive, parsley, and rosemary, were inoculated with six-strain mixtures of E. coli O157:H7 and Salmonella, and the microbial populations were monitored at 1, 5, 11, 16, 19, and 24 days. For both pathogens, a significant decrease in the population (P < 0.0001) occurred within the first 5 days of storage (< 0.8 log). Both pathogens remained the highest on cilantro and the lowest on rosemary (P < 0.0001). Storage time had a significant effect on the survival of E. coli O157:H7; populations declined as storage time progressed. Although storage of cilantro, basil, and chive was terminated after 19 days because of deteriorated quality, significant numbers of both pathogens were recovered from the remaining fresh herbs after 24 days of storage. The results showed that both bacteria were extremely persistent on all test herbs under the test conditions. The results also reinforce the concept that, once contaminated, bacterial pathogens can persist on fresh herbs throughout a normal distribution time.

Pathogenesis of Helicobacter pylori Infection

SUMMARY

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori .

Pathogenesis of Helicobacter pylori Infection

SUMMARY

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori .

Pathogenesis of Helicobacter pylori Infection

SUMMARY

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori .

Pathogenesis of Helicobacter pylori infection

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.

Survival of Helicobacter pylori in artificially contaminated ultrahigh temperature and pasteurized milk

Helicobacter pylori (H. pylori) is a very important bacterial pathogen of humans which may cause gastrointestinal illnesses ranging from gastric and duodenal ulcers to neoplastic diseases such as MALToma and gastric cancer. Transmission via contaminated food is still uncertain but several authors believe this can realistically occur and milk may act as a vehicle of infection. This paper reports the results of H. pylori survival trials in pasteurized and ultrahigh temperature (UHT) milks artificially contaminated and aerobically stored at 4 degrees C. The results obtained showed that the four strains used in this study (H. pylori nat 18-19-20 and H. pylori ATCC 43504), had a progressive reduction in bacterial load with a median survival of 9 days in pasteurized milk and 12 days in UHT milk, with approximate average of initial inoculum of 10(5) and 10(6)cfu/ml, respectively. These findings are very important to clarify the route of transmission of H. pylori to humans via food and for implementation of a correct risk analysis for food safety purposes.

Multiplex-touchdown PCR assay for the detection and genotyping of Helicobacter pylori from artificially contaminated sheep milk

Helicobacter pylori (Hp) is an organism commonly present worldwide in the human population, sometimes causing serious illnesses such as duodenal and gastric ulcers, adenocarcinoma of the stomach, and low-grade B-cell mucosa-associated lymphoid tissue lymphoma of the stomach. This article describes a multiplex-touchdown PCR method for the identification and genotyping (vacA-s1/m1, sl/m2, and s2/m2-and cagA genes) of Hp directly from sheep milk artificially contaminated with Hp strains from human gastric biopsies and with Hp ATCC 43504. The strains from humans carried sl/m2 cagA+ and s2/m2 cagA allelic combinations, while the ATCC strains carried an sl/ml cagA+ allelic combination. The technique showed a sensitivity of 15 CFU/ml for species identification and of 1,500 CFU/ml for the detection of genes encoding for VacA and CagA. It has proven to be specific and rapid, and the authors suggest that it be used as a rapid screening method to ensure that sheep milk is uncontaminated with this organism.

Nutrient shock and incubation atmosphere influence recovery of culturable Helicobacter pylori from water

Three different media-Columbia agar, Wilkins-Chalgren agar, and Helicobacter pylori special peptone agar-were prepared in a diluted version and compared to the standard medium formulation in order to study a possible nutrient shock effect observed when recovering H. pylori from water by counting the number of CFU. This same parameter was subsequently used to evaluate the influence of the incubation atmosphere by using a modular atmosphere-controlled system to provide different atmospheres and by employing an established gas generation kit as a control. Both a low nutrient content of the media and a rapidly achieved microaerophilic incubation atmosphere proved to increase the numbers of environment-stressed H. pylori organisms recovered. An atmosphere of 5% CO(2), 5% O(2), and 3% H(2) is recommended, although other atmospheres with a low oxygen concentration are also acceptable. Besides highlighting and assessing the importance of several factors in the culturability of H. pylori, this paper demonstrates the potential ability to develop an optimized technique for recovery of this pathogen from water.

Development of a plating medium for selection of Helicobacter pylori from water samples

The goal of this study was to develop a simple plating medium to allow large-scale screening of water samples for the presence of Helicobacter pylori. Five conventional plating media (brain heart infusion, brucella agar, Columbia blood agar base, campylobacter agar kit Skirrow, and HPSPA medium), each containing a commercial antibiotic supplement, were initially evaluated. Eight strains selected as common waterborne organisms (Acinetobacter, Aeromonas, Bacillus, Escherichia coli, Enterobacter, Enterococcus, Helicobacter pylori, and Pseudomonas strains) were individually plated onto each of these media. Three organisms (Acinetobacter, E. coli, and H. pylori) were able to grow on all five media. This growth was unacceptable since Helicobacter grows very slowly and competing organisms must be inhibited for up to 7 days. Therefore, a more selective medium (HP agar) containing a novel mixture of growth supplements plus amphotericin B and polymyxin B was developed. This medium also included a phenol red color indicator for urease production. Aliquots of nonsterile well water that contained native flora (Flavobacterium, Serratia, Citrobacter, Pasteurella, Ochrobactrum, Rahnella, and unidentified molds) and were further adulterated with the eight strains listed above (10(6) CFU of each strain per 100 ml) were spiked with H. pylori and were plated. In spite of the heavy mixed microbial load, only H. pylori colonies grew during 7 days of incubation at 37 degrees C. The color indicator system allowed presumptive identification of H. pylori colonies sooner (12 to 20 h) than the conventional media tested allowed. The HP formulation developed in this study provides a medium with superior selectivity for H. pylori from mixed microbial populations in water and reduces the time required to complete the assay.

Detection of Helicobacter pylori in cow's milk

AIMS

To investigate the existence of Helicobacter pylori in cow's milk as one of the foods which most Japanese children eat.

METHODS AND RESULTS

Detection of H. pylori was demonstrated by the semi-nested polymerase chain reaction (PCR), a culture method and electron microscopy. Semi-nested PCR demonstrated the ureA gene of H. pylori in 13 of 18 (72.2%) raw milk samples and in 11 of 20 (55%) commercial pasteurized milk samples. Helicobacter pylori binding immunomagnetic beads with H. pylori-specific goat anti-H. pylori antibody was shown by electron microscopy in both raw and pasteurized milk positive for the ureA gene. Helicobacter pylori was cultured in one raw milk sample, whereas it was not cultured in pasteurized milk samples.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

There is a possibility that cow's milk is a transmission vehicle in childhood H. pylori infection, although we failed to confirm the survival of H. pylori in pasteurized milk.

Epidemiology and diagnosis of Helicobacter pylori infection

There have been no major breakthroughs in the field of epidemiology and diagnosis of Helicobacter pylori infection over the last year, thus for this reason, these two topics will be treated in the same chapter. Information on the incidence of infection, as in the study of Malaty et al. are now being published from long-term cohort follow-ups. The route of transmission of H. pylori remains controversial, with circumstantial evidence for infection via exposure to animals, contaminated water supplies and oral reservoirs being reported. The value of citric acid to improve urea breath test (UBT) results has been documented. A novel stool test has been released on the market and we are awaiting more information, while detection of antibodies in urine gave satisfactory results. However, the most interesting data comes from the study of McColl et al. who clearly proved on a large sample and a 1-year follow-up that the 'test and treat' strategy using UBT, as proposed in the Maastricht Consensus Report, is definitely the method to use.