Herellea (Acinetobacter) and Pseudomonas ovalis (P. putida) from Frozen Foods

Seventeen strains of Herellea vaginicola (Acinetobacter antitratus) and 8 of Pseudomonas ovalis (P. putida), isolated from 23 (6.3%) of 364 samples of frozen, foil-pack foods, were identified and characterized morphologically and biochemically. Herellea was isolated from 17 foods (4.7%), P. ovalis from 6 (1.6%). No Mima were found. The food samples included precooked frozen meats, precooked and uncooked frozen vegetables, and uncooked frozen desserts. The bacteria were detected in the food with a procedure used generally for the detection of salmonellae. The pseudomonad simulated the characteristics of Herellea on Sellers differential agar, except for the fact that it fluoresced. From consideration of the habitat and pathogenicity of Herellea and Mima, it is concluded that, although the presence of these bacteria may not be desirable, their significance in food remains unanswered.     

The VP6 protein of rotavirus interacts with a large fraction of human naive B cells via surface immunoglobulins

Immunity to human group A rotavirus (RV), a major cause of viral gastroenteritis in infants, involves B lymphocytes that provide RV-specific antibodies. Additionally, some arguments suggest that naive B cells could be implicated in the first steps of the immune response against RV. The aim of our study was to analyze the interaction of VP6 and VP7 RV capsid proteins with human B cells depending on the immune status of the individual, i.e., naive or RV experienced. For this purpose, a two-color virus-like particle flow cytometry assay was devised to evaluate the blood B-lymphocyte reactivity to VP6 and VP7 proteins from healthy RV-exposed adults, recently infected infants, and neonates at birth. Both VP6 and VP7 interactions with B cells were mediated by surface immunoglobulins and probably by their Fab portions. VP7-reactive B lymphocytes were mainly detected from RV-experienced patients and almost exclusively in the CD27-positive memory cell fraction. Conversely, VP6-reactive B lymphocytes were detected at similar and high frequencies in adult, infant, and neonate samples. In adult samples, VP6 reacted with about 2% of the CD27-negative (CD27(neg)) naive B cells. These results demonstrated that the VP6 RV protein interacted with a large fraction of naive B lymphocytes from both adults and neonates. We propose that naive B cell-VP6 interaction might influence the strength and quality of the acquired immune response and should be considered for elaborating RV vaccine strategies.     

Proportion of sporadic gastroenteritis cases caused by rotavirus, norovirus, adenovirus and bacteria in Japan from January 2000 to December 2003

Many kinds of virus and bacterium have been identified as pathogens that cause sporadic gastroenteritis (SG). Among the pathogens, rotavirus (RV), norovirus (NV; previously known as Norwalk-like virus), and adenovirus (AdV) types 40/41 have been considered as the prevalent viruses implicated in the aetiology of childhood gastroenteritis. In the present study, we attempted to estimate monthly proportions of SG cases caused by the viral agents (RV, NV, AdV and other viruses (OV)) and bacterial agents in the whole of Japan. The estimation was carried out by using time series data of the incidence of SG and the viral and bacterial agents of SG, which were collected by a nationwide surveillance system in Japan from January 2000 to December 2003. It was confirmed that, in the dominant period of RV and NV, the proportion of RV-associated SG and that of NV-associated SG indicate almost same level with each other: 46-69% during February-May for RV, and 41-75% during October-December for NV.     

Trivalent Combination Vaccine Induces Broad Heterologous Immune Responses to Norovirus and Rotavirus in Mice

Rotavirus (RV) and norovirus (NoV) are the two major causes of viral gastroenteritis (GE) in children worldwide. We have developed an injectable vaccine design to prevent infection or GE induced with these enteric viruses. The trivalent combination vaccine consists of NoV capsid (VP1) derived virus-like particles (VLPs) of GI-3 and GII-4 representing the two major NoV genogroups and tubular RV recombinant VP6 (rVP6), the most conserved and abundant RV protein. Each component was produced in insect cells by a recombinant baculovirus expression system and combined in vitro. The vaccine components were administered intramuscularly to BALB/c mice either separately or in the trivalent combination. High levels of NoV and RV type specific serum IgGs with high avidity (>50%) as well as intestinal IgGs were detected in the immunized mice. Cross-reactive IgG antibodies were also elicited against heterologous NoV VLPs not used for immunization (GII-4 NO, GII-12 and GI-1 VLPs) and to different RVs from cell cultures. NoV-specific serum antibodies blocked binding of homologous and heterologous VLPs to the putative receptors, histo-blood group antigens, suggesting broad NoV neutralizing activity of the sera. Mucosal antibodies of mice immunized with the trivalent combination vaccine inhibited RV infection in vitro. In addition, cross-reactive T cell immune responses to NoV and RV-specific antigens were detected. All the responses were sustained for up to six months. No mutual inhibition of the components in the trivalent vaccine combination was observed. In conclusion, the NoV GI and GII VLPs combination induced broader cross-reactive and potentially neutralizing immune responses than either of the VLPs alone. Therefore, trivalent vaccine might induce protective immune responses to the vast majority of circulating NoV and RV genotypes.     

Evidence of the co‐circulation of enteric viruses in sewage and in the population of Greater Cairo

Aims: To characterize major enteric viruses (enterovirus, rotavirus, norovirus, astrovirus and adenovirus) in the sewage of Greater Cairo and to compare the results with clinical data collected during the same period. Methods and Results: Seventy‐two sewage samples from two waste water treatment plants were collected from April 2006 through February 2007. Enteroviruses, noroviruses (NoVs) and rotaviruses (RVs) were detected by RT‐PCR in 22%, 18% and 8·3% of the samples, respectively. No adenovirus and astrovirus was detected. G2P[8], G9P[8], G1P[8], G2P[4] and rare G12 RV isolates were detected in the environment as well as a bovine RV. The environmental NoV strains mostly belonged to genogroup I (84%). Rotaviruses and some of the NoVs were similar to those found in the clinical samples at the same time. Conclusions: The comparison of environmental and clinical data suggests that similar RV and NoV isolates were circulating in the environment and in the population during the same period. Significance and Impact of the Study: Few studies have investigated the prevalence and the epidemiology of RVs and NoVs in Cairo. This work is the first to establish a correlation between viral gastroenteritis and the concomitant presence of enteric viruses in the environment for Greater Cairo where combined environmental and clinical surveys should help to prevent infections caused by these major pathogens.     

Staphylococcal Growth and Enterotoxin Production in Meat

Preliminary attempts were made to explain the association of staphylococcal food poisoning with cooked rather than uncooked meats. The abilities of various meats to support the growth of an enterotoxigenic staphylococcus, and the production of enterotoxin A, were determined. The production of enterotoxin was detected by means of serological procedures. Little or no growth was obtained when the inoculum was mixed with raw ground beef. When the surfaces of raw and cooked meats were inoculated, however, good growth was obtained with the production of enterotoxin.     

Presence of polycyclic aromatic hydrocarbons in some South Indian food components.

South Indian food dishes, comprising several deep fried items have been proved to be mutagenic. Polycyclic aromatic hydrocarbons (PAHs) such as, benzo(a)pyrene, chrysene and dibenzanthracene, which are potent and proven carcinogens have been identified and quantified in several of the commonly consumed South Indian food dishes and food components. Most of the pyrolysed items contained PAHs in appreciable quantities. PAHs were detected in significant levels in salted, sundried and oil fried vegetables and fishes. Some of the raw and uncooked food components also revealed the presence of PAHs.     

The neutrophil chemiluminescence response to Pneumocystis carinii is stimulated by GM-CSF and gamma interferon

An enzyme-linked immunosorbent assay (ELISA) with antibodies specific to beta, epsilon and iota ib toxins of Clostridium perfringens was developed to detect beta, epsilon and iota ib toxins, respectively. The ELISA was sensitive enough to detect as little as 1.0 ng/ml of purified beta and iota ib toxins and 0.1 ng/ml of purified epsilon toxin. By means of the ELISA method, 192 isolates of C. perfringens from food samples in Japan and Thailand, and 58 isolates from patients suffering from gas gangrene or gastroenteritis were examined. One isolate from food samples in Japan, three from food samples in Thailand and five from stools of patients with gastroenteritis were C. perfringens type D. One type B and one type C were detected from the stools of patients with gastroenteritis.     

Rotavirus stimulates release of serotonin (5-HT) from human enterochromaffin cells and activates brain structures involved in nausea and vomiting

Rotavirus (RV) is the major cause of severe gastroenteritis in young children. A virus-encoded enterotoxin, NSP4 is proposed to play a major role in causing RV diarrhoea but how RV can induce emesis, a hallmark of the illness, remains unresolved. In this study we have addressed the hypothesis that RV-induced secretion of serotonin (5-hydroxytryptamine, 5-HT) by enterochromaffin (EC) cells plays a key role in the emetic reflex during RV infection resulting in activation of vagal afferent nerves connected to nucleus of the solitary tract (NTS) and area postrema in the brain stem, structures associated with nausea and vomiting. Our experiments revealed that RV can infect and replicate in human EC tumor cells ex vivo and in vitro and are localized to both EC cells and infected enterocytes in the close vicinity of EC cells in the jejunum of infected mice. Purified NSP4, but not purified virus particles, evoked release of 5-HT within 60 minutes and increased the intracellular Ca²⁺ concentration in a human midgut carcinoid EC cell line (GOT1) and ex vivo in human primary carcinoid EC cells concomitant with the release of 5-HT. Furthermore, NSP4 stimulated a modest production of inositol 1,4,5-triphosphate (IP₃), but not of cAMP. RV infection in mice induced Fos expression in the NTS, as seen in animals which vomit after administration of chemotherapeutic drugs. The demonstration that RV can stimulate EC cells leads us to propose that RV disease includes participation of 5-HT, EC cells, the enteric nervous system and activation of vagal afferent nerves to brain structures associated with nausea and vomiting. This hypothesis is supported by treating vomiting in children with acute gastroenteritis with 5-HT₃ receptor antagonists.     

Predominance of Norovirus and Sapovirus in Nicaragua after Implementation of Universal Rotavirus Vaccination

Background

Despite significant reduction of rotavirus (RV) infections following implementation of RotaTeq vaccination in Nicaragua, a large burden of patients with diarrhea persists.

Methods

We conducted a community- and hospital-based study of the burden of RV, norovirus (NV) and sapovirus (SV) infections as cause of sporadic acute gastroenteritis (GE) among 330 children ≤ 5 years of age between September 2009 and October 2010 in two major cities of Nicaragua with a RotaTeq coverage rate of 95%.

Results

We found that NV, SV and RV infections altogether accounted for 45% of cases of GE. Notably, NV was found in 24% (79/330) of the children, followed by SV (17%, 57/330) and RV (8%, 25/330). The detection rate in the hospital setting was 27%, 15% and 14% for NV, SV and RV respectively, whereas in the community setting the detection rate of RV was < 1%. Among each of the investigated viruses one particular genogroup or genotype was dominant; GII.4 (82%) for NV, GI (46%) for SV and G1P[8] (64%) in RV. These variants were also found in higher proportions in the hospital setting compared to the community setting. The GII.4.2006 Minerva strain circulating globally since 2006 was the most common among genotyped NV in this study, with the GII.4-2010 New Orleans emerging in 2010.

Conclusions

This study shows that NV has become the leading viral cause of gastroenteritis at hospital and community settings in Nicaragua after implementation of RV vaccination.     

长春地区轮状病毒流行株VP7基因的遗传变异

A组轮状病毒是引起婴幼儿秋冬季病毒性腹泻的主要病原.目前没有有效的治疗药物,应用安全而有效的疫苗是控制重症腹泻的首要措施.对当地A组轮状病毒流行株的主要中和抗原VP7的编码基因进行遗传变异分析,可以为疫苗的应用和开发提供有益的指导.利用ELISA方法对长春地区1999～2005年的腹泻患儿标本检测A组轮状病毒,RT-PCR方法对阳性标本进行G血清分型,发现长春地区2001年以后流行的轮状病毒以G3型血清为主.选取1999～2005年的G3型轮状病毒标本31份,对其VP7基因进行扩增、克隆、测序,经过计算机分析比对,31株G3型轮状病毒VP7基因核苷酸序列没有显著差异.同一流行季节的毒株具有较相似的遗传变异特征.在2003年轮状病毒流行季节内,有6株G3型分离株的VP7基因在碱基1 038位置上出现一个碱基缺失.毒株发生在A、B、C三个高变区的碱基突变,位点相同或者位置临近.2002年以后毒株的基因突变增加,非高变区的碱基变异增加,这可能有助于维持G3型轮状病毒成为流行株.有规律的变异多发生在高变区,但是非高变区的非连续性变异的增加值得引起注意.     

Binding Patterns of Rotavirus Genotypes P[4], P[6], and P[8] in China with Histo-Blood Group Antigens

Rotaviruses (RVs) are an important cause of severe gastroenteritis in children. It has been found that RV may recognize the histo-blood group antigens (HBGAs) as ligands or receptors and bind HBGAs in a type-dependent manner. In this study, we investigated the binding specificity of VP8* proteins from human rotaviruses (RV) that are prevalent in China including genotypes P[4], P[6], and P[8]. Through the saliva- and oligosaccharide-based binding assays, we found that the VP8* proteins of P[4] and P[8] RV showed similar reactivity with the Le^b and H type 1 antigens, while P[6] RV weakly bound the Le^b antigen. These findings may facilitate further research into RV host specificity and vaccine development.     

<Emphasis Type="BoldItalic">In vitro</Emphasis> availability of some essential minerals in commonly eaten processed and unprocessed Caribbean tuber crops

The levels of three essential minerals Ca, Fe and Mg and the extent of their availability were assessed in four commonly eaten Caribbean tuber crops [dasheen (Xanthosoma spp.), Irish potato (Solanum tuberosum), sweet potato (Ipomoea batatas) and yellow yam (Dioscorea cayenensis)] in their processed and unprocessed states. Calcium was highest in cooked dasheen (5150±50 mg/kg) while Magnesium was highest in uncooked Irish potato (3600±200 mg/kg). There was no significant loss of calcium from the food samples upon cooking. All the uncooked food samples displayed higher levels minerals assessed compared to the cooked samples except for cooked Irish potato that recorded the level of iron (182.25±8.75 mg/kg). Availability of these minerals in the cooked and uncooked tubers crops upon digestion also showed a similar pattern. In conclusion, the consumption of these tuber crops in the Caribbean may not be responsible for the reported cases of iron deficiency in the region. However, the␣availability of minerals from these tuber crops when consumed with other foods (the usual practice in the Caribbean) needs further investigation.     

High-Pressure Inactivation of Rotaviruses: Role of Treatment Temperature and Strain Diversity in Virus Inactivation

Rotavirus (RV) is the major etiological agent of acute gastroenteritis in infants worldwide. Although high-pressure processing (HPP) is a popular method to inactivate enteric pathogens in food, the sensitivity of different virus strains within same species and serotype to HPP is variable. This study aimed to compare the barosensitivities of seven RV strains derived from four serotypes (serotype G1, strains Wa, Ku, and K8; serotype G2, strain S2; serotype G3, strains SA-11 and YO; and serotype G4, strain ST3) following high-pressure treatment. RV strains showed various responses to HPP based on the initial temperature and had different inactivation profiles. Ku, K8, S2, SA-11, YO, and ST3 showed enhanced inactivation at 4°C compared to 20°C. In contrast, strain Wa was not significantly impacted by the initial treatment temperature. Within serotype G1, strain Wa was significantly (P < 0.05) more resistant to HPP than strains Ku and K8. Overall, the resistance of the human RV strains to HPP at 4°C can be ranked as Wa > Ku = K8 > S2 > YO > ST3, and in terms of serotype the ranking is G1 > G2 > G3 > G4. In addition, pressure treatment of 400 MPa for 2 min was sufficient to eliminate the Wa strain, the most pressure-resistant RV, from oyster tissues. HPP disrupted virion structure but did not degrade viral protein or RNA, providing insight into the mechanism of viral inactivation by HPP. In conclusion, HPP is capable of inactivating RV at commercially acceptable pressures, and the efficacy of inactivation is strain dependent.     

组织血型抗原:轮状病毒可能的潜在受体

轮状病毒(RVs)是引起婴幼儿及动物非细菌性胃肠炎的重要病原体.研究发现,人类组织血型抗原(HBGAs)可能是RVs的结合受体.HBGAs具有丰富的多态性,包含ABO、分泌型及Lewis抗原.研究表明,不同P型的RVs与HBGAs的结合具有型特异性,而且不同人群对各型RVs易感性存在差异.因此,研究RVs与HBGAs的相互作用对于阐明RV感染的致病机理及RV疫苗的设计具有重要意义.     

Immunomagnetic separation and conventional culture procedure for detection of naturally occurring Salmonella in raw pork sausages and chicken meat

The aim of the study was to compare immunomagnetic separation (IMS) and conventional selective enrichment procedures using selenite cystine broth (SC) and Rappaport–Vassiliadis broth (RV) in 137 naturally contaminated food samples (69 raw pork sausages and 68 chicken meat). The utilization of SC or IMS appeared to be the most appropriate enrichment procedure: 15 out of 18 Salmonella -positive samples (83·3%) were detected by SC and 12 (66·7%) by IMS; RV yielded only seven positive isolations (38·9%). However, RV yielded the highest count of Salmonella colonies per plate and the lowest interference by competing organisms. IMS could become a reliable alternative to standard enrichment procedures and a combined IMS and selective enrichment broth could increase the chance of Salmonella recovery.     

Traditional Living Habits of the Taz Tundra Population: A Paleoparasitological Study

An excavation of the Vesakoyakha II–IV and Nyamboyto I burial grounds was conducted during the 2014 field season, and soil samples from intact burials dating from the 19th and 20th centuries, respectively, were analyzed to determine interactions between parasites and host/vectors. Considering the discovery of Diphyllobothrium sp. and Taenia sp. eggs in soil samples from the pelvic region, diphyllobothriasis was the most frequent helminthic infection among the Taz Nenets. The Nyamboyto Nenets mainly consumed uncooked fish, while the Vesakoyakha Nenets had a bigger variety in food choices, including reindeer meat. Nenets children were given raw fish from early childhood. The paleoparasitological results corroborate rare ethnographic records about the consumption of uncooked reindeer cerebrum which led to beef tapeworm helminthiases. This is the first parasitological report of helminthic diseases among the Taz Nenets, and, as such, it provides insight into their subsistence activities and food patterns and broadens our understanding of their health condition.