Isolation, characterization and antibiotic resistance of Proteus mirabilis from Belgian broiler carcasses at retail and human stool.

Proteus mirabilis is an important pathogen involved in human urinary tract infections, and also more isolated from stools of patients with diarrheal disease than from healthy patients. The role of food, especially poultry products as source for human infection and multi-resistant strains remains unclear. As a resident in broilers' intestines, P. mirabilis can contaminate broiler carcasses due to slaughter practices, and be a risk for human infection. The present study evaluated the performance of five isolation media, and subsequently examined the presence of P. mirabilis on broiler carcasses at retail. Additionally, isolates were characterized by the Dienes' test, repetitive element PCR fingerprinting and pulsed-field gel electrophoresis, and their antibiotic resistance profile determined. Using a combined isolation protocol on blood agar, xylose lysine deoxycholate agar and violet red bile glucose agar, P. mirabilis was isolated from 29 out of 80 broiler carcasses (36.25%) with a mean contamination level of 2.25 ± 0.50 log10 CFU/g. A high strain heterogeneity was present in isolates from broilers and human stool. The same strains were not shared, but the antibiotic resistance profiling was similar. A role of poultry products as source for human infection should be taken into account.

Assessment of food microbiological indicators applied on poultry carcasses by culture combined MALDI-TOF MS identification and 16S rRNA amplicon sequencing.

Examination of the bacterial contamination on food products is still largely performed by standardized culture methods, though culture-independent methods are suggested as a more reliable approach. Knowledge of the diversity of bacteria isolated from food as well as the impact of the plate incubation conditions applied are still understudied. The impact of incubation at 7 °C and 30 °C on total aerobic bacterial count and diversity, and the performance of ISO methods generally applied in microbiological quality examination were assessed by culture combined MALDI-TOF MS identification and 16S rRNA amplicon sequencing. Examining breast skin of 16 chicken carcasses, no significant impact of the incubation temperature on the total aerobic bacteria level and diversity was detected, limiting the usefulness of additional psychrophilic examination. Bacteria phenotypically similar to Pseudomonas, were identified on selective CFC plates, and on MRS agar plates for lactic acid bacteria, Escherichia coli and Staphylococcus were commonly present. Application of 16S rRNA amplicon sequencing revealed a higher bacterial diversity, but the impact of the DNA extraction kit applied, and the detection of non-viable bacteria should be taken into account to interpret the final outcome.

Prevalence of intestinal parasites in companion dogs with diarrhea in Beijing, China, and genetic characteristics of Giardia and Cryptosporidium species.

Companion animals including dogs are one of the important components in One Health. Parasites may cause not only diseases in pet animals but also many zoonotic diseases infecting humans. In this study, we performed a survey of intestinal parasites in fecal specimens (n = 485) collected from outpatient pet dogs with diarrhea in Beijing, China, for the entire year of 2015 by microscopic examination (all parasites) and SSU rRNA-based nested PCR detection (Giardia and Cryptosporidium). We observed a total of 124 (25.6%) parasite-positive specimens that contained one or more parasites, including Giardia duodenalis (12.8%), Cryptosporidium spp. (4.9%), Cystoisospora spp. (4.3%), trichomonads (4.3%), Toxocara canis (3.5%), Trichuris vulpis (0.6%), and Dipylidium caninum (0.2%). Among the 55 dog breeds, infection rates were significantly higher in border collies and bulldogs, but lower in poodles (p < 0.05). Risk factor analysis suggested that age was negatively correlated with the infection rate (p < 0.00001), while vaccination and deworming in the past 12 months could significantly reduce the parasite infections (p < 0.01). Among the 62 Giardia-positive specimens, 21 were successfully assigned into assemblages using glutamate dehydrogenase (gdh) and/or beta-giardin (bg) genes, including assemblage D (n = 15), C (n = 5), and F (n = 1). Among the 24 Cryptosporidium-positive specimens by SSU rRNA PCR, 20 PCR amplicons could be sequenced and identified as Cryptosporidium canis (n = 20). Collectively, this study indicates that parasites are a significant group of pathogens in companion dogs in Beijing, and companion dogs may potentially transmit certain zoonotic parasites to humans, particularly those with weak or weakened immunity.

Greater alteration of gut microbiota occurs in childhood obesity than in adulthood obesity.

The children's gut microbiota, associated with the development of obesity, is in maturation. The impact of obesity on the gut microbiota in childhood could have a more significant effect than on adulthood and eventually be lifelong lasting, but it has been rarely studied. Aimed to discover the difference in gut microbiota between children and adults with obesity, we collected published amplicon sequencing data from National Center for Biotechnology Information (NCBI) and re-analyzed them using a uniform bioinformatic pipeline, as well as predicted the obesity using gut microbiota based on the random forest model. Summarizing common points among these cohorts, we found that the gut microbiota had a significant difference between children with and without obesity, but this difference was not observed in adult cohorts. Based on the random forest model, it was more challenging to predict childhood obesity using gut microbiota than adulthood obesity. Our results suggest that gut microbiota in childhood is more easily affected than in adulthood. Early intervention for childhood obesity is essential to improve children's health and lifelong gut microbiota-related health.

Small intestinal microbiota composition altered in obesity-T2DM mice with high salt fed.

Obesity has become a global concern because of increasing the risk of many diseases. Alterations in human gut microbiota have been proven to be associated with obesity, yet the mechanism of how the microbiota are altered by high salt diet (HSD) remains obscure. In this study, the changes of Small Intestinal Microbiota (SIM) in obesity-T2DM mice were investigated. High-throughput sequencing was applied for the jejunum microbiota analysis. Results revealed that high salt intake (HS) could suppress the body weight (B.W.) in some extent. In addition, significant T2DM pathological features were revealed in high salt-high food diet (HS-HFD) group, despite of relatively lower food intake. High-throughput sequencing analysis indicated that the F/B ratio in HS intake groups increased significantly (P < 0.001), whereas beneficial bacteria, such as lactic acid or short chain fatty acid producing bacteria, were significantly decreased in HS-HFD group (P < 0.01 or P < 0.05). Furthermore, Halorubrum luteum were observed in small intestine for the first time. Above results preliminary suggested that in obesity-T2DM mice, high dietary salt could aggravate the imbalance of composition of SIM to unhealthy direction.

Perturbation on gut microbiota impedes the onset of obesity in high fat diet-induced mice.

High-calorie intake has become one of the most common causes of dietary obesity, which eventually develops into type 2 diabetes mellitus (T2DM). Microbiota, along with the length of the gastrointestinal tract, is related to metabolic disorders, but its shifts and following impact on metabolic disorders due to external perturbation are still unclear. To evaluate shifts of microbiota from the proximal to the distal intestine and their impact on metabolic disorders, we profiled jejunal and colonic microbiota with the perturbation using high salt (HS) and antibiotic-induced microbiota depletion (AIMD) in diet-induced obesity (DIO) mice and analyzed the association with parameters of both obesity and blood glucose. After ten weeks of feeding DIO mice with HS intake and AIMD, they failed to develop obesity. The DIO mice with HS intake had T2DM symptoms, whereas the AIMD DIO mice showed no significant difference in blood glucose parameters. We observed that the jejunal and colonic microbiota had shifted due to settled perturbation, and jejunal microbiota within a group were more dispersed than colonic microbiota. After further analyzing jejunal microbiota using quantified amplicon sequencing, we found that the absolute abundance of Colidextribacter (R = 0.695, p = 0.001) and Faecalibaculum (R = 0.631, p = 0.005) in the jejunum was positively correlated with the changes in BW and FBG levels. The predicted pathway of glucose and metabolism of other substances significantly changed between groups (p <0.05). We demonstrated that the onset of obesity and T2DM in DIO mice is impeded when the gut microbiota is perturbed; thus, this pathogenesis depends on the gut microbiota.

Bacterial shifts on broiler carcasses at retail upon frozen storage.

Freezing broiler carcasses, industrially or at home, not only delays spoilage, but also is expected to increase food safety by hampering growth of food pathogens. However, detailed knowledge on microbial changes after a short or longer freezing period of fresh broiler meat in home freezing setting is lacking and no comparison between different freezing periods has been published yet. The present study combined classical isolation techniques and identification by MALDI-TOF MS with 16S rRNA amplicon sequencing to assess bacterial contamination on broiler carcasses that were either bought fresh and then frozen for short periods (total n = 20) in home freezing, or industrial frozen one (total n = 4) at retail. Changes in total aerobic bacteria (TAB) were also studied on 78 freshly bought broiler carcasses that were then stored frozen for up to 6 months in domestic freezers. Salmonella and Campylobacter were examined to assess the effect of freezing on controlling common foodborne pathogens. The contamination level of mesophilic and psychrotrophic TAB was numerically equal on carcasses at retail, either fresh or frozen at different time points. After short and long freezing period, a decrease in counts of mesophilic TAB was observed, while changes in counts of psychrotrophic TAB were rarely observed. No correlation between home freezing period and TAB load, either mesophilic (R = -0.006, p = 0.949) or psychrotrophic (R = 0.080, p = 0.389), was observed. No Salmonella and Campylobacter was detected on industrial frozen carcasses but on fresh carcasses at retail, either pre-freezing or after freezing. The bacterial communities were influenced by freezing, in which some genera showed significantly changes in relative abundance after freezing. In conclusion, from a food safety point of view, freezing of meat products does not serve as safety hurdle, and freezing should only be considered as a method for extending shelf life compared with fresh chicken meat. Applying hygienic slaughter procedures to keep the initial contamination as low as possible, and the maintenance of the cold chain during further processing are the key factors in food safety.

Evaluation of microbial contamination of different pork carcass areas through culture-dependent and independent methods in small-scale slaughterhouses.

Routine evaluation of the slaughter process is performed by the enumeration of the aerobic colony count, Enterobacteriaceae and Salmonella spp. on the carcass through destructive or non-destructive methods. With non-destructive methods, bacteria are counted from a minimum area of 100 cm2 in different sampling sites on the pork carcasses, and the results of these investigated areas are pooled to one value for the complete carcass evaluation (a total of 400 cm2). However, the composition of the bacterial community present on the different sampling areas remains unknown. The aim of the study was to characterize the microbial population present on four areas (ham, back, jowl and belly) of eight pork carcasses belonging to two different slaughterhouses through culture-dependent (Matrix-assisted laser desorption/ionization time-of-flight Mass Spectrometry MALDI-TOF MS, combined with 16S rRNA gene sequencing) and complementary culture-independent (16S rRNA amplicon sequencing) methods. The presence of Salmonella spp. and Y. enterocolitica was additionally assessed. Using MALDI-TOF MS, Staphylococcus, Pseudomonas, and Escherichia coli were found to dominate the bacterial cultures isolated from the 8 carcasses. Based on the 16S rRNA amplicon sequencing analyses however, no specific genus clearly dominated the bacterial community composition. By using this culture-independent method, the most abundant genera in microbial populations of the ham, back, jowl and belly were found to be similar, but important differences between the two slaughterhouses were observed. Thus, present data suggests that the indigenous bacterial population of individual animals is overruled by the microbial population of the slaughterhouse in which the carcass is handled. Also, our data suggests that sampling of only one carcass area by official authorities may be appropriate for the evaluation of the hygienic status of the carcasses and therefore of the slaughter process.

Analyses of the Bacterial Contamination on Belgian Broiler Carcasses at Retail Level.

Broilers are not equally exposed to bacterial contamination during rearing and processing, resulting in areas with different bacterial communities on carcasses at retail. The determination of these communities is also affected by the examination methods applied. The present study aimed to assess the bacterial communities on neck, breast, and back skin on broiler carcasses at retail through classical International Organization of Standardization based isolation methods combined with identification by matrix-assisted laser desorption ionization time-of-flight mass spectrum (MALDI-TOF MS) and 16S amplicon sequencing. Twelve commercially and eight organically reared broilers slaughtered in four slaughterhouses were examined. Significantly higher anaerobic bacterial counts were observed on the neck skin than on the breast and back skin. By the combination of cultivation and amplicon sequencing, remarkable shifts in bacterial communities were determined on the breast and back skin, but not on the neck skin. Although the aerobic bacteria contamination levels were not different between the areas, different bacterial communities were observed. The impact of the slaughterhouse to the overall microbial composition was rather small. Organically reared broilers had unique bacterial communities. In conclusion, compared to the breast skin, the neck, and back skin had a larger potential for bacterial spoilage, in particular when anaerobic storage conditions are applied. The distribution of bacteria on the different areas could be related to the contamination during slaughter as well as the bird-rearing methods.

[Rolling friction: a desing of artificial knee joint].

Resorption and osteolysis of periimplant bones resulting from the wear debris of artificial joint will cause long-term loosening. A new type of rolling knee artificial joint without UHMWPE based on the mechanics of rolling friction is designed for alleviating this problem. Because of low friction force, the resistance of extension and flexion is reduced strikingly and the stress on the interface between prosthesis and bone is reduced evidently. In addition, the bio-toxicity caused by the wear debris of UHMWPE will not occur absolutely. In consequence, the rolling artificial joint can prevent the trend of long-term loosening of the prosthesis efficiently.

Application of the cross-bridge microvascular anastomosis when no recipient vessels are available for anastomosis: 85 cases.

The purpose of this article is to introduce the results of free tissue transfers using the technique of the cross-bridge microvascular anastomosis when the recipient lacks suitable vessels for anastomosis. Between May of 1982 and June of 2002, a series of 85 patients underwent this procedure. The transferred tissues were the free latissimus dorsi myocutaneous flap, the free vascularized fibula, the free fibular osteocutaneous flap, and the free iliac osteocutaneous flap, alone or in combination. The donor vessels were the anterior tibial artery and great saphenous vein, the posterior tibial artery and its venae comitantes, and the radial artery and cephalic vein. Good results were achieved. The success rate reached 95.29 percent. The authors believe this procedure can be performed in the event of serious tissue defect where the vessels are unsuitable for anastomosis.