鸡源肠炎沙门氏菌对抗菌药物的耐药性分析

目的 调查鸡源肠炎沙门氏菌临床分离株耐药特征。方法 从山东省不同来源分离肠炎沙门氏菌,采用微量肉汤稀释法对菌株进行19种抗菌药物敏感性分析;通过PCR方法对菌株携带的耐药基因进行检测;采用脉冲场凝胶电泳对不同场所分离的菌株进行PFGE分型。结果 肠炎沙门氏菌分离率为17.94%(178株),菌株对氨苄西林耐药率达到68.54%、对四环素耐药率达到66.85%、对磺胺甲恶唑和萘啶酸耐药率达到100%。而对庆大霉素、氯霉素、多粘菌素敏感,耐药率在5.62%以下。68.54%的菌株(122株)携带Ⅰ型整合子、bla_TEM和tetA基因。不同场所分离的肠炎沙门氏菌表现4种PFGE谱型。结论 山东省分离的肠炎沙门氏菌对青霉素类、四环素类药物耐药,携带Ⅰ型整合子、bla_TEM 和tetA耐药基因是导致菌株耐药的主要因素。     

Cardiovascular complications of Salmonella enteritidis infection

Salmonella has the ability to adhere to damaged endothelium, predisposing individuals to complications rarely seen with other Gram-negative organisms. Potential complications include endocarditis, infected atheroma or aneurysms, myocarditis and pericarditis. The present report describes two cases of Salmonella enteritidis-associated cardiovascular disease. Patient 1 is a young adult who presented with myopericarditis complicated by recurrent cardiac arrests following return from a tropical climate. This patient was successfully treated with a 14-day course of ciprofloxacin. Patient 2 is an elderly man who developed a pseudoaneurysm of the ascending aorta complicating S enteritidis bacteremia, and died of this complication. Recognition of potential complications of salmonellosis, especially in individuals with risk factors, is paramount in correctly diagnosing and managing these patients.     

Acalculous cholecystitis due to Salmonella enteritidis

Acute acalculous cholecystitis （AAC） is defined as an acute inflammation of the gallbladder in the absence of stones. We herein report a case of a young man who developed AAC after a Salmonella enteritidis gastrointestinal infection.     

Comparative analysis of intestinal microbial community diversity between healthy and orally infected ducklings with Salmonella enteritidis by ERIC-PCR

AIM： To analyze the difference of intestinal microbial community diversity between healthy and （S. enteritidis） orally infected ducklings.METHODS： Enterobacterial Repetitive Intergenic Consensus （ERIC）-PCR was applied to analyze the intestinal microbial community diversity and dynamic change including duodenum, jejunum, ileum, cecum and rectum from healthy ducklings and 7-day-old ducklings after oral infection with S. enteritidis at different time points.RESULTS： The intestinal microbial community of the control healthy ducklings was steady and the ERIC-PCR band numbers of the control healthy ducklings were the least with rectum and were the most with caecum. ERIC-PCR bands of orally inoculated ducklings did not obviously change until 24 h after inoculation （p.i.）. The numbers of the ERIC-PCR bands gradually decreased from 24 h to 72 h p.i., and then, with the development of disease, the band numbers gradually increased until 6 d p.i. The prominent bacteria changed because of S. enteritidis infection and the DNAstar of staple of ERIC-PCR showed that aerobe and facultative aerobe （Escherichia coli, Shigella, Salmonella） became preponderant bacilli in the intestine of orally infected ducklings with SE.CONCLUSION： This study has provided significant data to clarify the intestinal microbial community diversity and dynamic change of healthy and S. enteritidis orally infected ducklings, and valuable insight into the pathogenesis of S. enteritidis infection in both human and animals.     

2018-2021年南山区食物中毒中肠炎沙门氏菌与布利丹沙门氏菌遗传特征和耐药性分析北大核心CSCD

目的分析2018-2021年南山区食物中毒样品中分离的肠炎沙门氏菌(Salmonella Enteritidis S.Enteritidis)与布利丹沙门氏菌(Salmonella Blegdam.S.Blegdam),从遗传特征和耐药性角度了解细菌间的亲缘进化关系和耐药特征、为食源性疾病暴发溯源和临床诊治提供参考依据。方法分别对33株沙门氏菌采用脉冲场凝胶电泳(pulsed-field gel electrophoresis,PFGE)与全基因组序列方法(Whole genome sequencing,WGS)分析,同时测定30种药物的最小抑菌浓度(minimal inhibitory concentration,MIC)。结果33株菌分为8个PFGE型别,MLST型均为ST11型。全基因组k-mer系统发生树可见9簇。氨苄西林(AMP)、头孢唑啉(CFZ)、萘啶酸(NAL)、磺胺异噁唑(Sul)4种抗菌药物的检出率较高,均大于50%。20株菌对3类以上的药物耐药(60.60%),属于多重耐药,7株菌产ESBL酶。15株菌的耐药基因与耐药表型完全符合。结论2018-2021年,南山区由沙门氏菌引起的食物中毒事件中,沙门氏菌的总体遗传距离较近,但与数据库中其它肠炎沙门氏菌遗传距离较远,自成一簇。本研究中的沙门氏菌多重耐药现象严重,需加强对多重耐药株的监控及抗菌药物使用的监管。     

肠炎沙门菌rfbG基因缺失株的构建及其生物学特性研究

目的 探究rfbG基因对肠炎沙门菌毒力的影响,评价肠炎沙门菌缺失rfbG基因后作为减毒活疫苗的潜力。方法 利用自杀质粒介导的同源重组技术,无痕构建肠炎沙门菌Z11ΔrfbG缺失株,并对其生物学特性进行分析。结果 成功构建肠炎沙门菌Z11ΔrfbG缺失株,与野生株相比,缺失株Z11ΔrfbG生化特性没有发生变化,在LB液体培养基中生长速率较慢;缺失株生物被膜形成能力显著弱于野生株,其感染J774A.1细胞后,产生的细胞毒性亦显著低于野生株。此外,缺失株可与吖啶橙溶液发生凝集,但与O₉血清不发生凝集。结论 rfbG基因缺失显著降低了肠炎沙门菌Z11的毒力,且缺失株符合粗糙型菌株的特点,Z11ΔrfbG不仅具有作为沙门菌减毒活疫苗或载体的潜质,也具有作为DIVA疫苗的潜力,为肠炎沙门菌减毒活疫苗的开发研究奠定了基础。     

肠炎沙门菌YbjX基因缺失株的构建及生物学特性研究

为研究肠炎沙门菌外膜蛋白YbjX对该菌致病作用的影响,本研究利用 λ-Red同源重组系统构建了肠炎沙门菌(C50336)YbjX基因缺失突变株(C50336ΔYbjX),并对其生物学特性进行分析,探究YbjX蛋白在肠炎沙门菌致病过程中的作用。结果显示,缺失株C50336ΔYbjX与野生型菌株和回复菌株相比,其生长速度、生化特性无明显差异,但其在血清中和蛋清中的存活能力明显下降。此外,药敏试验结果表明YbjX基因缺失会引起沙门菌药物敏感性增强。进一步的,动物致病性实验表明,YbjX基因缺失会引起沙门菌毒力和巨噬细胞内存活能力的严重下降。本研究证实YbjX基因与肠炎沙门菌毒力密切相关,为进一步阐释肠炎沙门菌感染致病机制奠定基础。     

Gastrointestinal tract distribution of Salmonella enteritidis in orally infected mice with a species-specific fluorescent quantitative polymerase chain reaction

AIM: To identify and understand the regular distribution pattern and primary penetration site for Salmonella enteritidis (S. enteritidis) in the gastrointestinal tract. METHODS: Based on the species-specific DNA sequence of S. enteritidis from GenBank, a species-specific real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) was developed for the detection of S. enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the gastrointestinal tract, including duodenum, jejunum, ileum, cecum, colon, rectum, esophagus and stomach, from mice after oral infection. RESULTS: S. enteritidis was consistently detected in all segments of the gastrointestinal tract. The jejunum and ileum were positive at 8 h post inoculation, and the final organ to show a positive result was the stomach at 18 h post inoculation. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h post inoculation, with the jejunum, ileum and cecum containing high concentrations of S. enteritidis, whereas the duodenum, colon, rectum, stomach and esophagus had low concentrations. S. enteritidis began to decrease and vanished at 2 d post inoculation, but it was still present up to 5 d post inoculation in the jejunum, ileum and cecum, without causing apparent symptoms. By 5 d post inoculation, the cecum had significantly higher numbers of S. enteritidis than any of the other areas (P < 0.01), and this appeared to reflect its function as a repository for S. enteritidis. CONCLUSION: The results provided significant data for clarifying the pathogenic mechanism of S. enteritidis in the gastrointestinal tract, and showed that the jejunum, ileum and cecum are the primary sites of invasion in normal mice after oral infection. This study will help to further understanding of the mechanisms of action of S. enteritidis.     

Innate immune response to Salmonella typhimurium,a model enteric pathogen

The innate immune system provides the first line of defense against invading microorganisms by inducing a variety of inflammatory and antimicrobial responses. These responses are particularly important in the gastrointestinal tract, where the needs for efficient nutrient uptake and host defense collide. Many pathogens have evolved to specifically colonize the intestine, causing millions of cases of enteric infections a year. A paradigm of an enteric pathogen is Salmonella enterica, a gram-negative bacterium that causes a wide range of gastrointestinal and systemic diseases. Infections with Salmonella enterica serovar Typhimurium (S. typhimurium) lead to an acute intestinal inflammation in human and animal hosts, as a result of the bacterium invading the mucosa. A distinctive feature of Salmonella is that it has not only adapted to survive in a strong inflammatory environment, but it also uses this adaptation as a strategy to gain a growth advantage over the intestinal microbiota. We will use the model organism S. typhimurium to discuss the innate immune mechanisms employed by the mammalian gastrointestinal system and how the pathogen responds and subverts these mechanisms. In particular, we focus on the recognition of extra- and intra-cellular Salmonellae by germline-encoded pattern recognition receptors of the TLR and NLR families, and how Salmonella might profit from the activation of these receptors.     

Innate immune response to Salmonella typhimurium, a model enteric pathogen

The innate immune system provides the first line of defense against invading microorganisms by inducing a variety of inflammatory and antimicrobial responses. These responses are particularly important in the gastrointestinal tract, where the needs for efficient nutrient uptake and host defense collide. Many pathogens have evolved to specifically colonize the intestine, causing millions of cases of enteric infections a year. A paradigm of an enteric pathogen is Salmonella enterica, a gram-negative bacterium that causes a wide range of gastrointestinal and systemic diseases. Infections with Salmonella enterica serovar Typhimurium (S. typhimurium) lead to an acute intestinal inflammation in human and animal hosts, as a result of the bacterium invading the mucosa. A distinctive feature of Salmonella is that it has not only adapted to survive in a strong inflammatory environment, but it also uses this adaptation as a strategy to gain a growth advantage over the intestinal microbiota. We will use the model organism S. typhimurium to discuss the innate immune mechanisms employed by the mammalian gastrointestinal system and how the pathogen responds and subverts these mechanisms. In particular, we focus on the recognition of extra- and intra-cellular Salmonellae by germline-encoded pattern recognition receptors of the TLR and NLR families, and how Salmonella might profit from the activation of these receptors.     

脉冲场凝胶电泳在肠炎沙门菌食源性疾病溯源中的应用

目的对2006年广州地区食源性疾病中分离的肠炎沙门菌进行分子分型,探讨广州地区肠炎沙门菌的分子型别和多态性,为食源性疾病溯源及致病菌数据库的建立提供依据。方法采用限制性内切酶XbaI,对2006年分离到的菌株进行PFGE分子分型,使用BioNumericsVersion4.0软件(使用Dice系数和UPGMA法)对菌株进行聚类分析,并与深圳市的肠炎沙门菌PFGE型别进行比较。结果所有74株肠炎沙门菌均得到一致的PFGE克隆型,表明两次不同的食源性疾病均由同一PFGE型引起。广州与深圳的肠炎沙门菌PFGE图谱的比较表明,两地食源性疾病分离株具有很近的亲缘关系。结论PFGE分子分型与流行病学资料紧密结合可增强对肠炎沙门菌食源性疾病的溯源和预警。     

Alcohol Use and High-Risk Sexual Behavior Among Adolescents and Young Adults in Harare, Zimbabwe

We conducted a quantitative and qualitative study of alcohol use and high-risk sexual behavior among adolescents and young adults of age 15–21 years in Harare, Zimbabwe. Methods included a cross-sectional survey of youth sampled at nightclubs and bottle stores informed by participant observation, key informant interviews, and focus group discussions. Findings corroborated a cycle of HIV transmission that involves older men, younger women, and ultimately the steady partners of both. Nightclubs and other drinking establishments catering to youth can provide opportunities for preventing HIV transmission through stuctural interventions or targeted outreach education.     

‘Healers’ understandings of indigenous names for HIV/AIDS in Harare,Zimbabwe

Despite many years of HIV/AIDS education programming in Zimbabwe, there are still conflicting understandings of the disease, its genesis and its effects on the body. This is particularly true of traditional healers who, for better or worse, play a significant role in the education, care and treatment of people affected with the disease in Zimbabwe. Evidence from a sample of 50 urban-based healers illustrates the need for more thorough understandings of healers’ explanatory frameworks as well as more integrative approaches to developing health promotion and education interventions targeting healers. Based on qualitative data, this article explores local understandings of HIV/AIDS, particularly as embodied in indigenous names for the disease.     

Application of an indirect immunofluorescent staining method for detection of Salmonella enteritidis in paraffin slices and antigen location in infected duck tissues

AIM： To detect Salmonella enteritidis （S. enteritidis） in paraffin slices and antigen location in infected duck tissues.
METHODS： The rabbits were immunized with purified bacillus to obtain S. enteritidis-specific antibody, which were then extracted by the caprylic-ammonium sulphate method, purified through High-Q columns. An indirect immuno-fluorescent staining method （IFA） was established to detect the S. enteritidis antigen in paraffin slices. Detected S. enteritidis in each organ tissue of ducklings experimentally infected with S. enteritidis.
RESULTS： The gland of Garder, heart, kidney, spleen, liver, brain, ileum, jejunum, bursa of Fabricius from S. enteritidis experimentally infected ducklings were positive or strongly positive, and the S. enteritidis antigen mainly distributed in the infected cell cytoplasm.
CONCLUSION： IFA is an intuitionist, sensitive and specific method in detecting S. enteritidis antigen in paraffin wax slices, and it is a good method in diagnosis and antigen location of S. enteritidis. We also conclude that the gland of Garder, heart, kidney, spleen, liver, ileum, jejunum are target organs in S. enteritidis infections of duck, and S. enteritidis is an intracellular parasitic bacterium.     

Impact of a Single Session of Counseling on Partner Referral for Sexually Transmitted Disease Treatment, Harare, Zimbabwe

Counseling patients with sexually transmitted diseases (STD) to refer their partners to treatment is considered a means of preventing reinfection and controlling the spread of STD and is standard practice throughout the world. We conducted a randomized controlled trial to assess the impact of an enhanced counseling session on partner referral in Harare, Zimbabwe. The intervention consisted of an individualized confidential session with a trained counselor; standard care (control) relied on the treating clinician to discuss partner referral. A consecutive sample of 272 patients (135 men, 137 women) was randomly assigned to the intervention or control group; 137 (50%) completed follow- up. By intent-to-treat analysis, persons in the intervention arm were more likely to report notifying any partner compared to controls (92% vs. 67%, adjusted odds ratio 4.1, 95% confidence interval 1.3–13.2, p < .001). Across both study arms, women and married persons were more likely to notify partners, particularly spouses. Few persons notified casual partners. Qualitative data at follow-up identified diverse motivating factors and barriers to partner referral. A short, low-cost counseling session may increase the number of spouses referred to STD treatment in resource-poor, high-morbidity areas of sub-Saharan Africa. New methods of treating or notifying casual partners need to be evaluated.     

Quantitative studies of the regular distribution pattern for Salmonella enteritidis in the internal organs of mice after oral challenge by a specific real-time polymerase chain reaction

AIM： To identify and understand the regular distribution pattern for Salmonella enteritidis （S. enteritidis） in the internal organs of mice after an oral challenge over a 3 wk period.
METHODS： Assays based on the serovar-specific DNA sequence of S. enteritidis from GenBank, and a serovar-specific real-time, fluorescence-based quantitative polymerase chain reaction （FQ-PCR） were developed for the detection of S. enteritidis. We used this assay to detect genomic DNA of S. enteritidis in the blood and the internal organs, including heart, liver, spleen, kidney, pancreas, and gallbladder, from mice after oral challenge at different time points respectively.
RESULTS： The results showed that the spleen was positive at 12 h post inoculation （PI）, and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, the pancreas was positive at 20 h PI, and the final organs to show positive results were the kidney and gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24-36 h PI, with the liver and spleen containing high concentrations of S. enteritidis, whereas the blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 12 d PI in the gallbladder, 2 wk for the liver, and 3 wk for the spleen without causing apparent symptoms.
CONCLUSION： The results provided significant data for understanding the life cycle of S. enteritidis in the internal organs, and showed that the liver and spleen may be the primary sites for setting itself up as a commensa over a long time after oral challenge. Interestingly, it may be the first time reported that the gallbladder is a site of carriage for S. enteritidis over a 12 d period. This study will help to understand the mechanisms of action of S. enteriCdis infection in vivo.     

Salmonella enteritidis causing joint sepsis

Summary A 22-year-old male taking dexamethasone following resection of a medulloblastoma developed an acutely painful swollen knee from which salmonella enteritidis was cultured. He had no gastrointestinal symptoms; one stool culture was positive. Active metalloproteinases without inhibitors were detected in the synovial fluid, a characteristic finding in septic joints. S. enteritidis infecting joints is extremely rare despite being the second most frequent salmonella species after S. typhimurium causing infections in man. The recent findings of S. enteritidis in eggs, and poultry points to one more source of infection. Immunosuppression is likely to facilitate infection.     

The Association Between Alcohol Use, Sexual Risk Behavior, and HIV Infection Among Men Attending Beerhalls in Harare, Zimbabwe

HIV testing and a behavioral survey were conducted with a cross-sectional sample of 324 men recruited at beerhalls in Harare, Zimbabwe, to examine the relationship among alcohol use, high-risk sexual behavior, and HIV infection among male beerhall patrons and to evaluate the feasibility of using beerhalls as venues for male-centered HIV prevention activities. Recent HIV seroconversions were identified using the less-sensitive enzyme immunoassay. HIV education activities were provided inside beerhalls and qualitative methods were used to assess the acceptability of conducting HIV prevention activities and research at beerhalls. The prevalence of HIV infection was 30%; the prevalence of recent seroconversion was 3.4%. Having sex while intoxicated in the previous 6 months was reported by 31% of men and was strongly associated with recent HIV seroconversion as well as unprotected sex with casual partners and paying for sex. Acceptability of prevention and research activities was high among beerhall patrons, managers, and owners. Beerhalls present an environment associated with high-risk sexual behavior and concomitantly high rates of HIV seroconversion. Beerhalls are appropriate and feasible venues for delivering HIV prevention programs targeted at men in many regions of sub-Saharan Africa and the world.     

Pleural tuberculosis in Harare, Zimbabwe: the relationship between human immunodeficiency virus, CD4 lymphocyte count, granuloma formation and disseminated disease

objective   To elucidate the relationship between HIV, CD4¹ count and pleural TB. method   In a prospective study, 94 patients presenting at two large Harare hospitals with clinically suspected pleural TB were enrolled over a 10-month period. All underwent standardized evaluation, closed pleural aspiration and biopsy. Patients receiving directly observed anti-TB therapy were followed-up. results   Pleural TB was diagnosed in 90 individuals (median age 33 years; range 18-65; 64 males); the seroprevalence of HIV was 85%. HIV-positive patients were older than HIV-negative individuals (median age 33 vs 23 years, P = 0.013) and had a significantly lower median CD4¹ count (191 vs 1106 × 10⁶/l respectively, P = 0.004). A CD4¹ count of <200 × 10⁶/l was associated with a length of illness >30 days (65% vs 37%; P = 0.05), a positive pleural fluid smear (37% vs 0%; P = 0.0006) and a positive pleural biopsy Ziehl-Neelsen stain (35% vs 7%; P = 0.021). However, a relationship between CD4¹ count and either pleural granuloma formation or radiological evidence of disseminated disease was not observed. conclusion   In sub-Saharan Africa, TB pleural effusions have become associated with older age, a chronic onset, and an increased mycobacterial load. These data emphasize the complex relationship between pleural TB, HIV infection and a low CD4¹ count.     

Social and economic consequences of HIV and AIDS on children: case study of a high-density community in Harare,Zimbabwe

We present results from a household-based survey that was conducted in Mabvuku, a high-density community in Zimbabwe. The objective of the study was to improve understanding of social and economic consequences of HIV and AIDS on children. Children affected by HIV and AIDS (CABA) formed the treatment group while those not affected by HIV and AIDS (non-CABA) were the control group. We found that many of the differences in the socio-economic indicators that we studied between CABA and non-CABA were not significant. Therefore our results indicate a gloomy scenario for all the children. These results are consistent with existing literature which indicates that the impact of HIV and AIDS is exacerbated by poverty. Based on evidence from this paper, we conclude that programmes and interventions targeted at children should encompass both CABA and non-CABA within a framework of sustained commitment to improving the lives of these children. We hope that our findings will be used in the formulation of interventions and strategies to improve the situation of children affected by HIV and AIDS and/or living in impoverished communities.