Putative periodontal pathogens in the subgingival plaque of Sudanese subjects with aggressive periodontitis

Background and objectivesThere has been limited study of the bacterial species associated with aggressive periodontitis (AgP) in high-risk populations in Africa. The aim of this study was to investigate and quantify the presence of four putative periodontal pathogens in the subgingival plaque of Sudanese subjects with AgP. A secondary aim was to investigate the effect of varying the detection threshold on the reported prevalence of the bacterial species investigated.Materials and methodsSubgingival plaque samples were collected from AgP cases (n = 73) and healthy controls (n = 71). Bacterial DNA was extracted and analyzed by quantitative polymerase chain reaction for the detection and quantification of four putative periodontal pathogens: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola and Tannerella forsythia.ResultsAt the lowest detection threshold (>10¹ cells), P. gingivalis (p < 0.0001) was more prevalent in AgP cases than controls. T. forsythia and T. denticola had a high prevalence (>70%) in AgP cases at all detection levels. While T. forsythia was significantly more frequently identified in AgP than in controls at all detection thresholds, this was only the case for T. denticola at the intermediate threshold (>10² cells). A. actinomycetemcomitans was identified less frequently than the other bacterial species with no difference in its prevalence between AgP cases and controls.ConclusionThe prevalence of the putative periodontal pathogens investigated varied considerably in Sudanese subjects with AgP and in periodontally healthy controls depending on the detection thresholds applied. T. forsythia was identified as having the strongest association with AgP.     

Clinical relevance of the ESKAPE pathogens

In recent years, the Infectious Diseases Society of America has highlighted a faction of antibiotic-resistant bacteria (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) – acronymically dubbed ‘the ESKAPE pathogens’ – capable of ‘escaping’ the biocidal action of antibiotics and mutually representing new paradigms in pathogenesis, transmission and resistance. This review aims to consolidate clinically relevant background information on the ESKAPE pathogens and provide a contemporary summary of bacterial resistance, alongside pertinent microbiological considerations necessary to face the mounting threat of antimicrobial resistance.     

Antibacterial synergy between quercetin and polyphenolic acids against bacterial pathogens of fish

ObjectiveTo evaluate combinations of quercetin with gallic acid, p-anisic acid and cinnamic acid in vitro for synergistic activity against common Gram-negative bacterial pathogens of fish viz., Aeromonas hydrophila, Aeromonas salmonicida and Edwardsiella tarda.MethodsAntibacterial activity of quercetin, gallic acid, p-anisic acid and cinnamic acid was determined against selected bacterial pathogens individually, followed by combination of quercetin with polyphenolic acids using serial microplate dilution method measuring minimum inhibitory concentrations. Fractional inhibitory concentration indices were calculated.ResultsQuercetin and other polyphenolic compounds exhibited antibacterial action against the selected fish pathogens with mean minimum inhibitory concentrations ranging from 0.83 to 2.5 mg/mL. It was observed that fractional inhibitory concentration indices for combination of quercetin with gallic acid, p-anisic acid or cinnamic acid against Aeromonas salmonicida were less than 0.5, indicating synergistic interaction. However, the above combinations produced additive antimicrobial activity against Aeromonas hydrophila and Edwardsiella tarda.ConclusionsPositive antibacterial interaction was evident between quercetin and selected polyphenolic acids in vitro.     

Effects of climate change on the persistence and dispersal of foodborne bacterial pathogens in the outdoor environment: A review

Abstract

According to the Intergovernmental Panel on Climate Change (IPCC), warming of the climate system is unequivocal. Over the coming century, warming trends such as increased duration and frequency of heat waves and hot extremes are expected in some areas, as well as increased intensity of some storm systems. Climate-induced trends will impact the persistence and dispersal of foodborne pathogens in myriad ways, especially for environmentally ubiquitous and/or zoonotic microorganisms. Animal hosts of foodborne pathogens are also expected to be impacted by climate change through the introduction of increased physiological stress and, in some cases, altered geographic ranges and seasonality. This review article examines the effects of climatic factors, such as temperature, rainfall, drought and wind, on the environmental dispersal and persistence of bacterial foodborne pathogens, namely, Bacillus cereus, Brucella, Campylobacter, Clostridium, Escherichia coli, Listeria monocytogenes, Salmonella, Staphylococcus aureus, Vibrio and Yersinia enterocolitica. These relationships are then used to predict how future climatic changes will impact the activity of these microorganisms in the outdoor environment and associated food safety issues. The development of predictive models that quantify these complex relationships will also be discussed, as well as the potential impacts of climate change on transmission of foodborne disease from animal hosts.     

339例新生儿败血症分析

目的分析新生儿败血症的临床特点及院内感染的相关因素。方法回顾分析医院近6年中339例新生儿败血症的临床资料、院内感染相关因素、感染菌株及细菌对抗菌药的敏感度。结果新生儿败血症细菌侵入途径与呼吸道、消化道、皮肤和脐部感染有关,使用多种抗生素、早产儿、低出生体重、呼吸机的使用、严重基础疾病（如先天性心脏病）是导致院内感染的危险因素,感染菌株以凝固酶阴性葡萄球菌居多。几种革兰氏阴性杆菌对亚胺培南敏感率最高,革兰氏阳性球菌感染主要为凝固酶阴性葡萄球菌,其苯唑西林耐药株的检出率高于80%,未发现对万古霉素的耐药株。结论在医院感染中条件致病菌引起的感染较多,医护人员在进行医疗操作时要加强无菌观念,减少不必要的污染。     

某院常见病原菌的耐药性分析及抗菌药物选择

目的 解某院临床分离常见病原菌的耐药状况。以指导临床合理选用抗菌药物。方法 2005年1月～2006年12月某院临床分离菌株用Kirby-Bauer法进行药敏试验。结果 3425株细菌中，革兰阳性球菌占36．9％，革兰阴性杆菌占63．1％。耐甲氧西林金黄色葡萄球菌（MRSA）和甲氧西林敏感金黄色葡萄球菌（MSSA）位居革兰阳性菌前2位，在2006年分别占52．8％和24．O％。金黄色葡萄球菌对利福平、多西环素、替考拉宁和万古霉素的耐药率较低，为O～38．6％。在革兰阴性杆菌中分离率居前5位的依次为铜绿假单胞菌、大肠埃希菌、阴沟肠杆菌、鲍曼不动杆菌和克雷伯菌，这些细菌对美罗培南的耐药率最低，在0～10．6％之间，其次为哌拉西林-他唑巴坦、头孢吡肟和亚胺培南。结论 临床分离菌株的耐药性呈逐年增高的趋势，临床医生要根据病原学检测及药敏试验结果合理选择抗菌药物。     

牙周致病菌和致龋菌对羟基磷灰石的附着能力

目的研究牙周致病菌和致龋菌对羟基磷灰石(HA)的附着能力。方法将与牙周病和龋病发生密切相关的6种国际参考标准菌株(牙龈卟啉单胞菌、伴放线放线杆菌、具核梭杆菌、变形链球菌、血链球菌、黏性放线菌),分别接种于模拟口腔环境的改良MD-300恒化器中培养,1 h后分离培养HA表面附着的细菌,检测各菌种对HA的附着能力及其相互作用。结果检测菌种中,血链球菌对HA的附着能力最强,其他依次为黏性放线菌、变形链球菌、伴放线放线杆菌、具核梭杆菌和牙龈卟啉单胞菌。血链球菌和黏性放线菌均能增强牙周致病菌对HA的附着能力,变形链球菌降低牙龈卟啉单胞菌的附着能力;所有牙周致病菌均降低血链球菌对HA的附着能力,而对变形链球菌和黏性放线菌无明显影响。结论牙周致病菌对HA的附着能力明显弱于致龋菌,其借助早期定植菌成为牙周生态系的优势菌和牙周病的主要病原菌。     

Prevalence of enteric pathogens among community based asymptomatic individuals

BACKGROUND AND AIMS: The objective of this study was to describe the prevalence of pathogenic microorganisms in asymptomatic individuals in a community study in Melbourne, Australia. METHODS: The study population was a subset of 2803 individuals participating in the Water Quality Study; a community based randomized trial. Faecal specimens (1091) were collected over a 3-month period from asymptomatic individuals. Specimens were tested for a range of bacteria including Salmonella, Shigella and Campylobacter species. Rotavirus and adenovirus were detected using a Rota-Adeno latex kit, and protozoa were detected using a permanent stain (modified iron-haemotoxylin). RESULTS: Twenty-eight known pathogens were identified from the 1091 faecal specimens, a total carriage rate of 2.6%. Giardia species were present in 18 specimens (1.6%), Salmonella in four (0.4%), Campylobacter in one (0.1%), Cryptosporidium in four (0.4%) and adenovirus in one (0.1%). Blastocystis hominis was found in 65 specimens. The median age of those without a pathogen was 12.5 years compared with 6.6 years for those with a pathogen (P=0.02). CONCLUSIONS: Except for Giardia, pathogens were rarely found in asymptomatic individuals in the community. The prevalence of pathogens was higher in children than adults.     

厄他培南——治疗多重耐药菌感染的新选择

厄他培南（商品名INVANZ^TM）为美国默克制药公司新近开发的新型广谱碳青霉烯类抗生素，它具有强效的抗菌活性，抗菌谱广。已证实厄他培南对革兰氏阳性（G^＋）、革兰氏阴性（G^-）和厌氧菌都具有活；对治疗腹腔感染、复杂性尿路感染、复杂性皮肤及附属器感染及多重耐药菌引起的感染疗效较高；适用于入院时已有感染（不包括疑诊病原体为铜绿假单胞菌感染）的治疗等。