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.     

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。     

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.     

Enhanced expression of vascular endothelial growth factor by periodontal pathogens in gingival fibroblasts

Vascular endothelial growth factor (VEGF) has recently attracted attention as a potent inducer of vascular permeability and angiogenesis. Aberrant angiogenesis is often associated with lesion formation in chronic periodontitis. The aim of the present study was to investigate the properties of VEGF expression in human gingival fibroblasts (HGF) culture. HGF were stimulated with lipopolysaccharide (LPS), vesicle (Ve) and outer membrane protein (OMP) from Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. HGF constitutively produced VEGF and levels were significantly enhanced (P < 0.01) by stimulation with Ve and OMP from A. actinomycetemcomitans and P. gingivalis at concentrations of 10 microg/ml or higher. On the other hand, VEGF levels were not increased by LPS stimulation. VEGF mRNA expression was also observed in Ve- and OMP-stimulated HGF. A vascular permeability enhancement (VPE) assay was performed using guinea pigs to ascertain whether supernatant from cultures of Ve- and OMP-stimulated HGF enhance vascular permeability in vivo. Supernatant from cultures of Ve- and OMP-stimulated HGF strongly induced VPE. This was markedly suppressed upon simultaneous injection of anti-VEGF polyclonal antibodies with the supernatant. Heating and protease treatment of the stimulants reduced the VEGF enhancing levels in Ve and OMP in vitro. These results suggest that Ve and OMP may be crucial heat-labile and protease-sensitive components of periodontal pathogens that enhance VEGF expression. In addition, VEGF might be associated with the etiology of periodontitis in its early stages according to neovascularization stimulated by periodontal pathogens causing swelling and edema.     

Influence of Moxifloxacin,Comparator Drugs and Some Fractions of Pulmonary Surfactant on Adherence of Some Respiratory Pathogens

Background: This study evaluated the effect of moxifloxacin and comparator drugs with or without some fractions of pulmonary surfactant, as surfactant protein-A (SP-A) and phospholipids, on the adherence of the most common respiratory pathogens. Materials and Methods: The adherence of respiratory pathogens to a bronchial epithelial cell line was tested. Antimicrobials were used at 1/2, 1/4 and 1/8 minimum inhibitory concentration (MIC), SP-A at 1 and 5 μg/ml and phospholipids at 50 μg/ml. Results: At 1/2 MIC moxifloxacin, ciprofloxacin, amoxicillin-clavunalate and ceftriaxone reduced the adherence of Staphylococcus aureus and Streptococcus pneumoniae to values of 40-50%. At the same concentration, cotrimoxazole reduced the adherence values of Moraxella catarrhalis and Haemophilus influenzae to about 50%, while β-lactams showed high efficacy only on H. influenzae, with adherence values of about 40%. The addition of SP-A and/or phospholipids to the tested antibiotics had no effect on bacterial adherence. Conclusion: The non-interference of SP-A and/or phospholipids with the suppressive effect that some antibiotics exert on bacterial adherence could represent a favorable event during antibiotic therapy. Received: March 23, 2001·Revision accepted: May 10, 2002     

泌尿系感染病原菌对氟喹诺酮类抗菌药物耐药性研究

目的了解我院越尿系感染患者病原菌分布及对4种氟喹诺酮类抗菌药物耐药情况。方法收集2003年1月～2005年10月自我院分离的780株细菌。采用纸片扩散法进行4种氟喹诺酮类抗菌药物药敏试验。结果从尿液标本分离的780株病原菌中，大肠埃希菌、肠球菌、表皮葡萄球菌、铜绿假单胞菌、肺炎克雷伯菌分列前五位（47．2％、17．6％、9．9％、6．7％和5．4％）。大肠埃希菌产ESBLs株检出率为45．7％，肺炎克雷伯菌产ESBLs株检出率为28．6％．耐甲氧西林表皮葡萄球菌（MRSE）和高水平庆大霉素耐药肠球菌（HLGR）检出率分别为74．0％和81．0H．它们对4种氟喹诺酮类抗菌药物的耐药率高于非MRSE、非HLGR和非产ESBLs菌株，呈现多重耐药的趋势。结论大肠埃希菌仍然是泌尿系感染的主要致病菌，尿路感染应根据抗生素敏感试验选择敏感药物进行舍理用药，并应检测MRSE，HLGR和产ESBLs菌株的多重耐药情况。     

Increase of faecal bifidobacteria due to dietary oligosaccharides induces a reduction of clinically relevant pathogen germs in the faeces of formula-fed preterm infants

In a previous study on formula-fed preterm infants, we were able to demonstrate that dietary oligosaccharides (a mixture of 90% galacto-oligosaccharides and 10% fructo-oligosaccharides in a concentration of 1 g/dl) stimulate the growth of faecal bifidobacteria. In the present explorative analysis of this study, we focus on the effect of the dominance of bifidobacteria on the presence of clinically relevant pathogens ( Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus, Pseudomonas aeruginosa, Enterobacter, Klebsiella, Proteus, Streptococcus group B, Clostridium difficile, Bacillus subtilis and Acinetobacter ).
Conclusion : The data demonstrate that stimulation of bifidobacteria by prebiotic oligosaccharides reduces the presence of clinically relevant pathogens in the faecal flora, indicating that prebiotic substances might have the capacity to protect against enteral infections.     

论湿热分消法

对湿热分消法作了较系统的诠释，包括除热中之湿、清湿中之热、消湿热兼夹、上中下内外分消湿热4个方面，对临床治疗湿热之邪具有一定的指导意义。