The clinical relevance of microbiology specimens in head and neck space infections of odontogenic origin

It is common surgical practice to take a specimen for microbial culture and sensitivity when incising and draining infections of odontogenic origin in the head and neck. We aimed to find out if routine testing has any therapeutic value. We retrospectively studied 90 patients (57 male and 33 female) admitted to Northampton General Hospital for treatment of odontogenic infections, and reviewed admission details, antimicrobial treatment, microbiological findings and their sensitivity or resistance, and complications. Specimens were sent from 72 (80%) patients of which 61 (85%) were infected. The most commonly isolated organism was Streptococcus viridans. Interim reports were published after a mean of 3 days (range 1-4), and 94% of patients were discharged within a mean of 2 days (range 0-9) postoperatively. Almost 95% of patients were discharged before results were available, and there were no reported complications. We therefore suggest that microbial culture has little therapeutic value in the management of these patients. With culture and sensitivity tests costing £25 - £30, omission of this practice in the case of uncomplicated (single tissue space) odontogenic infections could save resources in the National Health Service without affecting the care of patients.     

Management of Odontogenic Space Infection with Microbiology Study

Introduction

Dental infection has plagued humankind for as long as our civilization has been a fight against microorganisms by man dates back to ancient civilization. The discoveries of antibiotics are encouraging trends towards conquest of the microbial infection.

Materials and Methods

This study emphasizes the detection of pathogenic microorganisms by microbiological examination and culture of specimens representative of the infection, importance of early and correct diagnosis of infections, prompt treatment and supportive care.

Results

The age group most commonly involved was in the third and fourth decades of life. Extraction followed by incision and drainage was done. The most commonly involved space was submandibular followed by buccal space. Thirty isolates were obtained. 43 % of the strains were strict anaerobes and 39 % were aerobes, with mixed growth was seen in 18.52 %. Amongst aerobes alpha hemolytic Streptococcus aureus and Peptostreptococcus as anaerobes were the most predominant followed by Bacteroides and Prevotella. Mixed aerobic and anaerobic isolates were obtained from 18.52 % of total cases. Overall resistance to Penicillin was 22 %, amongst aerobes.

Conclusion

Amoxicillin and Clavulanic acid combination performed better, as 100 % strains were sensitive to it. The results of this study saw a changing trend in terms of predominance of anaerobic bacteria over aerobic ones.     

Antimicrobial photodynamic effect of phenothiazinic photosensitizers in formulations with ethanol on Pseudomonas aeruginosa biofilms

Background dataMethylene blue (MB) and toluidine blue (TB) are recognized as safe photosensitizers (Ps) for use in humans. The clinical effectiveness of the antimicrobial photodynamic therapy with MB and TB needs to be optimized, and ethanol can increase their antimicrobial effect. Formulations of MB and TB containing ethanol were evaluated for their ability to produce singlet oxygen and their antibacterial effect on Pseudomonas aeruginosa biofilms.MethodsPhotoactivated formulations were prepared by diluting the Ps (250 μM) in buffered water (pH 5.6, sodium acetate/acetic acid), 10% ethanol (buffer: ethanol, 90:10), or 20% ethanol (buffer: ethanol, 80:20). Biofilms also were exposed to the buffer, 10% ethanol, or 20% ethanol without photoactivation. Untreated biofilm was considered the control group. The production of singlet oxygen in the formulations was measured based on the photo-oxidation of 1,3-diphenylisobenzofuran. The photo-oxidation and CFU (log₁₀) data were evaluated by two-way ANOVA and post-hoc Tukey’s tests.ResultsIn all the formulations, compared to TB, MB showed higher production of singlet oxygen. In the absence of photoactivation, neither the buffer nor the 10% ethanol solution showed any antimicrobial effect, while the 20% ethanol solution significantly reduced bacterial viability (P = 0.009). With photoactivation, only the formulations containing MB and both 10% and 20% ethanol solutions significantly reduced the viability of P. aeruginosa biofilms when compared with the control.ConclusionsMB formulations containing ethanol enhanced the antimicrobial effect of the photodynamic therapy against P. aeruginosa biofilms in vitro.     

置IUD子宫异常出血者子宫内膜细菌和病毒感染的研究

本文研究了育龄妇女子宫内膜细菌及病毒感染与宫内节育器（ＩＵＤ）所致子宫异常出血的关系。结果表明。置ＩＵＤ有异常出血组细菌总感染率为１０．５％（厌氧菌感染８．８％，需氧菌感染１．７％），显著高于未置ＩＵＤ正常组，是置ＩＵＤ未出血组的３．６２倍。置ＩＵＤ有异常出血组病毒总感染率为２９．５％。（巨细胞病毒（ＣＭＶ）感染１２．５％，单纯疱疹病毒Ⅱ（ＨＳＶⅡ）感染１７％，显著高于置ＩＵＤ无异常出血组和未置ＩＵＤ正常组。置ＩＵＤ＜１２月有异常出血者的细菌感染率显著高于置ＩＵＤ＞１２月者；而病毒感染则反之。宫颈糜烂的程度与置ＩＵＤ子宫有异常出血者宫内感染有关。     

论《内经》的发病观与医学微生物学、免疫学的关系

<黄帝内经>是中医药学的经典之作,它以辩证唯物主义为基础,体现了先进的、科学的世界观和方法论,为中医学的发展奠定了理论依据和指导思想.中西医结合,不能仅停留于实验室水平,应当从理论上加以融合,相互促进,共同提高.我们试从发病的角度探讨<内经>与医学微生物学和免疫学之间的相互关系,旨在为中西医理论层面上相结合起抛砖引玉之用.     

怀化地区泌尿生殖道感染者支原体感染情况及耐药性分析

目的了解泌尿生殖道感染患者解脲支原体(Uu)和人型支原体(Mh)感染及耐药情况。方法采用深圳银科支原体检测试剂盒,培养Uu和Mh,并作药物敏感试验。结果支原体的总检出率为41.98%,其女性支原体检出率(50.34%)显著高于男性(31.09%)(P<0.01),单纯Uu阳性率(30.15%)明显高于Uu Mh混合(11.32%)和单纯Mh阳性率(0.51%)(P<0.01)。支原体对环丙沙星、氧氟沙星、司帕沙星、罗红霉素、螺旋霉素和左旋氧氟沙星耐药率均>60.00%,而强力霉素、美满霉素和交沙霉素对支原体抗菌活性好,敏感率均>80.00%。结论本地区支原体感染率高,分离出支原体具有多重耐药性和高耐药性,临床治疗需根据药敏结果选择合适的抗菌药物。     

Murine retrovirus Pr65gag forms a 130K dimer in the absence of disulfide reducing agents

Gazdar-murine sarcoma virus (Gz-MSV) particles, obtained from tissue culture fluids of chronically infected HTG-2 hamster cells are immature in morphology and contain uncleaved Pr65gag as the predominant protein (greater than 95% Coomassie blue stain) (A. Pinter and E. deHarven, 1979, Virology 99, 103-110; Y. Yoshinaka and R. B. Luftig, 1982, Virology 118, 380-388). When Gz-MSV particles are disrupted in 1% sodium dodecyl sulfate (SDS) and then analyzed by SDS-polyacrylamide gel electrophoresis (PAGE) in the absence of reducing agents, such as beta-mercaptoethanol (beta-MSH) almost half of the Pr65gag Coomassie blue-stained band is detected as a band at a Mr of 130K. Electrophoretic blotting studies with monospecific antisera against MuLV p30, p15, p12, and p10 showed that the 130K band cross-reacted with all four antigens suggesting that it was a dimer of Pr65gag. Two-dimensional (2D) SDS-PAGE where the first dimension was run under nonreducing conditions and the second with beta-MSH, supported the contention that the 130K band was a dimeric complex of Pr65gag. One also saw minor amounts of a 260K and higher polymeric forms of Pr65gag on the SDS gels, suggesting that polymeric forms may exist as well. When 32P-labeled Gz-MSV particles obtained by in vivo labeling of infected HTG-2 cells with [32P]PPi were electrophoresed on SDS-PAGE, only 10% of the 32P label was detected at the 130K position. In contrast, 30% of the Coomassie blue-stained Pr65gag material was found at 130K on the 2D gels. This suggests that unphosphorylated Pr65gag is more likely to participate in dimer formation than phosphorylated Pr65gag. Pr65gag of Moloney murine leukemia virus (M-MuLV), which is present as a minor (5% of stain) protein band on SDS-PAGE also showed 130K dimers. Further, in beta-MSH-deficient SDS preparations of Gz-MSV, electrophoresed after trypsin treatment, a 32K band that stained with p15, but not p10, p12, nor p30, antisera was observed. If beta-MSH was added, this band was no longer present. Thus Pr65gag dimerization in immature MuLV particles appears to at least involve the p15 region of the polyprotein. Since p15 is an extremely hydrophobic protein, formation of Pr65gag dimers may occur when virion precursor proteins are brought to the cell membrane during virus assembly.     

The molecular basis of HCV-mediated immune dysregulation

Chronic hepatitis C virus (HCV) infection, which occurs in over 85% of patients and causes mild to severe liver disease, is a growing burden to health systems worldwide. The propensity of HCV to establish persistent infection suggests that the virus, which is non-cytopathic, has evolved one or more mechanisms aimed at evading host immunity. In addition to the appearance of quasispecies, which may arise under selective pressure during B and T cell responses, HCV gene products interact with host proteins in order to subvert immune surveillance. Gaining insight into these interactions may provide the basis for novel therapies aimed at preventing chronic HCV infection.     

Trichomonas vaginalis infection activates cells through toll-like receptor 4

While Trichomonas vaginalis infection can cause inflammation and influx of leukocytes into the female genital tract, the molecular pathways important in inducing these effects are not known. This study determined if infection with T. vaginalis activates cells through toll-like receptor 4 (TLR4). Genital tract secretions from infected women stimulated TNF-alpha production by cells with functional TLR4 (350 pg/ml) but significantly less by cells that are unresponsive to TLR4 ligands (44 pg/ml, P = 0.001). Secretions collected after clearance of infection also induced significantly lower responses by cells with functional TLR4 (136 pg/ml, P = 0.008). TNF-alpha responses were not reduced by Polymyxin B and did not correlate with beta(2)-defensin levels, indicating that stimulation of cells was not through lipopolysaccharide or beta(2)-defensin. These studies show that T. vaginalis infection results in the appearance in the genital tract of substance(s) that stimulate cells through TLR4, suggesting a mechanism for the inflammation caused by this infection.