Modifying action of oxytocin on the biological properties of the causative agents of anaerobic non-clostridial infection

In a number of in vitro experiments the effect of oxytocin on the antilysozyme and anticomplemental activity of Propiobacterium propionicum, Bacteroides fragilis, Prevotella melaninogenica and Peptostreprtococcus anaerobius, isolated from patients with acute pyoinflammatory pleuropulmonary diseases, was studied. Antibiotic resistance dynamics of the infective agents under study to lincomycin, clindamycin, thienam, vancomycin was also detected. The inhibiting activity of oxytocin on the persistence properties of B. fragilis, P. melanogenica and P. anaerobius was noted. Under the influence of the preparations used changes in the sensitivity of the strains to a number of antibiotics of the lincosamide, carbapenem and glycopeptide groups were found to occur. The data thus obtained were indicative of the possible mechanisms of action of oxytocin in the treatment of acute pyoinflammatory pleuropulmonary diseases of anaerobic nonclostridial etiology.     

Antibacterial chemotherapy in anaerobic osteomyelitis caused by gunshot wounds

Thirty three patients with a 7-year history of chronic gunshot osteomyelitis were examined. Non-sporogenic anaerobes were isolated from 28 patients. Gram-positive cocci and gram-negative rods predominated in the anaerobic microflora. Radical surgical interventions combined with adequate antibacterial chemotherapy yielded satisfactory results. The postoperative cavities were drained to provide aerobic conditions in all the parts. Antibacterial drugs and in particular dioxidine solutions and KF were used locally. When antibioticograms were available 7 to 10 days after, the antibiotics in combination with enzymes such as terrylitin and lidase were used with constant irrigation of wounds with furacillin or boric acid solutions. In the empirical therapy, the following scheme was most frequently used: 600 mg of lincomycin, thrice, intramuscularly; 80 mg of gentamicin, thrice, intramuscularly and as an obligatory agent 500 mg of trichopol, thrice, orally. After availability of the antibioticograms the use of the antibiotics was adjusted and continued up to 10 to 12 days. In severe cases 0.1% solution of dioxidine was used intravenously drop-wise in a dose of 300 mg 2 times a day as well as tiberal or clindamycin, intravenously, drop-wise. The antibacterial drugs were added to the drainage until the latter was removed. Relapses of the disease over 4 years were observed only in 3 out of 26 operated patients.     

Microbiological diagnosis of suppurative-inflammatory processes of the E. N. T. organs and the maxillo-mandibulo-facial region under suspicion of anaerobic non-clostridial infection

The etiological role of non-sporulating anaerobic bacteria as causative agents of suppurative-inflammatory diseases (SID) of the maxillo-mandibulo-facial region and the E. N. T. organs as studied. Express diagnosis of anaerobic infection was carried out by means of gas-liquid chromatography. The species-specific composition of the microflora of the suppurative focus was investigated. It was established that only obligate anaerobes in monoculture or in association were isolated from patients with so-called "sterile" inoculations when strictly anaerobic bacteriological technique was used. The use of anaerobic bacteriological technique of investigation enlarged the spectrum of the microflora isolated from the suppurative focus from 5 to 26 species. Results of chromatographic and bacteriological examinations were compared; the main causes of obtaining false-positive and false-negative results of chromatography were analysed. Statistical processing using factor analysis has shown that the information power of chromatographic examination of the metabolites of anaerobic bacteria is higher in comparison with the main clinical-laboratory indices, but statistical processing using cluster analysis and correlation analysis has revealed that an index like metabolic activity reflects the degree of real participation of anaerobic microflora in the development of the pathological process, and can be used in the clinic for the evaluation of the degree of severity of the course of the SID and of the effectiveness of treatment.     

Complex and unexpected outcomes of antibiotic therapy against a polymicrobial infection

Antibiotics are our primary approach to treating complex infections, yet we have a poor understanding of how these drugs affect microbial communities. To better understand antimicrobial effects on host-associated microbial communities we treated cultured sputum microbiomes from people with cystic fibrosis (pwCF, n = 24) with 11 different antibiotics, supported by theoretical and mathematical modeling-based predictions in a mucus-plugged bronchiole microcosm. Treatment outcomes we identified in vitro that were predicted in silico were: 1) community death, 2) community resistance, 3) pathogen killing, and 4) fermenter killing. However, two outcomes that were not predicted when antibiotics were applied were 5) community profile shifts with little change in total bacterial load (TBL), and 6) increases in TBL. The latter outcome was observed in 17.8% of samples with a TBL increase of greater than 20% and 6.8% of samples with an increase greater than 40%, demonstrating significant increases in community carrying capacity in the presence of an antibiotic. An iteration of the mathematical model showed that TBL increase was due to antibiotic-mediated release of pH-dependent inhibition of pathogens by anaerobe fermentation. These dynamics were verified in vitro when killing of fermenters resulted in a higher community carrying capacity compared to a no antibiotic control. Metagenomic sequencing of sputum samples during antibiotic therapy revealed similar dynamics in clinical samples. This study shows that the complex microbial ecology dictates the outcomes of antibiotic therapy against a polymicrobial infection.Subject terms: Microbiome, Microbial ecology     

Aryloxoalcanoic compounds induce resistance to antibiotic therapy in urinary tract infection caused by Escherichia coli

Clofibric acid (CL) is a compound used to control hypertriglyceridemia, and ethacrynic acid (ET) is administered to enhance diuresis. These compounds are structurally analogous to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as they have a chlorinated phenoxy moiety. As these agents are mainly excreted by the renal route, they could potentially coexist with Escherichia coli in the urinary tract of infected patients. Induction of the in vitro resistance of E. coli to hydrophilic antibiotics was determined by increasing the values of the minimum inhibitory concentration (2-40-fold). These results correlated with drastically inhibited expression of the hydrophilic bacterial channel OmpF. In vivo assays were performed in ascending urinary tract infection in female BALB/c mice. Treatment with the hydrophilic antibiotic cephalexin 25 mg kg(-1) day(-1) by the oral route diminished renal infection. The CFU mean values in the kidneys were between 75% and 89% lower than those in animals without treatment. Simultaneous exposure to CL (at a therapeutic dose, 28.6 mg kg(-1) day(-1)) did not change the effect of the treatment. In contrast, ET at 2.9 mg kg(-1) day(-1) or 2,4-D at 70 mg kg(-1) day(-1) inhibited the antibiotic therapeutic effect. Moreover, 2,4-D dramatically increased bacterial infection after 9 days of exposure.     

Clinical and economic expedience of ertapenem therapy of complicated urinary tract infection

Clinical and economic investigation of various antibiotics use in the treatment of complicated urinary tract infection (CUTI) was performed under the Russian economic environment. The drugs of comparison were ertapenem, ceftriaxone and levofloxacin. Direct costs and their structure were shown, and the cost efficiency was calculated. Alternative analysis and one-side susceptibility analysis were performed. In complicated urinary tract infections when the major pathogens were Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis it was clinically and economically reasonable to start the treatment with ceftriaxone or ertapenem, while levofloxacin could be an alternative strategy. When the effects of the acquired resistance on the treatment effectiveness were evaluated (SIS model) it was shown that the pathogens susceptibility to ertapenem was preserved for a significantly longer time than that to ceftriaxone or levofloxacin (60 months). Such a parameter may serve as an additional evidence of the reasonable use of ertapenem as the starting treatment of CUTI.     

Pyocyaneus infection of burn wounds]

Materials of clinico-bacteriological study of 302 patients with thermal burns of different severity pointed to a considerable elevation of the incidence of Ps. aeruginosa isolation (in cultures) from burn wounds; the last few years it was found in about 50% of the cases. The greater frequency of Ps. aeruginosa detection correlated with the increase of the severity of the affection. By using Soviet set of 17 type agglutinating sera it was possible to type almost 90% of the Ps. aeruginosa cultures isolated from the wounds; a marked prevalence (over 70% of the strains) of cultures belonging to the serological group II was revealed. Patients admitted to the burn centre at early periods after the trauma displayed infection of the wound with the Ps. aeruginosa strain of the II serological group.     

幽门螺杆菌感染和抗菌治疗对食道下端菌群的影响

目的通过小鼠动物模型,探讨幽门螺杆菌（Helicobacter pylori,H.pylori）感染和用抗生素抗H.pylori治疗对食道下端菌群的影响,分析其与食道下端疾病发生的关系。方法将45只Balb/c小鼠随机均分为阴性对照组,感染组和治疗组。感染组和治疗组通过灌喂H.pylori建立动物感染模型,治疗组再灌喂奥美拉唑,氨苄青霉素,克拉霉素根除H.pylori。三组小鼠均在用抗生素处理后同时处死,取食道下端组织提取细菌的DNA,以原核生物16S rDNA V6区通用引物采用聚合酶链发应-变性梯度凝胶技术（PCR-DGGE）检测,用Quantity One1-DAnalysis software对DGGE图谱进行菌群结构分析,并将DGGE图谱上的组间差异条带用16S rDNA V6区引物分别扩增后,DNA测序,BLAST比对鉴定。结果成功制备了小鼠幽门螺杆菌感染模型,用抗生素有效根除了H.pylori感染。小鼠食道下端DGGE指纹图谱分析显示,各组间条带数量比较差异均有统计学意义（P〈0.05）,多样性指数、丰富度指数差异有统计学意义（0.05〉P〉0.001）,均匀度指数差异无统计学意义（P〉0.05）。菌群聚类分析能很好地在相似性进化树中分开,主成分分析不同组的菌群分别聚集在不同的位置,BLAST比对分析对照组,感染组具有特有细菌。结论食道下端定植着由大量细菌构成的较稳定的菌群,H.pylori感染与治疗后菌群结构有明显变化。     

The role of wounds in the infection of oranges by Penicillium digitatum Sacc

Inocula of spores of Penicillium digitatum in water applied to apparently uninjured skin of oranges do not cause lesions to develop. Addition of citric acid, orange juice, or various extracts of rind had little effect on susceptibility to infection. When spores in water are applied to wounds made between oil vesicles, lesions develop only from wounds that penetrate deeply into the albedo. The flavedo of most oranges seems to be resistant to infection even when damaged, but in a few consignments it showed much less resistance. Increasing the number of conidia in the inoculum caused more lesions to develop but some fruits developed lesions from inocula containing very few spores. The method and timing of spore application to wounds had a considerable effect on the incidence of lesions; emanations from infected fruit had no effect. Lesions developed more rapidly and readily when suspensions of spores in water were applied to wounds in the skin that damaged oil vesicles; wounds as shallow as 0–25 mm allowed lesions to develop.     

Wheeze in preschool age is associated with pulmonary bacterial infection and resolves after antibiotic therapy

Background

Neonates with airways colonized by Haemophilus influenzae, Streptococcus pneumoniae or Moraxella catarrhalis are at increased risk for recurrent wheeze which may resemble asthma early in life. It is not clear whether chronic colonization by these pathogens is causative for severe persistent wheeze in some preschool children and whether these children might benefit from antibiotic treatment. We assessed the relevance of bacterial colonization and chronic airway infection in preschool children with severe persistent wheezing and evaluated the outcome of long-time antibiotic treatment on the clinical course in such children.

Methodology/Principal Findings

Preschool children (n = 42) with severe persistent wheeze but no symptoms of acute pulmonary infection were investigated by bronchoscopy and bronchoalveolar lavage (BAL). Differential cell counts and microbiological and virological analyses were performed on BAL samples. Patients diagnosed with bacterial infection were treated with antibiotics for 2–16 weeks (n = 29). A modified ISAAC questionnaire was used for follow-up assessment of children at least 6 months after bronchoscopy. Of the 42 children with severe wheezing, 34 (81%) showed a neutrophilic inflammation and 20 (59%) of this subgroup had elevated bacterial counts (≥10⁴ colony forming units per milliliter) suggesting infection. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis were the most frequently isolated species. After treatment with appropriate antibiotics 92% of patients showed a marked improvement of symptoms upon follow-up examination.

Conclusions/Significance

Chronic bacterial infections are relevant in a subgroup of preschool children with persistent wheezing and such children benefit significantly from antibiotic therapy.     

Static recipient cells as reservoirs of antibiotic resistance during antibiotic therapy

How does taking the full course of antibiotics prevent antibiotic resistant bacteria establishing in patients? We address this question by testing the possibility that horizontal/lateral gene transfer (HGT) is critical for the accumulation of the antibiotic-resistance phenotype while bacteria are under antibiotic stress. Most antibiotics prevent bacterial reproduction, some by preventing de novo gene expression. Nevertheless, in some cases and at some concentrations, the effects of most antibiotics on gene expression may not be irreversible. If the stress is removed before the bacteria are cleared from the patients by normal turnover, gene expression restarts, converting the residual population to phenotypic resistance. Using mathematical models we investigate how static recipients of resistance genes carried by plasmids accumulate resistance genes, and how specifically an environment cycling between presence and absence of the antibiotic uniquely favors the evolution of horizontally mobile resistance genes. We found that the presence of static recipients can substantially increase the persistence of the plasmid and that this effect is most pronounced when the cost of carriage of the plasmid decreases the cell's growth rate by as much as a half or more. In addition, plasmid persistence can be enhanced even when conjugation rates are as low as half the rate required for the plasmid to persist as a parasite on its own.