Anaerobic bacteria in upper respiratory tract and head and neck infections: microbiology and treatment

Anaerobes are the predominant components of oropharyngeal mucous membranes bacterial flora, and are therefore a common cause of bacterial infections of endogenous origin of upper respiratory tract and head and neck. This review summarizes the aerobic and anaerobic microbiology and antimicrobials therapy of these infections. These include acute and chronic otitis media, mastoiditis and sinusitis, pharyngo-tonsillitis, peritonsillar, retropharyngeal and parapharyngeal abscesses, suppurative thyroiditis, cervical lymphadenitis, parotitis, siliadenitis, and deep neck infections including Lemierre Syndrome. The recovery from these infections depends on prompt and proper medical and when indicated also surgical management.     

Use of spiramycin in the treatment of inflammatory diseases ot the respiratory tract in children in ambulatory conditions]

Comparative efficacy of oral spiramycin and ampicillin was estimated in the treatment of 65 children at the age of 5 to 12 years with infectious inflammatory diseases of the respiratory tract, tonsils and middle ear. By the 7th day of the treatment with spiramycin the cure was stated in 97.7 per cent of the patients and 2.3 per cent of the patients showed the improvement. With the use of ampicillin the cure was recorded only by the 12th day. Marked advantages of spiramycin were observed as well with respect to the time course of the improvement of the disease main signs such as fever, pain in the throat on swallowing, intoxication and others.     

Resident bacteria contribute to opportunistic infections of the respiratory tract

Opportunistic pathogens frequently cause volatile infections in hosts with compromised immune systems or a disrupted normal microbiota. The commensalism of diverse microorganisms contributes to colonization resistance, which prevents the expansion of opportunistic pathogens. Following microbiota disruption, pathogens promptly adapt to altered niches and obtain growth advantages. Nevertheless, whether and how resident bacteria modulate the growth dynamics of invasive pathogens and the eventual outcome of such infections are still unclear. Here, we utilized birds as a model animal and observed a resident bacterium exacerbating the invasion of Avibacterium paragallinarum (previously Haemophilus paragallinarum) in the respiratory tract. We first found that negligibly abundant Staphylococcus chromogenes, rather than Staphylococcus aureus, played a dominant role in Av. paragallinarum-associated infectious coryza in poultry based on epidemic investigations and in vitro analyses. Furthermore, we determined that S. chromogenes not only directly provides the necessary nutrition factor nicotinamide adenine dinucleotide (NAD⁺) but also accelerates its biosynthesis and release from host cells to promote the survival and growth of Av. paragallinarum. Last, we successfully intervened in Av. paragallinarum-associated infections in animal models using antibiotics that specifically target S. chromogenes. Our findings show that opportunistic pathogens can hijack commensal bacteria to initiate infection and expansion and suggest a new paradigm to ameliorate opportunistic infections by modulating the dynamics of resident bacteria.     

Anaerobic transformation of quercetin-3-glucoside by bacteria from the human intestinal tract

From human feces two phenotypically different types of bacteria were isolated on quercetin-3-glucoside as carbon and energy source. Isolates of one type were identified as strains of Enterococcus casseliflavus. They utilized the sugar moiety of the glycoside, but did not degrade the aglycon further. The sugar moiety (4 mM) was fermented to 5.5 ± 2.1 mM formate, 2.1 ± 0.7 mM acetate, 1.6 ± 0.3 mM l-lactate, and 1.3 ± 0.4 mM ethanol. The second type of isolate was identified as Eubacterium ramulus. This organism was capable of degrading the aromatic ring system. Growing cultures of Eubacterium ramulus converted 5 mM quercetin-3-glucoside to 1.7 ± 0.6 mM 3,4-dihydroxyphenylacetic acid, 7.6 ± 1.0 mM acetate, and 4.0 ± 0.4 mM butyrate. Molecular hydrogen, 3,4-dihydroxybenzaldehyde, and ethanol were detected in small amounts. Phloroglucinol was a transient intermediate in the breakdown of quercetin-3-glucoside. Eubacterium ramulus did not grow on the aglycon quercetin or the ring-fission intermediate phloroglucinol, but cleaved the flavonoid ring system when glucose was present as a cosubstrate. The most probable number of quercetin-3-glucoside-degrading bacteria determined in nine human fecal samples was 10⁷–10⁹/g dry mass. Isolates from these experiments were all identified as Eubacterium ramulus. Received: 9 July 1998 / Accepted: 10 November 1998     

A novel pathway that regulates inflammatory disease in the respiratory tract

In animals with acute airway inflammation followed by repeated exposure to inhaled Ag, inflammation wanes over time and thus limits the study of chronic airway inflammatory diseases such as asthma. We developed a model of airway inflammation and inhalational exposure to investigate regulatory pathways in the respiratory tract. We show that Th1- and Th2-induced airway inflammation followed by repeated exposure to inhaled Ag leads to a state of immunosuppression. Challenge of these animals with a marked population of TCR transgenic effector Th1 or Th2 cells results in a striking inhibition of inflammation and effector Th cells. In Th2 models, airway hyperresponsiveness, mucus, and eosinophilia are reduced. The inhibitory effects observed are Ag nonspecific, can be induced in lymphocyte-deficient mice, and are associated with a population of TGF-beta1-expressing macrophages. Induction of this pathway may offer potent localized treatment of chronic T cell-mediated respiratory illnesses and provide insights into the development of such diseases.     

Anaerobic biodegradation of ethylthionocarbamate by the mixed bacteria under various electron acceptor conditions

Biodegradation behavior and kinetics of ethylthionocarbamate under nitrate, sulfate and ferric reducing conditions by mixed cultures enriched from the anaerobic digester sludge was investigated. The results showed that ethylthionocarbamate could be degraded independently by the mixed cultures coupled to nitrate, sulfate, and ferric reduction, and meanwhile, nitrite, sulfide, and ferrous were accumulated as a result of nitrate, sulfate and ferric reduction, respectively. Ferric was a more favorable terminal electron acceptor compared to nitrate and sulfate. The order of the electron acceptors with decreasing biodegradation rates of the ethylthionocarbamate was: ferric>nitrate>sulfate, and the corresponding maximum biodegradation rate was 7.240, 6.267, and 4.602 mg/(L·d), respectively. The anaerobic biodegradation of ethylthionocarbamate under various electron acceptor conditions can be accurately described by first order exponential decay kinetics.     

Anaerobic bacteria from the digestive tract of North Atlantic fin whales (Balaenoptera physalus)

Abstract Samples were collected from the forestomach and colon of North Atlantic fin whales ( Balaenoptera physalus ) landed at the commercial whaling station at Hvalfjördur, Iceland during three whaling seasons. Techniques were used to enrich for and enumerate anaerobic bacteria, methanogens, and sulfate reducers. Anaerobic bacteria ranged from 10⁸ to 10¹⁰ per ml of digesta in the colon, and from 10⁵ to 10⁹ per ml of digesta in the forestomach. Methanogens and sulfate-reducing bacteria were found in the majority of forestomach and colon samples, with sulfate-reducing bacteria usually occuring at higher concentrations. Enteric bacteria, Vibrio , and Listonella spp. were found in the colon. Volatile fatty acids were detected in significant concentrations in the forestomach of many of the whales. These results support previous findings which suggest that a microbial fermentation occurs in the forestomach of baleen whales.     

Microflora of the upper respiratory tract in young children under normal conditions and in respiratory tract diseases. Microbial count of the upper respiratory tract in healthy children and in children with pneumonia

The results of the inoculation of material taken from the anterior section of the nasal cavity and from the pharyngeal mucosa of 50 healthy young children and 298 acute pneumonia patients were analyzed. 23 microbial species were isolated. In the samples taken from the anterior section of the nasal cavity, monocultures were detected in 86 samples and 54 variants of associations including 2-4 species, in 139 samples. In the samples taken from the pharynx, monocultures were detected in 59 samples and 180 variants of associations including 2-6 species, in 282 samples. Differences in the contamination of the nasal cavity and the pharynx in healthy children and in pneumonia patients were revealed. These differences were manifested in the structure of the microflora (monocultures, associations, their composition), the assortment of microbial species and their concentration. In young children with pneumonia the microflora of the upper respiratory tract was found to reflect the severity of acute pneumonia and the intensity of the pathological process in the lungs (uncomplicated, pyodestructive pneumonia, pyodestructive pneumonia with fatal termination, acute purulent pleurisy).     

Anaerobic bacteria in clinical infections

The findings of 275 cultures from routine clinical specimens obtained from lesions in different sites of body, during a period of 11 months, are presented. The clinical specimens were obtained from surgical wounds, abdominal infections, orthopaedic operations, biliary tract infections and pleuropulmonary infections. The total number of positive cultures including both aerobes and anaerobes was 203 out of 275 (73.8%). Of the 38 cultures positive for anaerobes, 29 (76.3%) grew both aerobic and anaerobic bacteria, while in nine (23.7%) cultures only anaerobes were found. A total of 42 strains of anaerobic bacteria were isolated. The majority of them were found in clinical specimens obtained from abdominal infections (62%), while a low percentage (3.6%) was found in specimens from orthopaedic operations. Strains belonging to the genus Bacteroides were the most frequently isolated anaerobes, accounting for 35.7% of the total, followed by Clostridia 28.5%, Peptostreptococci 23.8% and Prevotella 12%.     

Anaerobic microflora of the female reproductive tract

The microflora of the female reproductive tract is very diverse and plays an important role in both normal and pathological states. The data on the mechanisms of colonization resistance which involve the vaginal microbios (the production of H2O2, organic acids, bacteriocin-like substances, competition for adhesion sites) are presented. The data on the role of individual antagonistically active substances of anaerobic bacteria in suppressing gonococci, fungi, microorganisms, associated with bacterial vaginosis, etc. are given. The leading role of anaerobic microorganisms in the appearance of microecological disturbances, including bacterial vaginosis, is emphasized. The role of the pathogenic properties of anaerobic bacteria for the development of different pathological processes, such as premature birth, postnatal and postoperative purulent septic diseases, inflammation of pelvic organs, cancer of the neck of uterus, is discussed.     

牙周可疑致病菌与下呼吸道感染的关系

牙菌斑生物膜是牙周炎的始动因子。研究发现,牙周炎与全身多器官或系统的感染性疾病有关,如心脑血管疾病、糖尿病、消化道和呼吸道疾病。近年来,牙周炎与呼吸道疾病之间的关系备受关注,本文将近期对牙周可疑致病菌感染下呼吸道的途径及其作用研究做简要综述。     

Anaerobic fecal bacteria of the baboon.

The predominant bacterial genera of baboon feces were enumerated and identified by established procedures. The predominant genera isolated were Lactobacillus, Eubacterium, Streptococcus, and Bacteroides.     

Anaerobic fecal bacteria of the baboon.

The predominant bacterial genera of baboon feces were enumerated and identified by established procedures. The predominant genera isolated were Lactobacillus, Eubacterium, Streptococcus, and Bacteroides.     

Anaerobic dechlorination of carbon tetrachloride by free-living and attached bacteria under various electron-donor conditions

The dechlorination of carbon tetrachloride (CCl₄) by free-living and attached bacteria under anaerobic conditions was studied to examine the relationship between porous media and electron donor. Two batch-type experiments, the free-living and attached bacterial systems, were conducted with and without addition of 0.5-mm glass beads. Glucose and acetate were selected as the primary electron donors because they are easily biodegradable. Direct epifluorescence technology, the DAPI (4′ 6-diamidino-2-phenylindole) method, was used for counting the microbial activities. Adding glass beads could accelerate the dechlorination rate of CCl₄. Removals of 44 %–57 % were observed in free-living bacterial system. Whereas a two- to fivefold increase in the CCl₄ dechlorination rate was observed in the attached system. Experimental results and thermodynamic calculations indicated that glucose is a better supplementary substrate than acetate for stimulating the dechlorinating capability of microorganisms because of its relatively high available free energy. A higher concentration of substrate provided more reducing power for attached bacteria to initiate the dechlorination reaction. The pseudo-first-order rate constants of CCl₄ dechlorination ranged from 0.007 day⁻¹ to 0.017 day⁻¹ and from 0.011 day⁻¹ to 0.0625 day⁻¹ for free-living and attached bacterial systems respectively. Microscopic observation revealed a three- to eightfold difference of microbial number between the free-living and attached bacterial systems. On the basis of the results in this study, we can conclude that the presence of porous media and an electron donor can change the dechlorination capabilities of the microorganisms. This work will be valuable in the design of in situ bioremediation as it discusses the specific area of the medium and supplementation with an electron donor to stimulate the indigenous microflora. Received: 21 June 1996 / Received revision: 2 September 1996 / Accepted: 29 September 1996     

大气细颗粒物影响小鼠上、下呼吸道菌群结构

探讨影响人类健康的大气细颗粒物干扰小鼠上呼吸道和下呼吸道菌群定植及可能机制。

建立大气细颗粒物暴露的小鼠模型。BALB/c小鼠随机分为PM2.5暴露组和对照组, 每组10只。收集上呼吸道和下呼吸道灌洗液进行菌群测序分析, 并进行肺组织HE染色, 观察肺组织形态改变情况。

大气细颗粒物暴露小鼠, 破坏肺组织气血屏障结构。16S rRNA测序证实了上、下呼吸道微生态的组成因大气细颗粒物暴露而发生改变。明确了与细颗粒物暴露组相比较, 对照组的噬几丁质菌定植的丰度较高。

大气细颗粒物影响小鼠上、下呼吸道的微生态结构。研究发现的差异菌群改变将会成为新的肺损伤治疗的潜在菌群。