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At least 127 records · Page 7Linked to original sources
PubMed2001

Activity of telithromycin, a new ketolide antibacterial, against atypical and intracellular respiratory tract pathogens.

Atypical respiratory pathogens such as Mycoplasma pneumoniae and intracellular pathogens such as Legionella spp. and Chlamydia spp. form a significant proportion of the aetiological agents underlying community-acquired pneumonia (CAP). The clinical signs or radiological features of atypical pneumonia are generally insufficient to predict accurately the pathogen involved; in addition, high costs and a considerable length of time are involved in the identification of atypical pathogens. Treatment is, therefore, most often empirical, and it is important that the activity of antibacterial agents available to treat CAP is sufficiently broad to eradicate infection with both common and atypical bacterial pathogens. Telithromycin (HMR 3647) is the first of a new family of antibacterials, the ketolides, and has been designed specifically for the treatment of community-acquired respiratory tract infections (RTIs). The excellent activity of telithromycin against the respiratory tract bacterial pathogens most commonly associated with community-acquired RTIs, including resistant strains, is well established. This review examines the considerable body of evidence showing that telithromycin also has a high level of activity against atypical and intracellular respiratory tract bacterial pathogens.

Anti-Bacterial Agents↗
PubMed1991

Etiology of acute lower respiratory tract infections in Gambian children: II. Acute lower respiratory tract infection in children ages one to nine years presenting at the hospital.

Seventy-four children ages 1 to 9 years hospitalized because of severe pneumonia were investigated using blood cultures, lung aspirates, nasopharyngeal aspirates, serology and antigen detection procedures. A bacterial infection was identified in 57 (77%), a viral infection was seen in 25 (34%) and 18 (24%) had mixed viral-bacterial infections. The bacterial pathogens most frequently identified were Streptococcus pneumoniae and Haemophilus influenzae found in 61 and 15% of patients, respectively. The viral pathogen most frequently recovered was respiratory syncytial virus (12%). Evidence of Chlamydia pneumoniae strain TWAR and Mycoplasma pneumoniae infection was found in 12 and 4% of cases, respectively. Overall a potential pathogen was identified in 60 (81%) children, with evidence of polymicrobial infection in 30 cases (40.5%). The study provides information on the relative role of different infectious agents in the etiology of severe pneumonia in children in a developing country.

Acute Disease↗
PubMed1989

In vitro adherence of Streptococcus pneumoniae to oropharyngeal cells: enhanced activity and colonization of the upper respiratory tract in patients with recurrent respiratory infections.

In vitro adherence of Streptococcus pneumoniae (S. pneumoniae) to oropharyngeal cells was assessed in 3 age matched groups of 29 subjects. The first group included patients with chronic pulmonary disease and recurrent respiratory infections due to S. pneumoniae or a recent respiratory infection caused by this organism. Patients of the second group has similar underlying pulmonary disease to the first group, but they had no S. pneumoniae respiratory infection for at least the past 3 years. Healthy subjects or patients without underlying pulmonary disease constituted the third group. The mean adherence of S. pneumoniae to oropharyngeal cells was 10.6 +/- 4.7 bacteria (bact.)/cell in the first group, 3.6 +/- 2.8 bact./cell in the second group and 1.9 +/- 2.1 bact./cell in the third group. A significant difference was found (p less than 0.01) when the mean of the first group was compared to those of the second and third groups, whereas there was no significant difference between the means of the second and third groups. In addition, a survey of bacterial colonization of the upper respiratory tract was conducted in all the subjects included in this study. Over 6 months, 5 of the 8 patients in the first group had throat cultures (5 cases) and nasal cultures (3 cases) positive for S. pneumoniae, while no one in the second or third group was a carrier of this bacterium in the upper respiratory tract during the same period. Patients with recurrent or recent respiratory infections caused by S. pneumoniae are characterised by an in vitro enhanced ability of this organism to adhere to their oropharyngeal cells. In vivo, this phenomenon is reflected by an increased susceptibility of the upper respiratory tract to colonization by S. pneumoniae.

Adult↗
PubMed2001

Upper respiratory tract infections.

Acute respiratory infections accounts for 20-40% of outpatient and 12-35% of inpatient attendance in a general hospital. Upper respiratory tract infections including nasopharyngitis, pharyngitis, tonsillitis and otitis media constitute 87.5% of the total episodes of respiratory infections. The vast majority of acute upper respiratory tract infections are caused by viruses. Common cold is caused by viruses in most circumstances and does not require antimicrobial agent unless it is complicated by acute otitis media with effusion, tonsillitis, sinusitis, and lower respiratory tract infection. Sinusitis is commonly associated with common cold. Most instances of rhinosinusitis are viral and therefore, resolve spontaneously without antimicrobial therapy. The most common bacterial agents causing sinusitis are S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus and S. pyogenes. Amoxycillin is antibacterial of choice. The alternative drugs are cefaclor or cephalexin. The latter becomes first line if sinusitis is recurrent or chronic. Acute pharyngitis is commonly caused by viruses and does not need antibiotics. About 15% of the episodes may be due to Group A beta hemolytic streptococcus (GABS). Early initiation of antibiotics in pharyngitis due to GABS can prevent complications such as acute rheumatic fever. The drug of choice is penicillin for 10-14 days. The alternative medications include oral cephalosporins (cefaclor, cephalexin), amoxicillin or macrolides.

Anti-Bacterial Agents↗
PubMed2003

Clinical and laboratory study of newborns with lower respiratory tract infection due to respiratory viruses.

OBJECTIVES: To determine the prevalence of lower respiratory tract infection due to respiratory viruses in the neonatal period at admission to the neonatal intensive care unit and to compare the clinical, laboratory and radiological aspects of the clinical course, according to the etiological agent, in the neonatal period. METHODS: Ninety newborns were studied, from January 1999 to January 2001, with bronchiolitis and/or pneumonia. The newborns were classified into three groups, according to the etiological agent identified initially: viral infection (group A), mixed viral-bacterial infection (group B), and bacterial infection (group C). RESULTS: The virus was identified in 72 newborns (80.0%); the most prevalent was respiratory syncytial virus (RSV) (44.4%), followed by influenza A virus (22.2%). Coughing, wheezing and an interstitial infiltrate were significantly more frequent in newborns with viral infection. Mixed infection was more associated with sepsis. There was a correlation between viral infection and low values of initial and subsequent white blood cell count and C-reactive protein. RSV was the most important virus in these patients. CONCLUSIONS: It was observed that, although the majority of viral respiratory infections had a favorable course, some patients presented a serious and prolonged clinical manifestation, especially when there was concomitant bacterial infection.

Birth Weight↗
PubMed1996

Lower respiratory tract disease.

Lower respiratory tract disease is an important source of poor performance and exercise intolerance in racehorses and middle-aged sport horses. Horses that perform high-intensity exercise are predisposed to development of infectious and noninfectious respiratory disease. Diagnostic aids for investigation of lower respiratory tract disease include thorough thoracic auscultation with rebreathing, endoscopic examination, bronchoalveolar lavage (BAL), and thoracic radiographic examination. The therapeutic approach for horses with lower respiratory tract diseases often can be directed by cytologic evaluation of BAL fluid. Conservative management techniques may reduce the risk or severity of respiratory disease in horses performing high-intensity exercise.

Animals↗
PubMed1976

The respiratory tract immune system in the pig. I. Distribution of immunoglobulin-containing cells in the respiratory tract mucosa.

The number of cells containing immunoglobulins A, G and M in the respiratory tract mucosa of pigs from birth to maturity was assessed using the immunoperoxidase technique. Immunoglobulin-containing cells first appeared at 6-7 days of age and rose rapidly to reach levels at 3-4 weeks similar to those in the adult. IgA-containing cells predominated at all sites in all age groups, although there were significant proportions of cells containing IgM and IgG. Our findings suggest that IgA is transported into secretions via the mixed mucoserous glands of the nasal and tracheobronchial mucosa, and that this route is also operative for colostral IgA absorbed from the gut in the baby pig.

Animals↗
PubMed1999

An update on the pathophysiology of rhinovirus upper respiratory tract infections.

Upper respiratory tract infections are one of the most common infectious diseases in man and are characterized by relatively mild symptoms. However, complications of bacterial super-infection or asthma exacerbations are not seldomly seen. Most upper respiratory tract infections are caused by rhinoviruses. The rhinovirus is a non-enveloped 30 nm RNA-virus with over 100 serotypes that belongs to the Picornaviridae family and only replicates in primates. It is characterized by a single positive stranded genome acting not only as a template for RNA synthesis, but also encoding for a single polypeptide necessary for viral replication. The viral capsid has an icosahedral symmetry and demonstrates deep canyons, with a receptor-binding domain. Rhinoviruses are transmitted mainly via direct- or indirect contact with infected secretions and invade their host by binding to the ICAM-1 receptor on the nasal epithelium. Typical for rhinovirus upper respiratory tract infections are isolated scattered foci of infected epithelium, not showing any striking damage or cytopathic alterations, between large areas of normal epithelium. Today there is still little detailed knowledge on the pathophysiology of common cold, especially on the aspect of cellular migration and defense. A better understanding in mechanisms underlying this cellular response would not only have therapeutical consequences, but may also explain the relationship between viral infectious rhinitis and asthma or atopy. During a rhinovirus infection, a selective neutrophil and monocyte recruitment is observed. In vitro and in vivo data have demonstrated a time-limited, rhinovirus-induced increase in bradykinin, cytokine, chemokine and sICAM-1 concentrations. Epithelial derived proinflammatory cytokines initiate an adhesion cascade and activate T lymphocytes that create a TH1-type cytokine environment within the infected tissue, necessary to eradicate the virus infection. The selective recruitment of neutrophils seems linked to increased concentrations of the chemokine IL-8 and common cold symptoms. It is doubtful that the cytokine-regulated-production of specific neutralising immunoglobulins is necessary for recovery from viral illnesses and presumably only contributes to a late and temporary protection against rhinovirus reinfection. These observations confirm the crucial role that cytokines and mediators play in the pathogenesis of a rhinovirus infection by mediating chemotaxis, transmigration and activation of inflammatory- and immunocompetent cells.

Animals↗
PubMed1988

Cellular defense of the avian respiratory system: effects of Pasteurella multocida on respiratory burst activity of avian respiratory tract phagocytes.

The respiratory tract of healthy chickens contain few free-residing phagocytic cells. Intratracheal inoculation with Pasteurella multocida stimulated a significant (P less than 0.05) migration of cells to the lungs and air sacs of White Rock chickens within 2 hours after inoculation. We found the maximal number of avian respiratory tract phagocytes (22.9 +/- 14.0 x 10(6] at 8 hours after inoculation. Flow cytometric analysis of these cells revealed 2 populations on the basis of cell-size and cellular granularity. One of these was similar in size and granularity to those of blood heterophils. Only this population was capable of generating oxidative metabolites in response to phorbol myristate acetate. The ability of the heterophils to produce hydrogen peroxide, measured as the oxidation of intracellularly loaded 2',7'-dichlorofluorescein, decreased with time after inoculation. These results suggest that the migration of heterophils, which are capable of high levels of oxidative metabolism, to the lungs and air sacs may be an important defense mechanism of poultry against bacterial infections of the respiratory tract.

Animals↗
PubMed2003

Procalcitonin, C-reactive protein and leukocyte count in children with lower respiratory tract infection.

BACKGROUND: Lower respiratory tract infection is the most common infection leading to unnecessary antibiotic treatment in children. Etiologic diagnosis is not immediately achieved, and the pathogen remains unidentified in a large number of cases. Neither clinical nor laboratory factors allow for a rapid distinction between bacterial and viral etiology. The aim of our study was to evaluate the reliability of procalcitonin (PCT), C-reactive protein (CRP) and leukocyte count in distinguishing pneumococcal, atypical and viral lower respiratory tract infection. METHODS: PCT, CRP and leukocyte count were measured in children with microbiologically documented diagnoses of lower respiratory tract infection. The results were compared of children with pneumococcal, atypical and viral etiologies. RESULTS: PCT and CRP showed significant correlation with a bacterial etiology of lower respiratory tract infection. No significance was found for leukocyte count. Using a cutoff point of 2 ng/ml for PCT and 65 mg/l for CRP, the sensitivities and specificities for distinguishing bacterial from viral lower respiratory tract infections were 68.6 and 79.4% for PCT and 79.1 and 67.1% for CRP. The sensitivities and specificities for distinguishing pneumococcal from other etiologies were 90.3 and 74.1% for PCT and 90.3 and 60% for CRP, respectively. CONCLUSIONS: High PCT and CRP values show a significant correlation with the bacterial etiology of lower respiratory tract infection. PCT and CRP show good sensitivity for distinguishing pneumococcal from other etiologies. PCT shows higher specificity than CRP. PCT and CRP can help make decisions about antibiotic therapy in children with lower respiratory tract infections.

Biomarkers↗