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PubMed2006

A Review of New Fluoroquinolones : Focus on their Use in Respiratory Tract Infections.

The new respiratory fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, and on the horizon, garenoxacin) offer many improved qualities over older agents such as ciprofloxacin. These include retaining excellent activity against Gram-negative bacilli, with improved Gram-positive activity (including Streptococcus pneumoniae and Staphylococcus aureus). In addition, gatifloxacin, moxifloxacin and garenoxacin all demonstrate increased anaerobic activity (including activity against Bacteroides fragilis). The new fluoroquinolones possess greater bioavailability and longer serum half-lives compared with ciprofloxacin. The new fluoroquinolones allow for once-daily administration, which may improve patient adherence. The high bioavailability allows for rapid step down from intravenous administration to oral therapy, minimizing unnecessary hospitalization, which may decrease costs and improve quality of life of patients. Clinical trials involving the treatment of community-acquired respiratory infections (acute exacerbations of chronic bronchitis, acute sinusitis, and community-acquired pneumonia) demonstrate high bacterial eradication rates and clinical cure rates. In the treatment of community-acquired respiratory tract infections, the various new fluoroquinolones appear to be comparable to each other, but may be more effective than macrolide or cephalosporin-based regimens. However, additional data are required before it can be emphatically stated that the new fluoroquinolones as a class are responsible for better outcomes than comparators in community-acquired respiratory infections. Gemifloxacin (except for higher rates of hypersensitivity), levofloxacin, and moxifloxacin have relatively mild adverse effects that are more or less comparable to ciprofloxacin. In our opinion, gatifloxacin should not be used, due to glucose alterations which may be serious. Although all new fluoroquinolones react with metal ion-containing drugs (antacids), other drug interactions are relatively mild compared with ciprofloxacin. The new fluoroquinolones gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin have much to offer in terms of bacterial eradication, including activity against resistant respiratory pathogens such as penicillin-resistant, macrolide-resistant, and multidrug-resistant S. pneumoniae. However, ciprofloxacin-resistant organisms, including ciprofloxacin-resistant S. pneumoniae, are becoming more prevalent, thus prudent use must be exercised when prescribing these valuable agents.

Anti-Infective Agents↗
PubMed1999

[Study of the carrying of respiratory tract viruses in steroid-responsive and simple nephrotic syndrome].

This study aimed to investigate the relationship between the carrying of respiratory tract viruses and the quantitative change of urinary protein of the steroid-responsive and simple nephrotic syndrome (SRSNS), and to assess the function of respiratory tract viruses in the triggering of the SRSNS, 37 children with nephrotic syndrome underwent the examination of respiratory tract viruses (APAAP method) once a week when they were hospitalized from August 1997 to March 1998. Among them, 17 children had simple nephrotic syndrome and 10 had nephritic nephrosis. Moreover, 18 children with respiratory infection in the same season were chosen as the control and were subjected to the examination of respiratory tract viruses by the same method. In the cases of SRSNS, the percentage for the carrying of respiratory tract viruses increases obviously in the acme, the percentage for the carrying of respiratory tract viruses of SRSNS has close relationship with the quantity of urinary protein (P < 0.05). There is no difference between the constitution of the category of the viruses carried in the acme of SRSNS and that of the viruses in the control (P > 0.05). The most frequently detected respiratory tract viruses in the acme of SRSNS is RNA virus, and that in the control is the same (P > 0.05). In the acme of SRSNS, most children have no symptoms of respiratory infection although respiratory tract viruses were detected. In the SRSNS, the percentage for the carrying of respiratory tract viruses increases obviously in the acme, it has an important relationship with the quantitative change of urinary protein. The category of the respiratory tract viruses detected in the SRSNS has a relationship with the season, this may be the reason why the cases of SRSNS so easily happen and relapse in this season. RNA virus perhaps plays an important role in the triggering of this disease, including the respiratory tract viruses infection and the carrying of respiratory tract viruses without the symptom of respiratory infection.

Carrier State↗
PubMed2003

Immunology of viral respiratory tract infection in infancy.

Respiratory viruses such as respiratory syncytial virus (RSV), parainfluenza viruses (PIV) and the influenza viruses cause severe lower respiratory tract disease in infants and children throughout the world. We discuss the recent discovery of the epidemiologic importance of the human metapneumoviruses, first reported in 2001. Experimental live-attenuated vaccines for each of these viruses are being developed for intranasal administration in the first weeks or months of life. The immunology of these infections in humans is poorly defined but many studies are ongoing. A significant obstacle to successful immunisation of infants against respiratory-virus-associated disease early in life may be the relatively poor immune response of very young infants to primary virus infection. This paper reviews the immune correlates of protection against disease caused by these viruses, immune responses of infants to naturally acquired infection or experimental infection with candidate vaccine viruses and the genetics of susceptibility to severe disease.

Animals↗
PubMed1976

Vaccine and Mycostatin in treatment of cryptococcosis of the respiratory tract.

Three cases of respiratory crytococcosis are described, one diagnosed only after thoracotomy and two after cytology. All were confirmed by cultures, biological and biochemical tests. The patients are alive and well 14 years, 5 years, and 5 years after treatment with crytococcal vaccines and mycostatin. Vaccines proved very effective when given intradermally in small doses and no dangerous reactions were encountered. Cytology of the sputum appears to be a very useful tool in diagnosis of fungal infections of the respiratory tract, especially when supravital staining is used. Difficulties in diagnosis, treatment, and significance of positive sputum findings are discussed.

Adult↗
PubMed1999

Developmental mucin gene expression in the human respiratory tract.

The epithelial surface of the respiratory tract is coated with a protective film of mucus secreted by epithelial goblet and submucosal gland cells. Histology of the airway mucosa and composition of secretions during the second trimester of fetal life are known to differ from the normal adult in that these secretions show similarities with those of hypersecretory disorders. To provide information regarding cell-specific expression of mucin genes and their relation to developmental patterns of epithelial cytodifferentiation, we studied the expression of eight different mucin genes (MUC1-MUC4, MUC5AC, MUC5B, MUC6, MUC7) in human embryonic and fetal respiratory tract using in situ hybridization. These investigations demonstrated that MUC4 is the earliest gene expressed in the foregut at 6.5 wk, followed by MUC1 and MUC2 from 9. 5 wk of gestation in trachea, bronchi, epithelial tubules, and terminal sacs before epithelial cytodifferentiation. In contrast, MUC5AC, MUC5B, and MUC7 are expressed at later gestational ages concomitant with epithelial cytodifferentiation. During this developmental stage, MUC1 and MUC4 mRNAs are located in goblet and ciliated cells, whereas MUC2 mRNAs are located in basal and goblet cells. MUC5AC expression is confined to goblet cells. In the submucosal glands, MUC2 mRNAs are located in both mucous and serous cells, whereas MUC5B and MUC7 mRNAs are expressed in mucous and in serous cells, respectively. These data suggest distinct developmental roles for MUC1, MUC2, MUC4, MUC5AC, MUC5B, and MUC7 in the elongation, branching, and epithelial cytodifferentiation of the respiratory tract during ontogenesis. Distinct patterns of mucin gene expression are also likely to play an important role in regulating appropriate epithelial cell proliferation and cytodifferentiation in adult airway mucosa as it is indicated by aberrant expression in hypersecretory disorders.

Adult↗
PubMed2001

Barriers to the effective management of respiratory tract infections in the community.

The treatment of respiratory tract infections (RTIs) continues to challenge the knowledgeable and conscientious physician. Upper RTIs such as sinusitis and tonsillitis/pharyngitis - while not generally life-threatening - are associated with personal cost and suffering, while infections of the lower respiratory tract, including community-acquired pneumonia (CAP) and acute exacerbations of chronic bronchitis (AECB), represent a more serious clinical challenge and account for almost half of all community-acquired infections. Moreover, such infections may be fatal. Laboratory tests for etiologic agents of RTIs are often insensitive and slow and identify the causative pathogen in only a minority of cases. Therapy for RTIs is, therefore, generally presumptive and instituted before there is a clear understanding of etiology. Such an approach requires antibacterials that possess a spectrum of activity which covers both the common and atypical/intracellular pathogens associated with RTIs to enable physicians to confidently prescribe treatment. A major barrier to the confident prescribing of empiric therapies for RTIs is the increasing prevalence of resistance to existing antibacterial agents among respiratory tract pathogens. Increasing levels of antibacterial resistance now threaten the utility of existing agents, primarily the beta-lactams and macrolides, and continue to drive the search for newer agents which retain activity against drug-resistant respiratory tract pathogens. This need is emphasized by recent evidence that bacterial resistance may be associated with poorer clinical outcomes, particularly for patients with severe infections. There is enormous concern and uncertainty about the factors that contribute to increasing bacterial resistance and treatment strategies that should be adopted to minimize this problem. The arguments have raged particularly around recent Infectious Diseases Society of America (IDSA) guidelines on the treatment of CAP, which have advocated a greater role for fluoroquinolones. One school of thought - driven in part by concerns over cost of therapy - advocates the use of older agents such as amoxicillin, in the hope that any resistance that is incurred will be to these agents, leaving the newer agents for select cases with acquired resistance. Advocates of the newer agents argue that this approach represents a false economy and that there is a greater likelihood of first-line success with newer agents, so that patients are less likely to require a second physician visit and a second course of antibacterial therapy.

Anti-Bacterial Agents↗
PubMed2001

Diagnosis and management of respiratory tract infections for the primary care physician.

Respiratory tract infections cause nearly half of deaths owing to infectious disease in the United States. This article has discussed the management of several common respiratory tract infections, with an emphasis on appropriate diagnosis and use of antimicrobial agents. Understanding the cause of various respiratory tract infections enables primary care physicians to avoid unnecessary antibiotic use, decreasing adverse effects owing to medications and preventing the rise in antimicrobial resistance.

Acute Disease↗
PubMed1993

Upper respiratory tract infections in children.

Respiratory tract infections are a frequent problem for children, families, and pediatricians. Most such infections are trivial and do not warrant significant concern; however, for some children and some infections, aggressive and effective therapy is important. Much of the literature discussed in this article reflects attempts to clarify and improve appropriate use of antimicrobial therapy for those children in whom it is necessary.

Anti-Bacterial Agents↗
PubMed1992

Impact on mortality of a community-based programme to control acute lower respiratory tract infections.

Acute lower respiratory tract infections (ALRIs) are a major cause of death among young children in developing countries. A targeted programme designed to treat children with ALRI was implemented in 1988 in a primary health care project in rural Bangladesh. In the 2 years preceding the introduction of the programme (1986-87), non-ALRI-specific health services were provided, including promotion of oral rehydration therapy, family planning, immunization of children and mothers, distribution of vitamin A, referral of severely sick children to field clinics, and nutritional rehabilitation of malnourished children. The targeted ALRI programme, which was in place in 1988-89, was based on systematic ALRI case detection and management by community health workers, who were linked to a referral system for medical support. These two levels of intervention have been evaluated by comparing the ALRI-specific mortality in the programme area and a neighbouring control area during the two periods. During the first phase (1986-87), the ALRI mortality among under-5-year-olds was 28% lower in the intervention than in the comparison area (P less than 0.01). During the second phase (1988-89), the ALRI mortality was 32% lower in the intervention area than during the preceding phase, while there was no significant difference for the comparison area. These findings suggest that in the study region the combination of specific and nonspecific interventions can reduce ALRI mortality by as much as 50% and the overall mortality among under-5-year-olds by as much as 30%.

Allied Health Personnel↗
PubMed2006

Diagnostic value of signs, symptoms and laboratory values in lower respiratory tract infection.

BACKGROUND: Lower respiratory tract infections (LRTI) account for the majority of all antibiotics prescribed in the clinical practice, irrespective of the fact that most cases are self-limiting. Using the outcome and microbiology findings as gold standard, we determined sensitivity, specificity, positive and negative predictive values of common used signs and symptoms of bacterial LRTI requiring antibiotic therapy. PATIENTS: 243 consecutive patients with suspected LRTI admitted to a tertiary care hospital. RESULTS: Bacterial LRTI requiring antibiotic therapy and self-limiting LRTI were diagnosed in 32 and 86 patients, respectively. Assessing these two groups, sputum, dyspnea, crackles, fever and leukocytes (WBC) were insensitive and unspecific parameters for the diagnosis of bacterial LRTI requiring antibiotic therapy. Cough was sensitive (93.8%) but unspecific (5.8%). The sensitivity of infiltrates, C-reactive protein (CRP) >50 mg/L and procalcitonin (PCT) >0.1 ng/mL was 96.9%, 93.8% and 93.8%, respectively. PCT >0.25 ng/mL showed the highest specificity (97.7%), followed by WBC >16 x 109/L (94.2%) and CRP >100 mg/L (91.9%). The sensitivity of WBC >16 x 109/L was low (37.5%). CONCLUSION: The overall sensitivity and specificity of signs and symptoms for bacterial LRTI requiring antibiotic therapy was poor. Obtaining a chest-X-ray with infiltrates and determining CRP at a cut-off value of 50 mg/L or PCT at a cutoff value of 0.1 ng/mL was required to ascertain the need for antibiotics in LRTI.

Adolescent↗
PubMed2003

Patients' responses to delayed antibiotic prescription for acute upper respiratory tract infections.

BACKGROUND: Upper respiratory tract infections (URTIs) account for approximately 50% of antibiotic prescriptions in the United Kingdom. General practitioners (GPs) frequently issue such prescriptions simply because they believe that the patient expects it. Deferred prescribing (issuing a prescription, but with instructions to wait for no spontaneous improvement before deciding whether to use it) might address patients' expectations, while minimising actual antibiotic consumption. Although the technique is quite widely practiced, patients' attitudes and responses to it are unclear. AIMS: To establish the proportion of recipients who claim to consume their delayed antibiotic prescriptions. To elicit factors associated with patients' decisions to consume their antibiotics, and patients' confidence in taking this decision. DESIGN OF STUDY: Postal questionnaire survey. SETTING: Patients from 13 group practices in the south of England. METHODS: Patients who had received a delayed antibiotic prescription for URTI from their GP were posted a questionnaire 2 days after their consultation. RESULTS: Three hundred and seventy-four subjects were recruited of whom 256 (68.4%) returned their questionnaires. Just over half (53.1%) of the responders claimed to have consumed their antibiotics. The majority of patients (87.1%) were confident about taking the decision as to whether to use their antibiotics, and 92.5% would choose to receive a delayed prescription again. Subjects were more likely to take their antibiotics if their presenting symptoms included a fever or sinus pain. CONCLUSION: Most patients are confident in making the decision about whether or not to take their antibiotics when receiving a delayed prescription for URTIs. Antibiotic consumption is associated with presenting symptoms, and this has implications for future practice.

Adolescent↗
PubMed1993

Association of microbiologic flora with clinical, endoscopic, and pulmonary cytologic findings in foals with distal respiratory tract infection.

Undifferentiated distal respiratory tract disease (nasal discharge, cough, pneumonia) in foals (1 to 8 months old) is a burdensome economic problem on breeding farms; yet, the infective agents associated with these episodes have not been well described. Possible causes of these episodes of illness were investigated by culturing specimens of proximal and distal airways of clinically diseased foals (n = 101), prior to any treatment, for aerobic and anaerobic bacteria and viruses (rhinoviruses, equine arteritis virus, equine herpesvirus subtype 1 [EHV-1], influenza virus, and adenovirus). Pairs of sera (n = 47) were examined for antibodies to influenza A virus, equine subtypes 1 and 2, EHV-1, and adenovirus antigens, and sera obtained from foals during acute infection were examined for antibodies (by agar gel immunodiffusion [AGID]) to equi factor antigens of Rhodococcus equi. Viruses were not isolated from the proximal (swab) or distal (bronchial lavage) airway specimens in foals, and only 2 of 47 randomly selected foals seroconverted to EHV-1. Serotiters to the other viruses were low and frequently decreasing between samples, which was compatible with maternally derived antibody. Streptococcus zooepidemicus was the predominant isolate from bronchial lavage specimens (88/101 cases), accompanied by alpha-hemolytic streptococci (8 cases), Bordetella bronchiseptica (13 cases), Staphylococcus epidermidis (9 cases), and other organisms in lesser frequency. Only Str zooepidemicus was recovered significantly (P < 0.05) more often in cases than in controls. The AGID test was found useful to detect foals with presumed exposure to R equi, but positive tests results did not correspond well with bacterial culture results; positive AGID results were recorded in 34% of culture-negative foals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Association between antibiotic prescribing and visit duration in adults with upper respiratory tract infections.

BACKGROUND: Upper respiratory tract infections (URTIs) are the most common reason for individuals to seek health care in the United States. Inappropriate antibiotic use exposes patients unnecessarily to potential adverse events and increases the prevalence of antibiotic-resistant bacteria. One of the reasons physicians may prescribe an antibiotic inappropriately is to save time. OBJECTIVE: The aim of this study was to determine whether there is an association between antibiotic use and a shorter visit duration in adults with URTIs. METHODS: Visits to office-based primary care physicians made by adults aged 18 to 60 years from 1995 through 2000 were extracted from the National Ambulatory Medical Care Survey. Visits that resulted in a primary diagnosis of acute URTI; acute nasopharyngitis; acute bronchitis; sinusitis; streptococcal sore throat, acute pharyngitis, or acute tonsillitis; or otitis media were included in the study. Visits associated with >1 diagnosis were included in a separate category Visit duration was defined as the face-to-face time between the patient and physician. RESULTS: There were 3764 visits that met the criteria for inclusion in this study, representing an estimated 27 million annual visits to office-based primary care physicians by adults with URTIs. Antibiotics were prescribed in 67% of visits. The mean visit duration associated with prescription of an antibiotic was 14.2 minutes, compared with 15.2 minutes without prescription of an antibiotic (P = 0.007). In multivariable modeling, independent predictors of visit duration were calendar year (additional 0.3 minute per year; 95% CI, 0.1 to 0.6), internal medicine specialty (additional 2.2 minutes vs family practice; 95% CI, 1.3 to 3.1), covisit with a nurse-practitioner or physician assistant (6.6 minutes shorter; 95% CI, -2.7 to -10.6), and Midwestern location of practice (1.1 minutes shorter vs Northeast; 95% CI, -0.1 to -2.2). Antibiotic use was marginally associated with a shorter visit duration (0.7 minute shorter; 95% CI, 0.0 to -1.3; P = NS). CONCLUSIONS: In the present study, antibiotic use was marginally associated with a shorter visit duration for adults with URTIs. Any potential efficiencies gained by physicians through prescribing antibiotics for adults with URTIs are likely to be outweighed by increases in antimicrobial resistance and exposure of patients to unneeded medication.

Adolescent↗
PubMed1989

Changes in epithelial secretory cells and potentiation of neurogenic inflammation in the trachea of rats with respiratory tract infections.

In rats respiratory tract infections due to Sendai virus and coronavirus usually are transient, but they can have long-lasting consequences when accompanied by Mycoplasma pulmonis infections. Morphological alterations in the tracheal epithelium and a potentiation of the inflammatory response evoked by sensory nerve stimulation ("neurogenic inflammation") are evident nine weeks after the infections begin, but the extent to which these changes are present at earlier times is not known. In the present study we characterized these abnormalities in the epithelium and determined the extent to which they are present 3 and 6 weeks after the infections begin. We also determined the magnitude of the potentiation of neurogenic inflammation at these times, whether the potentiation can be reversed by glucocorticoids, and whether a proliferation of blood vessels contributes to the abnormally large amount of plasma extravasation associated with this potentiation. To this end, we studied Long-Evans rats that acquired these viral and mycoplasmal infections from other rats. We found that the tracheal epithelium of the infected rats had ten times as many Alcian blue-PAS positive mucous cells as did that of pathogen-free rats; but it contained none of the serous cells typical of pathogen-free rats, so the total number of secretory cells was not increased. In addition, the epithelium of the infected rats had three times the number of ciliated cells and had only a third of the number of globule leukocytes. In response to an injection of capsaicin (150 micrograms/kg i.v.), the tracheas of the infected rats developed an abnormally large amount of extravasation of two tracers, Evans blue dye and Monastral blue pigment, and had an abnormally large number of Monastral blue-labeled venules, particularly in regions of mucosa overlying the cartilaginous rings. This abnormally large amount of extravasation was blocked by dexamethasone (1 mg/day i.p. for 5 days). We conclude that M. pulmonis infections, exacerbated at the outset by viral infections, result within three weeks in the transformation of epithelial serous cells into mucous cells, the proliferation of ciliated cells, and the depletion of globule leukocytes. They also cause a proliferation of mediator-sensitive blood vessels in the airway mucosa, which is likely to contribute to the potentiation of neurogenic inflammation that accompanies these infections.

Animals↗
PubMedDate not supplied

A community-based study of acute respiratory tract infections in children in Uruguay.

Acute respiratory tract infection (ARI) was investigated in children less than 5 years old in a longitudinal community-based study of 166 families living in a socioeconomically depressed area in Montevideo, Uruguay. Pediatricians made home visits every 10 days from May 1985 to December 1987, and symptoms and signs of ARI were recorded. The incidence of ARI was 5.8 episodes per child-year during the first 12 months of life and decreased with increasing age of the index children; the rate was highest in children 1-5 months old. Children observed from birth were ill during 21% of the visits. According to the definitions of the study, the incidence of lower respiratory tract infection was 11.6% higher than the incidence of upper respiratory tract infections. The rates of ARI were higher during the colder months. Most risk factors for ARI were only marginally statistically significant.

Acute Disease↗
PubMed2006

Diagnostic value of real-time polymerase chain reaction to detect viruses in young children admitted to the paediatric intensive care unit with lower respiratory tract infection.

INTRODUCTION: The aetiology of lower respiratory tract infections in young children admitted to the paediatric intensive care unit (PICU) is often difficult to establish. However, most infections are believed to be caused by respiratory viruses. A diagnostic study was performed to compare conventional viral tests with the recently developed real-time PCR technique. METHOD: Samples from children aged under 5 years presenting to a tertiary PICU suspected of having a lower respiratory tract infection were tested using conventional methods (viral culture and immunofluorescence) and real-time PCR during the winter season from December 2004 to May 2005. Conventional methods were used to check for respiratory syncytial virus, influenzavirus, parainfluenzavirus 1-3, rhinoviruses and adenoviruses. Real-time PCR was used to test for respiratory syncytial virus, influenzavirus, parainfluenzavirus 1-4, rhinoviruses, adenoviruses, human coronaviruses OC43, NL63 and 229E, human metapneumovirus, Mycoplasma pneumoniae and Chlamydia pneumoniae. RESULTS: A total of 23 patients were included, of whom 11 (48%) were positive for a respiratory virus by conventional methods. Real-time PCR confirmed all of these positive results. In addition, real-time PCR identified 22 more viruses in 11 patients, yielding a total of 22 (96%) patients with a positive sample. More than one virus was detected in eight (35%) children. CONCLUSION: Real-time PCR for respiratory viruses was found to be a sensitive and reliable method in PICU patients with lower respiratory tract infection, increasing the diagnostic yield twofold compared to conventional methods.

Child, Preschool↗
PubMed2004

Colonization capability of lactobacilli and pathogens in the respiratory tract of mice: microbiological, cytological, structural, and ultrastructural studies.

Respiratory tract infections are among the bacterial infections that affect humans with higher frequency. Those produced by Streptococcus pneumoniae are reported to have the highest incidence in the world, affecting both children and old people. As a 2001 report from the World Health Organization expressed it, the basic fight of children under 5 yr old is to survive. Five different conditions (acute respiratory infections, diarrhea, measles, palludism, and undernutrition) directly produce more than 50% of the deaths in this age group. Respiratory tract infections in the developing countries in the Americas are among the first three causes of death in children under 1 yr and between the first and second cause in children between 1 and 4 yr old. Pneumonia is responsible for 85 and 90% of deaths in children under 5 yr old (approx 150,000 annually), 95% of them occurring in the developing countries in the Americas. There is an increased worldwide tendency to use preventive measures and to consume products that help to maintain the health status of the individual. Thus the use of probiotics has increased systematically during the last decade, and the scientific literature trying to demonstrate the positive effect of such preparations has also increased. The term probiotic has been applied to products that (1) contain live microorganisms, freeze-dried or included in fermented products or (2) improve the health status of humans and animals, exerting effects in the mouth or gastrointestinal tract (included in foods or capsules), in the respiratory tract (as aerosols), or in the urogenital tract (by local application)Having in mind the high incidence of respiratory tract infections, and looking for preventive measures as well as the possible applications of probiotics, the aim of this chapter was to use mice as experimental models to determine whether members of the genus Lactobacillus were able to colonize and give protection from infections after inoculation by the intranasal route. To this end, the following procedures were carried out: 1. Screening of the predominant bacterial species in respiratory organs. 2. Study of the kinetics of colonization of the different groups of microorganisms from 15 d up to adult (2 mo). 3. Screening of the probiotic characteristics of all the isolated strains.

Animals↗