Microbial flora variations in the respiratory tract of mice

Gutierrez, Rosa Cangemi de; Nader, Olga M. de; Holgado, A. Pesce De Ruiz; Nader‐Macías, María Elena Fátima

doi:10.1590/s0074-02761999000500027

Cited by 10 publications

(14 citation statements)

References 16 publications

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“…In addition to being a significant clinical pathogen, K. pneumoniae is also a normal component of the upper respiratory and GI-tract microbiota of both humans and mice [17–19]. We have previously characterized two human clinical K. pneumoniae isolates (strains 43816 and IA565) that differ significantly in their in vivo pathogenicity in a murine model of acute bacterial pneumonia [20].…”

Section: Introductionmentioning

confidence: 99%

Host and microbiota factors that control Klebsiella pneumoniae mucosal colonization in mice

Lau

Huffnagle

Moore

2008

Microbes and Infection

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Klebsiella pneumoniae is both an opportunistic pathogen and a commensal organism. We have previously reported that K. pneumoniae strain IA565 (KpIA565) is nonpathogenic in a murine model of acute pneumonia. In this study, KpIA565 was inoculated into wild-type mice and found to stably colonize and persist in the nasal cavity and gastrointestinal tract of mice for up to 3 weeks postinoculation. Intranasal inoculation of wild-type or germ-free mice with KpIA565 resulted in similar bacterial levels in the nasal cavity, suggesting KpIA565 nasal colonization is independent of normal nasal microbiota. In contrast, KpIA565 gastrointestinal tract colonization was significantly higher in germ-free mice than in wild-type mice, indicating that members of the endogenous microbiota regulate KpIA565 colonization. In the presence of non-specific dextran sodium sulfate-induced inflammation, KpIA565 gastrointestinal tract colonization was significantly higher when compared to non-DSS treated mice. Interestingly, KpIA565 colonization was unaffected by Citrobacter rodentium-induced gastrointestinal tract inflammation. However, gastrointestinal tract colonization with K. pneumoniae strain IA565 had no impact on the inflammatory histopathology in either colitis model. This study is the first to identify and describe mechanisms influencing the growth and behavior of a murine commensal strain of K. pneumoniae.

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Section: Introductionmentioning

confidence: 99%

Host and microbiota factors that control Klebsiella pneumoniae mucosal colonization in mice

Lau

Huffnagle

Moore

2008

Microbes and Infection

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“…L. fermentum was isolated from the respiratory tract (pharynx) of adult BALB/c mice [18,20-22]. The mutants resistant to Rifampicin (RR) were obtained to differentiate the inoculated strains from the normal microbiota.…”

Section: Methodsmentioning

confidence: 99%

“…The mutants resistant to Rifampicin (RR) were obtained to differentiate the inoculated strains from the normal microbiota. The conditions of storage and culture were described previously [18,20-22]. S. pneumoniae A6 serotype was isolated from human pneumonia-suffering subjects, and identified by standard techniques.…”

Section: Methodsmentioning

confidence: 99%

“…In previous papers, the isolation and identification of the microorganisms of the normal microbiota of the respiratory tract of mice was reported by our research group. Also, the evolution from the moment they were born up to two months age was published [18]. In the isolated microorganisms, the probiotic or beneficial characteristics were studied, selecting some strains of the genus Lactobacillus that shared some properties [19].…”

Section: Introductionmentioning

confidence: 99%

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Effect of Ampicillin on the kinetics of colonization of Streptococcus pneumoniae and Lactobacillus fermentum in the respiratory tract of mice

Gutierrez

Santos

Cecilia

et al. 2004

Ann Clin Microbiol Antimicrob

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Ampicillin was selected to further study the effect of this antibiotic on the colonization capability of S. pneumoniae and L. fermentum intranasally inoculated in a mice experimental model. The sensitivity of S. pneumoniae and L. fermentum to antibiotics was evaluated by different "in vitro" techniques. The results showed that both microorganisms have a typical pattern of sensitivity to antibiotics in these assays. The "in vivo" experiments showed that the treatment with Ampicillin increased the number of lactobacilli and neumococci in the groups of mice treated only with one of the microorganisms. In those mice treated with Lactobacillus, challenged later with neumococci and treated with Ampicillin, the pathogen in lung decreased on the 4th day, disappearing completely after on. The histological studies showed that the antibiotic treatment decreased the inflammatory response produced by the pathogen at the lung and trachea levels.

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“…The composition of the flora and the numbers of different organisms are various, but for a given host, the flora remains fairly constant with time [4]. A stable microbial system in the respiratory tract acts as a defense mechanism against pathogenic microorganisms.…”

Section: Host Factorsmentioning

confidence: 99%