Bacterial flora of the respiratory tracts in chickens with a particular reference to Lactobacillus species.

The effects of three different types of breeding such as isolator, floor, and cage breedings on the bacterial flora of the respiratory tracts (nasal cavity, tongue, pharygolarynx, trachea and air sac) in chickens were determined. Total viable bacterial numbers on the nasal mucus of chickens in the isolator breeding as control group (Group A) aged of 14 days were 10(4.6)/g of autopsy specimen (wet weight), 10(5.7)/g of sample in the cage breeding (Group B) aged of 28 days, and 10(7.0)/g of sample in the floor breeding (Group C) aged of 28 days. Staphylococci and micrococci were predominant bacteria in the nasal cavities of all groups. Total viable numbers of tongue and pharygolarynx were from 10(5.4) to 10(6.5)/g of autopsy specimen. Lactobacilli were the predominant bacteria in pharyngolarynx of chickens. The incidence of staphylococci and micrococci in trachea was lower than those in the another regions. Staphylococci and micrococci dominated in the air sacs of two groups (B and C), but the number and incidence of lactobacilli in the air sacs of chickens were lower than those in the another respiratory tracts. The only clostridia isolation in the air sacs of Group A was observed. A total of 75 strains of Lactobacillus species was isoalted from all respiratory organs and intestine of chickens. These strains were divided into 19 groups. Lactobacillus salivearius subsp. salivarius was the predominant lactobacilli isolated from tongue and pharyngolarynx. Most of isolates from the chicken intestines were mainly identified as the L. acidophilus group and L. reuteri.(ABSTRACT TRUNCATED AT 250 WORDS)