Separating Mycoplasma gallisepticum Field Strains from Nonpathogenic Avian Mycoplasmas

Abstract

Mycoplasma gallisepticum (MG) has repeatedly emerged as a serious problem in U.S. broiler, layer, and turkey industries. Tracing the source of an outbreak is essential if MG control is to be accomplished. Amplified fragment length polymorphism (AFLP), random amplification of polymorphic DNA (RAPD), and restriction fragment length polymorphism (RFLP) are valuable tools used to study MG epidemiology, allowing diagnosticians to determine the source of MG infections. In some past outbreaks, AFLP, RAPD, and RFLP fingerprinting, which require pure MG cultures, were not successful because of contaminating nonpathogenic mycoplasmas from field samples. The objective of this research was to develop a method to separate rapidly growing nonpathogenic avian mycoplasma species from slower-growing MG field strains. Mixtures of MG and three separate nonpathogenic avian mycoplasmas were inoculated onto chick embryo fibroblasts cells (CEF) allowing MG to penetrate the CEF cells. Later, gentamicin sulphate was added to the culture, eliminating the nonpathogenic mycoplasmas and allowing MG to be isolated in pure culture. Mixtures of Mycoplasma synoviae (MS) and MG could not be separated in this assay. However, removal of nicotinamide adenine dinucleotide and cysteine hydrochloride during serial passage in Frey broth medium successfully eliminated growth of MS.

Profiling of cellular immune responses to Mycoplasma pulmonis infection in C57BL/6 and DBA/2 mice

“…Mycoplasmosis in humans accounts for 20 to 40% of all cases of pneumonia patients in the United States (53) and causes macrolide resistance problems (12,37). In livestock, mycoplasma respiratory infections also cause a huge problem and make a significant economic loss in many countries (1,2,27). In addition, many kinds of animals can be infected with mycoplasmas and receive the severe impact from the infection.…”

Impairment in the Isolation of Mycoplasma synoviae in Mixed Infection with Mycoplasma gallinaceum in Laying Hens

“…These findings underscore the importance of employing molecular methods such as PCR and sequencing for the identification of Mycoplasma spp. However, isolation still constitutes a crucial diagnostic method, as obtaining pure cultures is necessary for strain characterization during outbreaks (Boettger & Dohms, 2006). In this study, difficulties were encountered in obtaining pure MS cultures due to the rapid growth of Mgc.…”

Prevalence, diagnosis and treatment of mycoplasmosis in game birds

“…One strain of MG was isolated from pheasants which had a unique PGMA gene sequence containing a repetition of 12 nucleotides, and which was different from other MG strains isolated in Slovenia. MG was isolated by removing nicotinamide adenine dinucleotide (NAD) and cysteine hydrochloride from modified Frey's broth during the serial passage technique which eliminated the growth of MS (Boettger and Dohmsa, 2006). Bencina et al (2003) documented that the pathogenicity of strain ULB 972, which was isolated from the sinus of a pheasant, was very high for chicken embryos, because the entire embryo died within nine days.…”