Detection of Mycoplasma mycoides subsp. mycoides SC in bronchoalveolar lavage fluids of cows based on a TaqMan real-time PCR discriminating wild type strains from an lppQ− mutant vaccine strain used for DIVA-strategies

Abstract

Contagious bovine pleuropneumonia (CBPP) is the most serious cattle disease in Africa, caused by Mycoplasma mycoides subsp. mycoides small-colony type (SC). CBPP control strategies currently rely on vaccination with a vaccine based on live attenuated strains of the organism. Recently, an lppQ− mutant of the existing vaccine strain T1/44 has been developed (Janis et al., 2008). This T1lppQ− mutant strain is devoid of lipoprotein LppQ, a potential virulence attribute of M. mycoides subsp. mycoides SC. It is designated as a potential live DIVA (Differentiating Infected from Vaccinated Animals) vaccine strain allowing both serological and etiological differentiation. The present paper reports on the validation of a control strategy for CBPP in cattle, whereby a TaqMan real-time PCR based on the lppQ gene has been developed for the direct detection of M. mycoides subsp. mycoides SC in ex vivo bronchoalveolar lavage fluids of cows and for the discrimination of wild type strains from the lppQ− mutant vaccine strain.

An abattoir survey of contagious bovine pleuropneumonia lesions in slaughtered cattle in selected districts in Northern Tanzania

“…The estimated prevalence of 0.91% is slightly higher than findings of 0.01% in Nigeria [16] , however lower than the prevalence of 3.60% reported in Zambia [11] . Although the overall prevalence of CBBP was low, stratifications of prevalence by location and age category reveals that Karatu abattoir and animals aged [6][7][8][9][10][11][12][13][14][15][16][17][18] months to have recorded significantly high number of CBBP infected cattle than any other abattoirs and other age categories. The reason for high prevalence rate might be difficult to explain, however, detailed tracing of source of cattle indicate majority to originate from Matala (33.3%), Karatu (26.9%) and Mbulu (23.3%) areas which are thought to be CBPP endemic areas.…”

“…CBPP is characterized by the presence of sero-fibrinous interlobular oedema and hepatization giving a marbled appearance to the lung in acute to sub-acute cases and capsulated lesions (sequestra) in the lungs of some chronically infected cattle. The causative agent of CBPP is Mycoplasma mycoides subspecies mycoides small colony variant [5][6][7][8] . Affected animals have difficulty in breathing due to damage to the lungs; they loose condition and a proportion of them die.…”

Isothermal loop-mediated amplification (lamp) for diagnosis of contagious bovine pleuro-pneumonia

“…mycoides in extracted and often pre-cultured clinical samples (Gorton et al [24]; Schnee et al [16]; Vilei and Frey [17]). Whilst these are broadly accepted as the most specific and sensitive method and as reference tests in control and surveillance programs, they depend on an elaborate and expensive laboratory infrastructure; sophisticated equipment and personnel with advanced molecular diagnostic knowledge hence, are not applicable to field conditions where CBPP is endemic and where on-site diagnosis is vital to provide confirmation of disease.…”

“…During the last two decades, several conventional and real-time PCR methods (qPCR) for rapid diagnosis of CBPP and early outbreak warning have been developed (Bashirrudin et al [12]; Fitzmaurice et al [13]; Lorenzon et al [14]; Miserez et al [15]; Schnee et al [16]; Vilei and Frey [17]). Although such methods are specific and sensitive they depend on a laboratory infrastructure with sophisticated equipment and highly trained personnel.…”

Mycoplasma Mycoides Subsp. Mycoides Small Colony Variant and Mycoplasma Agalactiae Antibodies in Ruminants in Poland

“…Separated lung areas including inflammation and necrosis called "sequestrum" are found during the chronic stage of the infection (5,14). The control of MmmSC infections in Africa is based on animal vaccination using attenuated preparations (T1/44) and antibiotic treatment, but there are known many adverse reactions following immunoprophylaxis in the form of inflammatory skin damage, a short period of postvaccinal immunity or "cold chain dependence" (15,26). In the countries outside the African continent, the eradication of CBPP is possible due to the continuous monitoring of the animals and immediate eradication.…”