Incidence of Avian Mycoplasmosis in the region of Batna , Eastern Algeria

Avian mycoplasmosis is infectious and contagious disease which affects chicken and turkey as well as many other species with many economics losses. The absence of data on avian mycoplasmosis in Algeria and the importance of the poultry breeding in Batna encouraged us to undertake the prevalence of the most pathogenic mycoplasmas in broiler and layer chickens in this area, Mycoplasma gallisepticum (MG). 143 Mycoplasmas were isolate from 237 samples, at a rate of 60.33%. MG was isolate at a rate of 21.67% (2.09% in layer hens and 19.58% in broiler chickens). The serological screening using of breedings showed a sensitivity of 83.10%. This study shows that mycoplasmosis and in particular MG infection, represent a serious problem in chickens in Algeria in the absence of hygiene conditions and vaccination especially.


Material and Methods
Avian mycoplasmosis is caused by several Our study was conducted between October 2008 pathogenic mycoplasmas of which Mycoplasma and September 2010 in 23 flocks divided as follows: gallisepticum (MG) and Mycoplasma synoviae (MS) laying hens (n = 11), broiler chickens (n = 13).These are the most important.MG causes chronic respiratory farms were divided into 10 districts of the wilaya of disease of domestic poultry especially in the Batna.Birds collected during this investigation were management stresses and/or other respiratory apparently healthy or with respiratory lesions of lung, pathogens.Disease is characterized by coryza air sacs, or trachea.The number of poultry per farm conjunctivitis sneezing and sinusitis particularly in varied between 3000 and 5000.Broilers were reared in turkeys.It can result in loss of production and the soil over a straw litters.Laying hens were caged.It downgrading of meat-type birds and loss of egg should be noted that the density standards, ventilation production.MS may cause respiratory disease and hygiene were exceptionally observed.synovitis or may result in a silent infection.MG and Sampling: 148 of blood samples were taken as MS strains vary in infectivity and virulence and follows: infections may sometimes be unapparent (Bradbury, 69 blood samples from laying hens 2001; Ley, 2003;OIE, 2008).
79 blood samples from broiler-chickens.The frequent occurrence of unspecified clinical After coagulation during 2 hours at room signs of respiratory disease among poultry flocks in temperature, the serum is centrifuged at 1500 tr/min Batna region and the lack of data on the role of for 15 min and inactivated at 56°C for 30 min.then the mycoplasmas in these diseases had encouraged us to serum is diluted to 1/5 to reduce non specific and undertake this investigation.
cross-reactions between MG and MS.The aim of this study was to evaluate the All serum are put in sterile aliquots and prevalence of MG infection in broilers and laying hens maintained at 4°C until use within the following 48 in the region of Batna (Eastern Algeria) using the rapid hours.slide agglutination test and the isolation and Bacteriology: For the bacteriological diagnostic, 237 identification method.Among 237 analyzed samples samples of tracheas, lungs and air sacs were taken MG was isolate at a rate of 21.67% of which 2.09% in from recently dead birds or those dead frozen until use laying hens and 19.58%in broilers.(Evans et al., 2009).
Culture medium of mycoplasmas: Liquid and solid is carried out after a color changing had occurred in the Frey`s medium was used for the isolation of liquid medium.If no color changing has occurred in mycoplasmas (Frey et al., 1968) representing a rate of infection of 83.10% showing the 25µl of serum and 25µl of antigen are put on a strong spread of MG.However, the rate of infection glass slide previously washed, rinsed and dried.The was slightly higher in broiler-chickens (84.81%) than antigen and serum are mixed at room temperature of in laying hens (81.15%) (Table I). the reaction is carried out according to Stanley et al., The highest prevalence (100%) of MG infection 2001.
was found in the present study in El Madher, Ain Mycoplasma isolation: The reference strain of MG yagout and Boumia (TableII) Seasonal variation of used is MG ATTC 15302 produced in rabbit and kindly prevalence of MG infection was observed in the supplied by the LNPA, France.
present study.The prevalence was higher (91.13%) in About 0.5 g of tissues (tracheas, lungs and air winter season and lower (73.91%) in summer season sacs) are cut in small pieces and ground in a sand bath (Table III).containing 5 ml of mycoplasma medium.
According to the age, the highest prevalence of 0.2 ml of this suspension is inoculated in Frey`s MG infection was 86.95% in chicks whereas lowest liquid medium.When a color change is observed in the prevalence was 82.35% in adult (Table IV).liquid medium, another inoculation of a fresh liquid Bacteriology: 143 mycoplasmas strains were medium is perform.isolated from 237 organ samples representing a Later on an inoculation of Frey`s solid medium positivity rate of 60.33%.III).Indeed, rate of infection of 90% has been rapid serum agglutination (RSA) may lack specificity noted during winter, compared to that of 73.91% and/or sensitivity.Therefore, its use is strongly recomobtained during summer.These results are in mended for monitoring flocks rather than for testing accordance with those of Sikder et al. ( 2005 The effect of age on the occurrence of laboratory conditions by using fresh sera.The latter mycoplasmal infection is revealed in the study with a had been decomplemented in order to ovoid cross rate of infection of 69.9% and 48.7% in adult and reactions between MG and MS and diluted to 1/5.The young birds respectively (Table II).evaluation of the RSA test was validated using known In the present study, MG has been isolated at a positive and negative control sera.In our study the size rate of 21.67% (Table V).This rate is higher than to of tested samples is similar to that reported by several those found by Helail, 1998 (11.89%).others ranging between 10 and 30 birds (Boucetta et The results of mycoplasma isolation from al., 1997; Kermorgant, 1998 andSabir, 2003).
different organs showed that air sacs are the main site This study has revealed a very high prevalence of multiplication of this microorganism from dead of Mycoplasma gallisepticum infection either in birds (90%).Similar result was also obtained by laying hens or in broiler-chickens in Batna region.Our Helail, 1998 (36.29%) and Shaker, 2005 (92%).Lungs results are higher than those of similar studies.
are the second site of isolation (71.42%) followed by For instance, Thai et al. (2009) I).This value is greatly The discordance observed between serology and higher than results obtained by Baruta et ), Sarkar et individual birds.For this reason we had tried to al. (2005) and Hossain et al. (2010).establish the test sensitivity and specificity under our . It consist of PPLO the liquid medium a subculture is done on a solid broth base (2.1%) and PPLO agar (1%) (Difco medium because it is well known that mycoplasmas Laboratories).are very slow-growing microorganisms (Kleven, The media base was enriched with 15% horse 2008).If Mycoplasma growth is noted on solid serum; 1%of glucose; and 10% yeast extract.medium, agar blocks containing colonies are Contamination of media was prevented by adding 1% transferred in tubes of liquid medium for thallium acetate and 0.5% penicillin G potassium.mycoplasmas cloning (Stipkovits et al., 1975).Serology: The detection of antibodies against MG Positive cultures were characterized by Dienes was achieved by the rapid slide agglutination staining, biochemical and growth inhibition tests method.MG antigen was kindly supplied by Dr using MG antiserum produced in rabbit kindly Bouchardon.AG, the laboratoire national de supplied by Dr Bouchardon.A.G. pathologie aviaire (LNPA) of Ploufragan France.The Results serum quality was checked using a negative SPF avian serum, a positive serum against Mycoplasma Serology: Among 148 tested sera, 123 were positive gallisepticum Mg15.

Table - 2. Seroprevalence of Mycoplasma gallisepticum according to the study area Study area Number of samples Number of positive sera Rate of SPA %
as follows: 3 in laying hens and (2005) found a rate of infection by MG of about 90%.28 in broiler-chickens representing 2.09% and 19.58%A similar study conducted in Bangladesh showed that respectively (Table I). the rate of infection varies from 45.1% to 66.5% It should be stated that all flocks either laying (Hossain et al., 2010; Barua et al., 2006).These hens or broiler-chickens harbor MG. results are higher than those in the present study.This study has revealed a sharp influence of Discussion season on the incidence of avian infection by MG The serological test in this study, for instance the (Table