Investigation into gyneco-pathological disorders and identification of associated bacteria from the genital organs of cows in Dinajpur , Bangladesh

The present study was aimed to investigate the gynaeco-pathological disorders by post-mortem and histopathological examination, and to identify the associated bacteria. A total of 310 genital tracts of cows were collected from slaughter house of Dinajpur Sadar Upazilla during April 2009 to March 2010. Among the 310 samples, 31.29% (n=97/310) were affected with endrometritis. Similarly, 8.37% (n=26/310) cystic ovary, 6.77% (n=21/310) ovary hyperplasia, 4.84% (n=15/310) pyometra, 4.84% (n=15/310) parovarian cyst, 4.52% (n=14/310) hydrometra, 4.84% (n=15/310) ovary hypoplasia, 3.55%(n=11/310) ovaro-bursal adhesion, 1.29% (n=4/310) vaginal cyst and 0.66% (n=2/310)) hemorrhagic uterine horn were detected by postmortem examination, the cases were reconfirmed by histopathological studies. Uterine fluid (n=50) samples were collected, and were subjected for conventional bacteriological culture and biochemical analysis. Escherichia coli and Salmonella sp. could be identified from 30% (n=15/50) and 8% (n=4/50) samples, respectively. In conclusion, various pathological disorders in the female reproductive system of cows are prevalent, that may cause reduction of calf production.


INTRODUCTION
Livestock is an integral part of agriculture, and cattle provides important source of animal protein.Nowadays, most of the people in Bangladesh rears crossbred (local breed x foreign breed) cows for both milk and meat purposes.Sometimes the cross breed, local breed and foreign breed cows become infertile due to defective breeding program, inadequate knowledge of rearing system, and faulty ration formulation.Inadequate nutrition is the major cause of ovarian atrophy and subsequent anestrus and bacterial infection.According to Hossain et al. (1986) and Farooq (2000), gyneco-pathological disorders and found mostly in cross breed animals as compared to local cows.Infertility disorder in cows of Bangladesh is commonly seen because of poor nourishment, and using of low quality semen.
Following calving, the uterus of cow may become infected due to presence of infectious or non-specific microorganisms.Several bacterial, protozoan, viral and mycoplasmal infections are common in postpartum period.The most common and economically important bacteria for uterine infection are Actinomyces spp., Escherichia coli, Fusobacterium spp., Pasteurella spp., Pseudomonas spp., and Staphylococcus spp.(Erin et al., 2005).
Clinical endometritis is associated with delayed uterine involution and poor fertility.Bacterial pathogens are the potential cause when cows fail to conceive on one or more cycles in the same season.Nibret et al. (2013) isolated and identified S. pyogenes, E. coli and Streptococcus spp. as most frequently associated bacteria for fertility problem.Sulake et al. (2013) isolated and identified microflora species at different parts of the female genital tract (cervix, body of uterus, horns of uterus and oviducts) of ewes and indicated that there were different types of bacteria distributed throughout genital system as E. coli (37.83%),Salmonella (21.62%),Klebsiella (10.81%),Staphlococcus aureus (6.75%), Strptococcus spp.(6.75%), Proteus (6.75%), Micrococcus (5.4%) and finally others such as S. epidermid and Pseudomonus spp.(4.05%).Rahman et al. (1993) carried out a study on the incidence of reproductive disorders with 2280 cows and heifers in six Artificial Insemination (AI) pocket areas namely Hazirhat (Rangpur), Puthia (Rajshahi), Avoynagar (Jessore), Comilla, Manikganj and Moshurikhola (savar) during the period from July 1990 to June 1991.However, to the best of our knowledge, there is no report on the study of reproductive health problem in Dinajpur area of Bangladesh.Therefore, the present study was designed to investigate the gynecopathological disorders of cows and identification of the associated bacteria with genital organs of cows in Dinajpur, Bangladesh.

MATERIALS AND METHODS
Experimental area and animals: Mostly slaughtered animals in slaughter house in Dinajpur Sadar Upazilla were used for collection of samples.The animals aged between 6-8 years.Most of the slaughtered animals were of ill health.Their weight varied from 70-100 kg.

Sample collection:
A total of 310 cattle were examined and female genital tract samples such as uterus, vagina, cervix and ovary were collected from the different abattoirs houses of Dinajpur Sadar Upazilla, Bangladesh, and the samples were transferred to the Laboratory at the Department of Microbiology, and the Department of Pathology and Parasitology of Hajee Mohammad Danesh Science and Technology (HSTU) for necropsy, histo-pathological examination, and isolation and identification of the associated bacteria.

Post-mortem examination:
The gross examinations of the female reproductive tract followed by post-mortem examinations of all the samples were performed.All the reproductive tracts were examined carefully following the method of Mc Enttee (1983).The ovaries were examined for their functional activity as per the method described by Ahmed (1989).
Histo-pathological examination: During necropsy, various organs having gross lesions were collected, and were fixed in 10% buffered neutral formalin for histopathological studies.The formalin fixed tissue samples were then processed and stained as per standard method (Luna, 1968).
Isolation and identification of bacteria: Culture media used for isolation and purification of bacteria included: EMB agar, MacConkey agar, SS agar and nutrient agar (Oxoid, England).Inoculated media were incubated aerobically at 37ºC for 24 h.The bacteria were then identified by studying their morphology, Gram staining characters, and biochemical tests.

Biochemical test:
The bacterial isolates were identified by standard biochemical tests such as MIU test (Motility, indol and Urease test), TSI (triple sugar iron), Voges Proskauer (VP) test, as per the procedure of Forbes et al. (2007).
In this study, massive infiltration of lymphocytes, macrophages, monocytes and plasma cells in the endometrial mucosa, stroma and utetine glands was found (Figure 2).On the other hand, massive infiltration of neutrophils was found in the cases of pyometra which was supported by Rahman et al. (2002), Farooq (2000) and Manda et al. (2007).According to Kotowski (2001), the pathological changes more commonly found in the uterus as compared to those of ovaries.

CONCLUSION
Various pathological disorders in the female reproductive system may affect the reproduction performance.Further, it may be pointed out that various pathological disorders in female reproductive system are increasing menacingly along with introduction of cross breeding program through artificial insemination.The problem may be aggravated due to inadequate veterinary coverage and gynecological knowledge, which needs more attention.

Table 3 :
Isolation and identification microorganism from female genital tracts (n=50) of cattle.