The intracellular bacteria of the proliferative enteropathies: a comparison of in vitro and in vivo infection

The intracellular bacteria from naturally occurring porcine proliferative enteropathy were cultured in an in vitro cell culture systea, the norphology of the bacteria, the pathogenicity of the organism in vivo, in hamsters, and the morphological events of infection in both cultured cells and hamsters were investigated.Bacteria purified from intestinal lesions of the disease were cultured in a rat enterocyte, IEC-18 cell line. Infection was enhanced by centrifugation of the bacteria onto the cell monolayer incubated at reduced oxygen tension in a aicroaerobic atmosphere. However, centrifugation was not necessary for infection to occur. Bacterial infection can be passaged and maintained several times.Morphological observations of the bacteria grown in cell culture pelleted by centrifugation revealed that the bacterium measure from 0.1 to 0.3pm in width and 0.7 to 2.0pm in length. The bacteria were pleomorphic with a wavy trilaminar outer membrane and an often indistinct cytoplasmic membrane generally clearly separated by a periplasmic space. The pleomorphic bacteria differed in the internal structure and in the electron density of their cytoplasm; some were electron-dense and some were electron-lucent. The internal structure of the former was amorphous and consisted of numerous granules, presumably bacterial ribosomes whereas the latter demonstrated a central reticulate appearance with less dense peripheral granules. Bacterial divisions were consistently seen in the electron-lucent form and were by transverse septation.IEC-18 cells were used as an in vitro model to study the cellular events of intestinal cell infection. Cells were artifically infected either by centrifugation or spontaneously. A method of bacterial attachment and entry into the host cell was observed in both methods of infection. In ccntrifuged infection, bacteria were seen attached by an electron-dense cap projection of the cell membrane. In contrast, bacteria were seen closely apposed to the cell membrane in noncentrifuged infection. However, in both cases, attachment of the bacteria was followed by entry into and escape from endocytic vacuoles free into the cytoplasm. Bacteria then multiplied to large numbers to fill the cytoplasm and were eventually released by extrusion from the host cell cytoplasm.The aetiology and pathogenesis of the disease in hamsters infected with the pig-derived bacteria was revealed. Hamsters developed marked hyperplasia of the crypt epithelial cells associated with numerous bacteria in the apical cytoplasm when dosed with the bacteria cultivated in cell culture. Cellular events of infection, morphologically similar to that observed in the in vitro model were evident.This study revealed that the intracellular bacteria from porcine proliferative enteritis can be cultured and passaged in rat enterocytes in vitro and suggest that the in vitro model is a relevant model of in vivo infection, in hamsters as both models showed similar stages in the pathogenesis of infection and proved that the porcine-derived intracellular bacteria grown in IEC-18 cells are pathogenic in hamsters

Bacteriology of vaccinated and non-vaccinated eye of cats.

Thirty cats were divided into two groups: group 1 (owner-kept cats) and group 2 (stray cats). Group 1 consisted of 11 cats in which the vaccination status was up to date whereas group 2 consisted of 19 cats in which the vaccination status was unknown. Conjunctival swabs were taken from these cats for bacteria isolation and identification. Giemsa staining of the swabs was also conducted to identify Chlamydophila sp. Two cats in group 1, one male and one female Persian which had bilateral watery discharge, were positive (18.18%) for bacteria in their eyes. The male Persian cat was positive for Enterobacter spp. and Moraxella nonliquefaciens bilaterally. However, in both eyes of the female Persian cat, only Enterobacter spp. was isolated. In group 2, 11 domestic short hair stray cats had only Staphylococcus intermedius in their eyes which did not show any ocular discharges. Three cats in this group had bilateral isolation and four had unilateral isolation of this bacteria. Of the 30 cats studied, the most predominant bacteria isolated was S. intermedius (36.67%) followed by Enterobacter spp. (6.6%) and M. nonliquefaciens (3.3%). None of the 30 cats studied showed the presence of Chlamydophila sp. in their eyes and there was no evidence of eye lesions in these cats. It is believed that the S. intermedius isolated was normal conjunctival flora of the eyes of these cats. Enterobacter spp. and M. nonliquefaciens could also be the normal flora of the Persian cats, since these bacteria were isolated from their eyes in the absence of lesions but with ocular discharge that may promote the growth of these microorganisms

Detection of heavy metal residues in the muscle and skin of Tilapia.

A study of detect the presence of heavy metals, which are Lead (Pb), Copper (Cu) and Zinc (Zn) in Tilapia cought from 3 waterways in Universiti Putra Malaysia, Serdang, Selangor was conducted. Water samples from the study sites were also sampled and analysed. These locations were in the academic areas of Universiti Putra Malaysia, Serdang campus near the agricultural and housing areas. Results showed that the mean concentration of Cu, in the water was 0.04 µg/mL and Pb and Zn were 0.03 µg/mL. The concentration of the elements tested was found to be lower than the recommended limits set by FAO/WHO but the concentration of Pb almost breached the limit of 0.05 µg/mL. The mean concentration of Pb in the fish muscles (0.64 µg/g) did not exceed the permissible limits set by FAO/WHO (1.5 µg/g) and the Malaysian Food Regulation (1.0 µg/g). The concentration of Cu in the fish muscle was much lower (2.13 µg/g) than the permissible limits set by the WHO (10.0 µg/g) and the Malaysian Food Regulation (30.0 µg/g). The highest element that had accumulated in the fish muscle was Zn (8.28 µg/g). However. The concentration of Zn did not exceed the permissible limits set by FAO/WHO (150.0 µg/g) and the Malaysian Food Regulation (100.0 µg/g). In the fish skin, the concentration of Cu and Pb were quite high. The concentration for Pb in the skin (6.77 µg/g) exceeded both the permissible limits set by FAO/WHO (1.5 µg/g) and the Malaysian Food Regulation (2.0 µg/g) while the concentration of Cu in the skin only exceeded the permissible limits set by FAO/WHO (10.0 µg/g). Among the three elements studied, Zn concentration was highest in the fish skin (45.8 µg/g). However, the Zn levels did not exceed the permissible limits of FAO/WHO and the Malaysian Food Regulation. Therefore, it can be concluded that the Tilapia caught from the waterways were not suitable for animal animal and human consumption because the concentration Pb in the fish skin was too high. Cooper was also found to be present in the skin at concentration that can pose health hazard. However, these fishes can be said to be safe to be consumed if the skin were to be removed

Ecology of Haemaphysalis wellingtoni in Red Junglefowl

The ecology of the parasitic stages of Haemaphysalis wellingtoni was studied in 30 Red Junglefowls in a farm in Jenderam Hulu, Sepang, Selangor, Malaysia. The free ranging Red Junglefowls are trapped using leg traps and individual bird was carefully examined for tick infestations. The ticks were collected from the neck, comb, and outer ear canal, counted and preserved in 70% ethanol. The identification of the tick species and their stages at each site was done through examination using a stereomicroscope and keys to tick identification. Tissue biopsies with ticks attached were also obtained to determine the pathology of tick-feeding sites. The comb tissues were processed with the standard histological technique and stained with hematoxylin and eosin to observe the cellular changes initiated by the ticks. Only one species of the tick was identified, which was Haemaphysalis wellingtoni. The mean of tick numbers in the outer ear canal was the highest (1.77± 0.193), followed by the dorsal aspect of the neck (1.32± 0.329) and the comb (0.72± 0.190). In this study, there are significant differences in stage of the ticks at different infestation sites suggesting that they have preferential site for different stages of their life-cycle. Generally, the mean count for tick stages (adult, nymph and larval) were almost similar on the dorsal part of neck and the outer ear canal. The mean numbers of nymph and larval stages in the neck and outer ear canal were similar, except for the adult stage which was 3.63 on neck and 3.33 in the outer ear canal. However, adult stage was absent on the comb while the mean of nymph stage was 0.16. The larval stage was lower in number in the comb (0.87) compared to the neck and outer ear canal (both 2.2). The cellular changes observed at tick feeding sites consisted of eosinophil and very high lymphocyte infiltrations which indicated chronic inflammation. The congestion, hyperkeratosis and detachment of the keratin layer were also observed at tick feeding sites

Primary transmissible venereal tumour in the nasal cavity of two dogs

Transmissible venereal tumour (TVT) is a common tumour affecting dogs especially strays. Usually, the external genitalia is most frequently affected. Although there are reports of extra-genitalia TVT (usually secondary), incidence in the nasal cavity as a primary tumour is extremely rare. This paper describes the presence of primary TVT in the nasal cavity of two dogs along with the postulated pathogenesis. It also warrants clinicians to consider this tumour as one of the differentials for prolonged nasal discharge and nasal neoplasm

Clinical response and pathological changes associated with Pasteurella multocida type B infection through oral route inoculation in mice

Haemorrhagic septicaemia (HS) is caused by Pasteurella multocida type B in Asia (P. multocida type B). It is an important cattle and buffalo disease in Malaysia as well as other Southeast Asian countries due to its nature of acute and highly fatal disease which have an economic impact on the affected countries. This study describes the clinical signs and histopathological changes in mice following oral route inoculation with P. multocida type B. In this study, sixteen mice were selected and divided into two groups of 8 mice each. Mice in group 2 were inoculated with 1.0 mL 109CFU/mL P. multocida type B orally while group 1 with PBS orally. The entire challenged group showed significant clinical signs (P<0.05) where ruffled fur, laboured breathing, less responsive and dullness together with eye discharge were observed. Six out of 8 mice died between 24 to 50 hours post-inoculation. Histopathological lesions observed include haemorrhage, congestion, degeneration and necrosis and infiltration by the inflammatory cells in the lungs, kidney, heart, liver and small intestine. The study showed that experimental P. multocida infection in mice caused oedema the lungs and infiltration of numerous Kupffer cells in the liver

The responses by gut-associated and bronchus-associated lymphoid tissues of buffalo calves following oral exposure to Pasteurella multocida B:2

This report describes the mucosal immune response in the gastro-intestinal and respiratory tracts of buffalo calves following oral exposure to live wild-type Pasteurella multocida B:2. Nine buffalo calves of approximately 8 months old were treated with intramuscular injections of dexamethasone for 3 consecutive days before they were divided into 3 groups. Calves of group 1 were exposed orally to 50 ml inoculums containing 109 colony forming units (CFU)/ml of live wild-type P. multocida B:2. Calves of group 2 were exposed intratrachea with 5ml of the same inocula while calves of group 3 were given 50ml of PBS orally. At the end of day 7 post-exposure, all surviving calves were killed and organs of gastrointestinal and respiratory tracts were processed for histology examination. The presence of lymphoid nodules, the size of the nodules and the number of lymphocytes were noted. Both oral and intra-trachea exposures elicited mucosal responses in both gastro-intestinal and respiratory tracts. Oral exposure stimulated significantly (p <0.05) superior mucosalresponse in the gastrointestinal tract, while intratracheal exposure stimulated significantly (p<0.05) superior mucosal response in the respiratory tract. Overall, oral exposure was ableto stimulate the distance mucosal sites such as the respiratory tract and provides potential use for oral administration of live vaccine against haemorrhagic septicaemia

Ultrastructural pathology of the upper respiratory tract of rabbits experimentally infected with Pasteurella multocida A:3

Twenty-four 8 to 9 week-old Pasteurella multocida-free rabbits were divided into three equal groups, the first group was pretreated with hydrocortisone and inoculated intranasally with pasteurella multocida serotype A:3. The second group was inoculated intranasally with P. multocida without hydrocortisone treatment. The third group was inoculated with phosphate buffered saline only and used as a control group. Pasteurella multocida was isolated from the nasal cavity of all infected rabbits in group 1 and 2 and from the trachea of seven rabbits in group 1 and five rabbits in group 2. This study was conducted to observe the ultrastructural changes of the upper respiratory tract of hydrocortisone treated and non-treated rabbits infected with P. multocida serotype A:3. The ultrastructural changes detected in infected rabbits were ciliary destruction and deciliation of the ciliated epithelial cells, cellular swelling, goblet cell hyperplasia and endothelial cell damage. Pasteurella multocida was observed attached to the degenerated cilia,microvilli and mucus. Pasteurella multocida infection was associated with inflammatory responses, which may have caused tissue damage. It is possible that hydrocortisone modulates the severity of infection as an immune suppressor and an inhibitor of goblet cell secretion

LOW LEVELS OF MICROVESSEL DENSITY AND IMMUNOHISTOCHEMICAL EXPRESSION OF VASCULAR ENDOTHELIAL GROWTH FACTOR IN CARCINOGEN-INDUCED DUCTAL MAMMARY GLAND CARCINOMA OF RATS SUPPLEMENTED WITH GARLIC

The present study was conducted to evaluate the anti-angiogenesis activity of diet containing 5% of garlic powder (G) on mammary gland carcinoma induced by N-methyl-N-nitorsourea (MNU) in female Sprague Dawley rats. A total of 24 female Sprague Dawley rats were randomly assigned in to three groups namely, control, MNU and MNU+G (n=8). MNU group rats received four consecutive subcutaneous (sc) injections of MNU at a dose of 60 mg/kg per injection and basal diet, MNU+G group rats received four consecutive sc injections of MNU at a dose of 60 mg/kg per injection and diet containing 5% of garlic powder, while control rats were injected with normal saline and fed with normal diet. All rats were euthanised at 24 weeks of experimental period. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) expressions were investigated through histopathology and immunohistochemistry methods. Results showed MNU induced ductal mammary gland carcinoma in rats of MNU and MNU+G groups. MVD scoring values showed significant (p&lt;0.05) higher score of MNU group compared to MNU+G and control groups. Overexpression of VEGF was observed significantly (p&lt;0.05) in MNU group compared to MNU+G and control groups. Administration of diet containing 5% of garlic powder to female Sprague Dawley rats minimised the development of ductal mammary gland carcinoma by inhibiting the angiogenesis activity.Â