Twelve-week-old indigenous chickens, either immune-suppressed using dexamethasone (IS) or non-immune-suppressed (NIS), were challenged with a low virulent strain, Pasteurella multocida strain NCTC 10322T, and developed clinical signs and pathological lesions typical of chronic fowl cholera. NIS birds demonstrated much more severe signs of fowl cholera than IS birds. With few exceptions, signs recorded in IS and NIS birds were of the same types, but significantly milder in the IS birds, indicating that immune suppression does not change the course of infection but rather the severity of signs in fowl cholera. P. multocida signals by fluorescent in situ hybridization (FISH) were observed between 1 h and 14 days in the lungs, trachea, air sacs, liver, spleen, bursa of Fabricius and caecal tonsils, while signals from other organs mostly were observed after 24 h. More organs had FISH signals in NIS birds than in IS birds and at higher frequency per organ. Many organs were positive by FISH even 14 days post infection, and it is suggested that these organs may be likely places for long-term carriage of P. multocida following infection. The present study has demonstrated the spread of P. multocida in different tissues in chickens and distribution of lesions associated with chronic fowl cholera, and pointed to a decrease of pathology in IS birds. Since dexamethasone mostly affects heterophils, the study suggests that these cells play a role in the development of lesions associated with chronic fowl cholera in chickens.

Flocks under study are located in the suburbs of Nairobi province and Machakos district. They belonged to smallholder farmers. Twenty seven clutches of eggs given to indigenous chickens to seat on, and 10 clutches of eggs given to ducks to seat on were investigated for six months. The number of eggs in each clutch ranged from 6 to 19 with an average of12 eggs. Duck eggs had a hatchability of 82.3% and fertility of 89.5% while chicken eggs had a hatchability of 66.2% and fertility of 82.8%. Staphylococcus spp, Streptococcus spp., Enterococcus spp., Escherichia coli, Proteus spp., and other aerobic bacteria were commonly isolated from un-hatched eggs, dead embryos, dead chicks, and ducklings. These were comparable with bacterial isolates recovered from cloacal and pharyngeo-tracheal swabs taken from adult birds from these farms and cultured on blood and McConkey Agar base. The main causes of chick and duckling mortalities were yolk sac infections, colibacillosis, and nutritional deficiencies. Other causes of mortality encountered were ectoparasites {fleas (Echidnophaga gallinacea) and lice (Menopon gallinae)}; and predators like kites, hawks, mongoose, dogs, wild and domestic cats. Kenya Veterinarian Vol. 31 (1) 2007: pp. 6-13

One hundred and twenty three indigenous chickens and 24 ducks reared under free range scavenging system were examined for the carrier status of Pasteurella multocida. Both the oropharynyngeal and cloacal swab samples were examined for the presence of the organisms by means of mouse passage and inoculation into blood agar. Of these, 53 chickens and 24 ducks were from different smallholder farms in Nairobi, and Machakos districts, 41 chickens were from various slaughterhouses in Nairobi, while 29 were market chickens obtained from various market centers in Nairobi. The traded (market and slaughter) chickens all originated from rural districts in various parts of the country. From the 123 chickens examined, Pasteurella multocida subspecies were isolated only from four birds. The isolates were recovered from the traded chickens only. Pasteurella organisms were not from any of the 24 ducks. On the basis of biochemical characterization, the organisms were differentiated as P. multocida multocida (1/4), P. multocida septica (1/4) and P. multocida gallicida (2/4). This study suggests that healthy traded poultry could be carriers of Pasteurella multocida. It describes the first report of Pasteurella multocida isolation from indigenous birds in Kenya. Kenya Veterinarian Vol. 31 (1) 2007: pp. 1-5

Pasteurella multocida causes fowl cholera, a highly contagious and severe disease in chickens and water fowls. The disease is not well described in less intensive production systems, including scavenging family poultry production in developing countries. P. multocida was isolated from 25.9% of healthy-looking ducks and 6.2% of chickens from free-range family poultry farms and at slaughter slabs at market. On experimental infection with 1.2 to 2.0x10(8) organisms of the P. multocida type strain (NCTC 10322(T)), 12-week-old chickens expressed fowl cholera clinical signs significantly more times (372 signs) than those of 4-week-old, 8-week-old and 16-week-old chickens (173, 272 and 187 signs) and more signs were severe. In family ducks the 8-week-old birds expressed clinical signs significantly more times (188 signs) than those of the other age groups (117, 80, and 83 signs, respectively) and severe signs were more frequent. P. multocida transmitted from seeder birds (n=12) to sentinel birds (n=30), which developed clinical signs, and in some cases lesions of fowl cholera allowed bacterial re-isolation, whether infected ducks served as seeders for chickens or chickens served as seeder for ducks. This study has documented the occurrence of P. multocida among healthy-appearing family poultry in a tropical setting, and demonstrated that age susceptibility is highest in 12-week-old family chickens and 8-week-old family ducks when challenged with a low-virulent strain of P. multocida. It has further demonstrated that cross-transmission of fowl cholera may happen between family ducks and chickens, and vice versa.

Two experiments were performed to study cross infections from chickens to ducks and vice versa. For each experiment the source birds (chickens or ducks) were infected with Pasteurella multocida strain 10322 T . The infected birds were then mixed with sentinel indigenous ducks or chickens, respectively, six hours after inoculation. To monitor cross transmission, oropharyngeal and cloacal swabs were taken from the sentinel birds daily, for culture on blood agar and other media, for two weeks. The cultured bacterial isolates were characterized for P. multocida through biochemical and other tests. For chickens to duck transmission study a few ducks (40%) picked the bacteria on the first day, number of infected birds increasing with time and the birds had high infection rate (60%) by day 14 post-infection. In the duck to chicken transmission study, most chickens (80%) were infected by the first day and maintained infection up to the twelfth day (60%) but appeared to clear the infection thereafter. These results showed that it was possible to transmit P. multocida from indigenous chickens to ducks and vice versa. The duck may be a better carrier of P. multocida under scavenging system than chickens. This contact cross transmission may be playing a role in the maintenance of the bacterium at the village level. The Kenya Veterinarian Vol. 29 2005: pp. 104-106

A total of one hundred and seventy one indigenous birds from smallholder farms and those traded in market centers in Nairobi were examined for the presence of Pasteurella multocida . Of these, 135 were farmed and 36 were market birds. They comprised of 117 indigenous chickens and 54 ducks. Three hundred and forty two oropharyngeal and cloacal swabs were collected from them and cultured onto blood agar and other media. The recovered isolates were characterized using colonial morphology, biochemical and other tests. Twenty three P. multocida isolates were recovered: 11/135 (8%) from farm and 12/36 (33%) from the market birds. Majority of the P. multocida isolates were Pasteurella multocida gallicida 11/23 (48%), followed by Pasteurella multocida multocida 7/23 (30%) and Pasteurella multocida septica 5/23 (22%). Pasteurella multocida gallicida isolates were encountered more in the market birds, while Pasteurella multocida multocida isolates were more in farm birds. Ducks had more isolates than chickens. The concentration of the birds at market areas appeared to favor the maintenance of P. multocida in the cages, crates and pens. Market birds may, therefore, play a major role in the spreading of P. multocida. The Kenya Veterinarian Vol. 29 2005: pp. 45-47

A total of forty-eight indigenous birds were intratracheally infected with Pasteurella multocida , paired and sacrificed at specified times. Seven organs from each of the four pairs were swabbed for culture and tissues taken for FISH test to detect the presence of the bacterium in these birds. Oropharyngeal and cloacal swabs were collected, for culture method and bacteria characterized by biochemical tests. While for FISH test, tissues were processed for histology after fixation in formalin for 24 hours and later preserved in 70% alcohol before in situ hybridization test. At any sacrificial time between 1hour and 14 days post inoculation P. multocida FISH signals were observed in 47 to 75% while the bacterium was isolated on culture in 7 to 50% of the organs of the indigenous birds. During the same period four (lung, trachea/oropharynx, liver and spleen) organs on FISH test and one (trachea/oropharynx) on culture were throughout positive for P. multocida . The large intestine/cloaca and pruning gland showed P. multocida FISH signals at various times but were negative for the bacterium on culture. Both tests were positive for P. multocida immediately after inoculation. FISH signals were found in a decreasing manner in the lung, trachea/oropharynx, liver, spleen, caecal tonsils, large intestine/cloaca, and pruning gland. On culture, the bacteria were found in a decreasing manner in the trachea/oropharynx, lung, spleen, liver and caecal tonsils. Most cultured isolates were made between 1 - 24 hours, few and intermittent ones thereafter, and none at all after the 10th day post infection. These results show that FISH test is more sensitive than the culture method for detection of P. multocida in tissues of infected birds. The Kenya Veterinarian Vol. 29 2005: pp. 53-56

BACKGROUND:Resistance of bacteria to antibiotics and disinfectants has been reported widely in the world. Listeria monocytogenes is no exception, although normally it tends to be variably sensitive to many antibiotics and disinfectants.OBJECTIVES:To assess the susceptibility of Listeria isolates recovered from indigenous chickens to commonly used antimicrobials.DESIGN:Nine Listeria isolates recovered from village chickens were tested for sensitivity to commonly used antibiotics and disinfectants and compared with Listeria monocytogenes type strains (L028 and DGH), Staphylococcus aureus NCTC 6571 and Escherichia coli ATCC 25922.SUBJECTS:Nine Listeria isolates.INTERVENTIONS:None.MAIN OUTCOME MEASURES:Susceptibility to eight antibiotics and seven disinfectants.RESULTS:The nine Listeria isolates were sensitive to gentamycin (100%), kanamycin (88.9%), tetracycline (77.8%), cotrimoxazole (66.7%), chloramphenicol (66.7%) and resistant to ampicillin, augmentin and cefuroxime. There was no difference between the antibiotic sensitivity to the various Listeria isolates and Listeria monocytogenes type strains (P > 0.05). The isolates were sensitive to disinfectants; A (100%), B (88.9%), D (77.8%), E (77.8%) but resistant to, CF, and G. There was significant difference between the resistance of Listeria isolates to the various disinfectants at the varied dilutions and the resistance at the recommended user--dilution (P < 0.00293).CONCLUSION:This study has shown that some of the Listeria isolates were resistant to most common antimicrobial agents except gentamycin and disinfectant A. Hence the need to consider this resistance pattern for effective treatment and control of listeriosis.

BACKGROUND:Listeria organisms are documented to be zoonotic; one of the sources of infection is the domestic fowl where it could occur as in apparent infection. The carriage of Listeria monocytogenes and other Listeria in indigenous birds has not been documented in Kenya.OBJECTIVE:To establish whether healthy looking indigenous chickens and ducks could be carriers of Listeria monocytogenes and other Listeria species.DESIGN:Field survey of indigenous chickens and ducks in three districts of Kenya.SETTING:Embakasi and Dagoreti divisions in Nairobi district; Athi river division in Machakos district; and Ngong division in Kajiado district, in Kenya.SUBJECTS:One hundred and thirty six indigenous chickens and 39 ducks reared under free range scavenging system in Nairobi, Machakos and Kajiado districts, in Kenya, were sampled.METHODS:In surveying the birds, the cloacal and pharyngeal swabs were taken from each bird separately using sterile cotton--tipped applicator swabs. The swabs in saline were transported in a coolbox to the laboratory for bacterial isolation and characterization.INTERVENTIONS:None (only compared farmed and the traded birds).MAIN OUTCOME MEASURES:Isolation of Listeria species and pathogenicity of Listeria isolates.RESULTS:Two Listeria monocytogenes and seven other Listeria species were recovered from the oropharyngeal swab samples of farm and market chickens but none from respective cloacal swabs. No Listeria was recovered from either oropharyngeal or cloacal swabs of farmed duck and slaughter chickens. Traded chickens yielded more Listeria isolates as compared to farmed chickens.CONCLUSION:This study shows that indigenous chickens in Kenya are carriers of Listeria monocytogenes and other Listeria species.

SUMMARYFifty-eight sera, from 29 chickens originating from two layer flocks known to be naturally infected withSalmonella enteritidisphage type (PT) 4, were examined for antibodies toS. enteritidis. Using the techniques of immunoblotting and ELISA, antibodies to the lipopolysaccharide (LPS) ofS. enteritidiswere detected in 43 of 58 sera. Antibodies were of the IgG class and bound to the S. enteritidis LPS antigen 0=12. Bacterial agglutination reactions using whole-cell preparations ofS. enteritidisandS. pullorum, correlated with anti-LPS antibody reactions as detected by immunoblotting and ELISA. A rapid means of screening chicken sera for antibodies to the LPS ofS. enteritidisas an indicator of infection is discussed.