Rats and leptospirosis, a unique tropical experience

Rats are the maintenance host for leptospirosis and are the source of the infection to humans and animals. To eradicate leptospirosis, then the maintenance hosts should be eliminated. This is not possible, particularly when it involved wildlife like rats. A good alternative then is to impose biological control on the rat population which is a safe and pragmatic approach. The environment is the indirect source of infection and in tropical countries; recreational areas are often the place foroutbreaks of leptospirosis. Claims that leptospires survive for months in the environment probably is not true. The “top up” or daily excretion of leptospires from the maintenance hosts particularly rats make it appears that the leptospires survived for months in the environment. The good news is that although there are many infected rats in the cities, there were hardly any reports of outbreaks of leptospirosis in urban areas. Outbreaks of leptospirosis tend to be in the countryside particularly in recreational areas, where infection is easily transmitted through the conjunctiva or mucous membrane of the upper respiratory or gastro-intestinal tract through water activities

A Serological And Bacteriological Study Of Leptospiral Infection In Domestic Animals In Peninsular Malaysia

A cross-sectional serological survey of domestic animals in Wes t Malaysia revealed that 2 5 . 5 percent of the animals examined had agglutinating antibodies to one or more antigens belonging to Leptospira interrogans . Significant prevalence of infection was observed in cattle ( 40 . 5 % ) , buffaloes ( 31 % ) and pigs ( 16% ) .The Sejroe and Pomona serogroups were the principal one s involved whilst infections to the other eight serogroups appeared insignificant and were indicative of sporadic infection . Majority of the large cattle and buffalo farms demonstrated high prevalences of leptospiral infection . Amongst cattle , the droughtmasters had the highest prevalence whilst the Kedah-Kelantan ( an indigenous breed ) had the lowest prevalence of leptospiral infection . Leptospiral infection in goats and sheep was shown to be sporadic . A bacteriological survey of cattle revealed 18.9 percent ( 42 /222 ) had leptospiral infection . Isolates were obtained from all herds except one . Six leptospiral serovars , namely , canicola, australis, javanica, ballum, pomona and hardjo were isolated for the first time in cattle in Malaysia . An isolate obtained from a bovine kidney proved to be a new serovar and was given the name.\ud unipertama . The small number of buffalo urine samples examined were all negative on culture

Efficacy of a commercial probiotic in protecting mice against Salmonella infection

It is believed that probiotics are able to inhibit pathogenic bacteria from colonizing the gastrointestinal tract and thereby prevent infection and even mortality. On this basis, this project was undertaken to examine the efficacy of a commercial probiotic in preventing infection in the mouse model. This probiotic is made up of 8 bacterial species from 3 genera. Forty 6-week old white ICR mice were used in this project. The mice were divided into 7 groups consisting of positive and negative controls, 2 preventive groups and 3 treatment groups. The infective inocula were made up of a Salmonella typhimurium isolate. All mice in the positive control and treatment groups were severely affected when inoculated with the Salmonella isolate. Eleven (73%) of the 15 mice in the treatment groups died from the Salmonella infection. Salmonella was recovered from the internal organs of the mice in the positive control group and the treatment groups. No Salmonella was isolated from the internal organs of the mice in the negative control and the preventive groups. This showed that the probiotic was not able to prevent serious infection if given during or after infection. When the probiotic was given earlier as a prophylaxis, it was able to prevent serious infection. In this project, it is seen that none of the mice from the preventive groups succumbed to the Salmonella infection. It was clearly shown that probiotics were able to prevent adverse infection if given earlier as a prophylaxis

Leptospiral infections in stray dogs in Malaysia

Leptospirosis is a zoonotic disease of worldwide importance. Besides rodents, dogs have also been implicated as a source of infection to humans. Samples of urine and blood from 142 stray dogs were examined for leptospirosis by serological tests and bacterial cultures. Of these, 83% (118/142) and 33% (471142) of the serum samples were positive by ELISA-IgM/IgG and the microscopic agglutination test (MAT) respectively. No leptospiral isolates were obtained on culture. Leptospira interrogans serovar pomona was found to be the most predominant serovar in the dogs with an infection rate of 68% at MAT titres of ~ 100. Urine and serum samples were randomly selected for detection and identification of leptospires by the polymerase chain reaction (PCR) and low-stringency PCR assay respectively. All seropositive samples selected were positive by PCR assay. One urine sample showed the presence of leptospires based on PCR assay

A review of the epidemiology and control of brucellosis in Malaysia

The presence of brucellosis in large ruminants and pigs in Malaysia was confirmed by the isolation of Brucella abortus in 1950 and Brucella suis in 1963, respectively. Subsequently, brucellosis was detected in humans (1980), dogs (1982) and sheep(1991). The National Programme for 'The Area-wise Eradiction of Bovine Brucellosis 'which came into effect in 1979 had reduced the prevalence of bovine brucellosis in Malaysia from 3.3% in 1979 to 0.23% in 1988. It was then envisaged that by 1995 bovine brucellosis in Malaysia had been eradicted. However, the prevalance of brucellosis in cattle was reported to be high (<2%) again (Anon,2005). In the state of Pahang, there was a surge in prevalence from 0.2% in 1996 to 13% in 1998 but was brought down to 1.8% in 2005 by stringent testing, culling and vaccination. The success of the eradiction programme in the later phase proved to be difficult due to the remote geographical distribution of the animals, the extensive farming system being practised and the education and social status of the farmers. In the later phase of the programme, it was difficult to detect infected animals in the herds as the prevalence of infection was very low. It therefore, became necessary to test every animal so as not to miss the few inapparent carrier animals. For this, the enzymelinked immunosorbent assay was a useful test and was included, in addition to the Rose Bengal plate test (RPBT), to complement fixation test (CFT) and the Milk Ring Test (MRT)in the screening and diagnosis of brucellosis. Bacterial culture and isolation of suspected cases of bovine brucellosis (abortion, retained placenta) were additional measures undertaken to detect animals

A low molecular weight lipopolysaccharide antigen preparation reactive to acute leptospirosis heterologous sera.

There is a need for identification of new infection markers against common Leptospira isolates in Malaysia. To achieve this goal, seven-day-old cultures of Leptospira interrogans serogroup Icterohemorrhagiae (L44) and Leptospira interrogans serogroup Javanica (L55) were used for antigen preparation by sequential extraction method using 40 mM Tris, 8M Urea and 2M thiourea. Immunoblot analysis of the antigens were performed using serum samples from 46 local patients with confirmed acute leptospirosis, 28 patients with other infections and 14 healthy controls. The patients serum samples used in this study contained heterologous antibody against a number of different Leptospira serovars. A strong IgM reactivity to a broad diffuse band of 10-15 kDa was observed. Combining results using L44 and L55 antigens showed sensitivity of 80.4% and specificity of 95.2% for detection of leptospirosis. Proteinase K and periodate treatment indicated that the band is likely to be lipopolysaccharide (LPS) in nature. This study showed that the 10-15 kDa antigen could potentially be useful for serodiagnosis of acute leptospirosis in Malaysia

Karakterizacija izolata leptospira postupkom otiska nasumce umnožene polimorfne DNA.

Random amplified polymorphic DNA (RAPD) fingerprinting was applied to characterize leptospiral strains. Two primers were used to generate individual RAPD fingerprints. The DNA fingerprints obtained were distinct and reproducible. The fingerprints obtained could be useful for distinguishing and characterizing the strains. Profiles obtained revealed genetic heterogeneity between strains belonging to one serovar. In conclusion, different DNA fingerprints were obtained which would allow characterization of the strains.Postupak otiska nasumce umnožene polimorfne DNA primijenjen je za karakterizaciju sojeva leptospira. Dvije početnice rabljene su za proizvodnju zasebnih otisaka umnožene polimorfne DNA. Dobiveni otisci DNA bili su međusobno različiti i reproducibilni te bi se mogli rabiti za razlikovanje i karakterizaciju sojeva. Njihovi profili pokazali su genetsku heterogenost među sojevima koji su pripadali jednom serovaru. Zaključno se može reći da su dobiveni različiti otisci DNA koji omogućuju karakterizaciju sojeva leptospira