Spatial epidemiological approaches to inform leptospirosis surveillance and control: A systematic review and critical appraisal of methods

Leptospirosis is a global zoonotic disease that the transmission is driven by complex geographical and temporal variation in demographics, animal hosts and socioecological factors. This results in complex challenges for the identification of high‐risk areas. Spatial and temporal epidemiological tools could be used to support leptospirosis control programs, but the adequacy of its application has not been evaluated. We searched literature in six databases including PubMed, Web of Science, EMBASE, Scopus, SciELO and Zoological Record to systematically review and critically assess the use of spatial and temporal analytical tools for leptospirosis and to provide general framework for its application in future studies. We reviewed 115 articles published between 1930 and October 2018 from 41 different countries. Of these, 65 (56.52%) articles were on human leptospirosis, 39 (33.91%) on animal leptospirosis and 11 (9.5%) used data from both human and animal leptospirosis. Spatial analytical (n = 106) tools were used to describe the distribution of incidence/prevalence at various geographical scales (96.5%) and to explored spatial patterns to detect clustering and hot spots (33%). A total of 51 studies modelled the relationships of various variables on the risk of human (n = 31), animal (n = 17) and both human and animal infection (n = 3). Among those modelling studies, few studies had generated spatially structured models and predictive maps of human (n = 2/31) and animal leptospirosis (n = 1/17). In addition, nine studies applied time‐series analytical tools to predict leptospirosis incidence. Spatial and temporal analytical tools have been greatly utilized to improve our understanding on leptospirosis epidemiology. Yet the quality of the epidemiological data, the selection of covariates and spatial analytical techniques should be carefully considered in future studies to improve usefulness of evidence as tools to support leptospirosis control. A general framework for the application of spatial analytical tools for leptospirosis was proposed.     

Microbiological quality of organic chicken meat during refrigerated storage in air and modified atmospheres

ABSTRACT

1. The aim of this study was to assess the incidence of pathogens and the development of spoilage microflora in organic chicken meat originating from a small poultry slaughterhouse and stored for 14 days at 2°C aerobically (control) or in one of two modified atmosphere packaging systems (MAP1: 80% O₂, 20% CO₂ and MAP2: 70% N₂, 30% CO₂).

2. Campylobacter jejuni survived well during storage; and was found on the skin in 95% of samples (262/276).

3. In general, both the skin and meat samples showed a good initial microbiological quality with total viable counts of less than 3 log cfu/g in meat and approximately 5 log cfu/g on skin.

4. No difference was found between breast and thigh samples during the experiment.

5. Shelf life was limited mainly by the development of mesophilic and psychrotrophic microflora on skin which were found at 7-day storage for the control and MAP1 and 10 days for MAP2.     

Efficacy of using previously used controlled internal drug release (CIDR) insert on the reproductive performance,hormone profiles and economic measures of sheep

This study was conducted using 120 multiparous Awassi ewes during the breeding season to compare the effects of using previously used controlled internal drug release (CIDR) on the hormone profiles, reproductive performance and economic measures of ewes. Ewes were randomized to receive one of five previously used CIDR (previously used for 6, 12, 18, 24 or 30 days) or the new CIDR as a control for 6 days (CIDR6, CIDR12, CIDR18, CIDR24, CIDR30, and CIDR0 [control], respectively). Blood samples were collected on four occasions, at the time of CIDR insertion, after 3 days of insertion, and at the time of withdrawal and insemination. Serum estradiol (E2) and progesterone (P4) concentrations were measured. Timed insemination was performed 48 hr post‐CIDR withdrawal. Pregnancy was diagnosed by ultrasonography 23 days after insemination and confirmed on day 35. The heat detection rate was significantly (p < 0.05) higher in the CIDR0 and CIDR6 groups than in the CIDR18 and CIDR30 groups. The total pregnancy rate and fecundity were significantly (p < 0.05) higher in the CIDR6 group than in other groups. P4 level was significantly (p < 0.05) higher in the CIDR0 group than in the CIDR30 group at the time of removal. At each time point, the E2 level was significantly (p < 0.05) higher in the CIDR6 group than at the other groups. The total variable cost, total cost, return and net profit were higher in the CIDR6 and CIDR0 groups than in the other groups. In conclusion, although previously used CIDRs are efficient at synchronizing oestrus in ewes, the duration of previously usage significantly affected the reproductive parameters and economic profit. CIDRs previously used for 6 days and new CIDRs provided the highest fertility and fecundity rates, besides return and net profit. Economically, it is not advisable to use CIDRs that previously used for 12 days or more.     

Comparison of four antibiotics with indigenous marine Bacillus spp. in controlling pathogenic bacteria from shrimp and Artemia

Use of antibiotics for the control of bacterial diseases in shrimp culture has caused several adverse impacts to the industry. This has resulted in the search for alternative environment friendly approaches to overcome bacterial infections. This study was conducted to investigate the use of beneficial bacteria as an alternative to antibiotics. Ten pathogenic bacterial species isolated from shrimp, Penaeus monodon, and Artemia cysts were tested for susceptibility to indigenous marine Bacillus subtilis AB65, Bacillus pumilus AB58, Bacillus licheniformis AB69 and compared with oxytetracycline, chloramphenicol, gentamicin and bacitracin, which are common antibiotics used in Asian aquaculture. The Bacillus spp. were isolated from the local marine environment for bioremediation use in shrimp hatcheries and were proven to reduce total ammonium nitrogen. The pathogenic bacterial isolates were 90% susceptible to B. subtilis AB65, 70% susceptible to B. pumilus AB58 and B. licheniformis AB69 and 100% susceptible to oxytetracycline, chloramphenicol and gentamicin but only 40% to bacitracin. Two representative isolates of the vibrio group, Vibrio alginolyticus VaM11 and Vibrio parahaemolyticus VpM1, when tested for competitive exclusion by a common broth method using the marine Bacillus spp., showed decreased viable counts from 10(8) to 10(2) cfu mL(-1). The results suggest that the action of the marine bacteria appears to be significant in protecting the host shrimp against pathogenic bacteria. In addition to the alternative use of antibiotics, the selected marine bacteria had additional bioremediation properties of reducing ammonia.     

Pathological changes,distribution and detection of Brucella melitensis in foetuses of experimentally-infected does

BackgroundBrucellosis of goats is caused by Brucella melitensis. It is a re-emerging zoonotic disease in many countries due to transmission from domestic animals and wildlife such as ibex, deer and wild buffaloes.ObjectiveTo describe the pathological changes, identification and distribution of B. melitensis in foetuses of experimentally infected does.MethodsTwelve female goats of approximately 90 days pregnant were divided into 4 groups. Group 1 was exposed intra-conjunctival to 100 µL of sterile PBS while goats of Groups 2, 3 and 4 were similarly exposed to 100 µL of an inoculum containing 10⁹ CFU/mL of live B. melitensis. Goats of these groups were killed at 15, 30 and 60 days post-inoculation, respectively. Foetal fluid and tissues were collected for bacterial identification (using direct bacterial culture, PCR and immuno-peroxidase staining) and histopathological examination.ResultsBilateral intra-conjunctival exposure of pregnant does resulted in in-utero infection of the foetuses. All full-term foetuses of group 4 were either aborted or stillborn, showing petechiations of the skin or absence of hair coat with subcutaneous oedema. The internal organs showed most severe lesions. Immune-peroxidase staining revealed antigen distribution in all organs that became most extensive in group 4. Brucella melitensis was successfully isolated from the stomach content, foetal fluid and various other organs.ConclusionVertical transmission of caprine brucellosis was evident causing mild to moderate lesions in different organs. The samples of choice for isolation and identification of B. melitensis are stomach content as well as liver and spleen tissue.     

Leveling-index based variable rate seeding technique for paddy

Precision Agriculture - Poor land leveling of paddy fields leads to irrigation problems which affect crop establishment and ultimately yield. One way to manage this is to vary the seeding rate...     

First record of Oomyzus scaposus (Hymenoptera: Eulophidae), as a parasitoid of Coccinella septempunctata (Coleoptera: Coccinellidae) in Pakistan

Coccinella septempunctata L. (Coleoptera: Coccinellidae) is a natural enemy of several important pests. This biocontrol agent is also a host for different parasitoids. Little is known about the parasitoid complex of C. septempunctata in Pakistan. The authors identified Oomyzus scaposus (Thomson, 1878) (Hymenoptera: Eulophidae) as a larval-pupal parasitoid of C. septempunctata in the district of Sargodha, Punjab, Pakistan. Out of 36 C. septempunctata pupae collected, 58.3% were parasitized by O. scaposus. This study documents the first record of O. scaposus parasitizing C. septempunctata in Pakistan.     

Micropropagation of mature Calabrian pine (Pinus brutia Ten.) from fascicular buds

Dormant meristems of fascicles explanted from 10-year-old, field-grown trees of Pinus brutia Ten. were cultured in vitro. Browning of cultured fascicles was reduced by including 150 mg l(-1) sodium diethyldithiocarbamate (SDD) in a cytokinin-containing medium. The stage of development of fascicles when placed in culture affected both shoot-bud production and the degree of browning. Only fascicles at an advanced stage of development had a high rate of shoot-bud production. Fascicles cultured for 6 weeks in initiation medium containing 150 mg l(-1) SDD and then for 4 weeks in initiation medium containing 1 mg l(-1) insoluble polyvinylpolypyrrolidone showed the highest rate (23%) of shoot-bud development and the lowest rate (15%) of browning. Elongation of activated shoot buds was considerably enhanced by reducing the concentration of cytokinin in the culture medium. Only shoots >/= 20 mm in height were capable of producing further crops of buds and shoots. When treated with a combination of auxin and cytokinin, only 16% of the elongated shoots produced roots.     

Replacing bacitracin methylene disalicylate by crushed Nigella sativa seeds in broiler rations and its effects on growth, blood constituents and immunity

The effect of using crushed Nigella sativa seeds (NSS) as a natural growth promoter instead of the antibiotic growth promoter bacitracin methylene disalicylate (BMD) in broiler rations that contain one of two types of anticoccidials (either lasalocid Na or 3-nitro) on growth performance, blood constituents and some selected antibody titers was studied. An experiment was conducted on five dietary groups with two different growth promoter's supplementation from one to 42 days of age. The statistical findings of this experiment prove that replacing BMD by crushed NSS significantly improve growth performance. The serum levels of cholesterol, triglyceride were significantly decreased, while, high density lipoprotein (HDL) was significantly increased. Concerning the findings that pertain to immunity, antibody titer against Newcastle and infectious bursal diseases were significantly improved by replacing BMD by crushed NSS, but no significant effects were noticed in antibody titer against infectious bronchitis. In conclusion, from the results of the current study it could be speculated that crushed NSS could be of value to replace BMD in broiler diets. Further studies must be performed to detect the proper level of NSS before field application.     

Effects of Lactobacillus cultures on growth performance,abdominal fat deposition,serum lipids and weight of organs of broiler chickens

1. The effects of a mixture of 12 Lactobacillus strains (LC) on the growth performance, abdominal fat deposition, serum lipids and weight of organs of broiler chickens were studied from 1 to 42 d of age. 2. One hundred and thirty-six 1-d-old male broiler chicks were assigned at random to two dietary treatments: a basal diet (control), and a basal diet with 0.1% LC. 3. The supplementation of LC in broiler diets improved the body weight gain and feed conversion rate from 1 to 42 d of age and was effective in reducing abdominal fat deposition but only after 28 d of age. 4. The LC diets reduced serum total cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides in broilers from 21 to 42 d of age. However, there was no significant difference in serum high density lipoprotein (HDL) cholesterol between control and LC-fed broilers. There was also no significant difference in the weights of organs of control and LC-fed broilers. 5. The results indicated that the mixture of 12 Lactobacillus strains have a hypolipidaemic effect on broilers.