Impact of herd mobility on brucellosis seroprevalence and spread risk resulting from cross-border transhumance.

BACKGROUND: Cross-border livestock mobility through transhumance is mainly practiced in West African countries for seasonal access to resources and market. Cross-border herds are involved in the dynamic of transboundary animal diseases among them brucellosis taken as model. Brucellosis is a zoonotic disease causing abortion. OBJECTIVES: This study explores the seroprevalence of brucellosis according to mobility and infection spread between Mali and Côte d'Ivoire in the context of seasonal cross-border transhumance. METHODS: From February to April 2021, a transversal serological survey of brucellosis was conducted on 521 cattle from 111 transhumant herds and 283 cattle from 59 sedentary herds, all from Mali. RESULTS: The global individual seroprevalence for Brucella spp. in transhumant and sedentary cattle from Mali was 8.2% (95% CI = 6.0-10.5). At herd level, seroprevalence was 21.2% with a significant variation between transhumant (11.7%) and sedentary (39.0%) herds. For herds in transhumance, cattle seropositivity was associated with a previous infection suspected by herdsmen odds ratio (OR = 4.4; 95% CI = 1.1-18.1) and unknown abortion aetiology (OR = 4.3; 95% CI = 1.0-17.3). The departure region (coming from Sikasso) and previous brucellosis infection or unexplained abortion could be used to predict Brucella infection in transhumant herds with a probability of around 60%. The risk of brucellosis introduction in host regions was high despite the individual animal seroprevalence of 3.6% and a low sale rate in transhumant cattle. CONCLUSIONS: The findings suggest that testing transhumant during border control and survey of cattle markets and sales could improve risk control of the spread of disease at regional scale.

Serological evidence and factors associated with Crimean-Congo haemorrhagic fever in sheep in Burkina Faso.

BACKGROUND: Crimean-Congo haemorrhagic fever (CCHF) is caused by an orthonairovirus transmitted by bites from infected ticks or by direct contact with blood or tissues of infected ticks, viraemic patients or viraemic livestock. OBJECTIVE: It was implemented to access the seropositivity and associated factors with CCHF in sheep in two provinces in Burkina Faso. METHODS: Three hundred and sixty-four sheep sera have been taken from 73 herds in four municipalities and two provinces. The double-antigen sandwich ELISA test was used to test for antibodies against CCHF virus (CCHFV). Data have also been collected using questionnaire to assess factors associated with CCHF seropositivity. RESULTS: Fifty-four (54 out to 364 sheep were seropositive given an overall seropositivity of 14.8% (95% confidence interval [CI]: 10.9%-19.8%) with an adjusted seropositivity of 13.1%. The study showed that 15.6% (95% CI: 10.2-21.0) and 14.1% (95% CI: 9.2-19.1) of sheep in the provinces of Mouhoun and Kénédougou, respectively, had antibodies against CCHFV. The highest seropositivity was found in Dédougou municipality (24.4%). The study showed that sheep from the municipalities of Dédougou (AOR = 8.4; 95% CI: 2.2-31.8), N'dorola (AOR = 14.7; 95% CI: 3.8-56.8), Sindou (AOR = 4.9; 95% CI: 1.2-20.7), sheep aged between 27 and 36 months (AOR = 6.4; 95% CI: 2.3-17.3) and sheep with ticks (AOR = 24.8; 95% CI: 7.7-80.1) were more likely to be seropositive to CCHF. CONCLUSIONS: The study revealed that sheep in Burkina Faso experienced contacts with CCHFV and suggests the importance of implementing control action in the country.

Using causal loop analysis to explore pathways for zoonosis control in low-income setting: The case of dog rabies vaccination in Burkina Faso.

Dog vaccination is an effective pathway to control rabies if a minimum of 70% dog vaccination coverage is achieved. For more than six decades, dog vaccination has been adopted as part of the rabies control measures in Burkina Faso. However, the required vaccination coverage in canine population remains challenging and rabies endemic. This study describes the use of systems thinking to explore the dynamics arising from dog vaccination complexity and explain the possibles causes of low vaccination coverage in the dog population. In-depth interviews were conducted in three administrative regions and included various stakeholders. A thematic analysis was performed to analyze the obtained narratives. Subsequently, causal loop diagrams (CLDs) were developed, depicting the causes of low dog vaccination coverage. The CLDs were composed of reinforcing loops and balancing loops, visualizing how different variables including social, economic, technical, political and organizational factors that affect the implementation of rabies vaccination in the country are causally interrelated. Overall, the results revealed the importance of community awareness raising, strengthening the vaccination workforce, enhanced governance and leadership in the dynamics of dog vaccination. The study calls for wide consideration of all drivers and factors that may affect dog vaccination coverage, for the development of any rabies control strategy or vaccination program. Beyond the dog vaccination problem, the methods and findings from this study could be applied to other critical rabies-related questions such as postexposure prophylaxis, epidemiological surveillance, dog population management, laboratory diagnosis, and the One Health collaboration issues, to understand and improve rabies control.

Antibiotic resistance of Escherichia coli and Salmonella spp. strains isolated from healthy poultry farms in the districts of Abidjan and Agnibilékrou (Côte d'Ivoire).

BACKGROUND AND AIM: Antimicrobial resistance (AMR) is a serious challenge to animal and human health worldwide. Therefore, this study aims to determine levels and patterns of AMR of Escherichia coli and Salmonella spp. strains isolated from poultry farms in Côte d'Ivoire. MATERIALS AND METHODS: A cross-sectional study was conducted in two districts of Côte d'Ivoire with high poultry production: Abidjan and Agnibilékrou. A total of 231 fecal samples were collected in 124 poultry farms in both districts. Enterobacteria were isolated and tested for susceptibility to 14 antimicrobial agents using the disk-diffusion method. RESULTS: A total of 212 E. coli and 36 Salmonella strains were isolated. In Abidjan, 139 collected samples generated 101 E. coli and 23 Salmonella strains, whereas in Agnibilékrou, 92 collected samples generated 111 E. coli and 13 Salmonella strains. Variable resistance levels were recorded for the antibiotics tested. The resistance prevalence of E. coli and Salmonella, respectively, was high: Doxycycline (98%/94%), sulfonamide (84%/86%), trimethoprim-sulfamethoxazole (80%/41%), and streptomycin (71%/52%). Average resistance rates were recorded for flumequine (38%/66%), ampicillin (49%/33%), amoxicillin (25%/44%), colistin (26%/2%), chloramphenicol (21%/2%), and gentamicin (4%/47%). The antibiotics least affected by resistance were cefuroxime (4%/5%), ceftriaxone (2%/0.00%), and nitrofurantoin (1%/0.00%). CONCLUSION: In this study, it was observed that resistance to important antibiotics is emerging in poultry production in Côte d'Ivoire. Policies promoting the rational use of antibiotics should be implemented to manage antibiotic resistance in animal production.

Factors Influencing the Transborder Transmission of Brucellosis in Cattle Between Côte d'Ivoire and Mali: Evidence From Literature and Current Key Stakeholders.

Brucellosis is one of the main zoonoses affecting ruminants. Cattle and small ruminants are involved in transhumance and trade between Côte d'Ivoire and Mali. The endemic nature of the disease in both countries, connected through transhumance, poses unique challenges and requires more information to facilitate disease surveillance and the development of integrated control strategies. This study aimed to assess the main factors influencing the historical and current transborder transmission of brucellosis between Côte d'Ivoire and Mali. A literature review was conducted and data collection was performed through a participatory, transdisciplinary process by holding focus group discussions and interviews with key stakeholders. Cattle breeders, herdsmen, professionals of animal and human health, border control agents and experts took part. The data was analyzed to generate essential new knowledge for transborder brucellosis transmission factors and control strategies. From the literature, the seroprevalence of brucellosis in both countries varied from 11% (1987) to 20% (2013) and 15% (1972-1973) to 5% (2012-2014) in Mali and Côte d'Ivoire, respectively. The reduction of seroprevalence in Côte d'Ivoire was the result of the annual vaccination campaigns which lowered it from 28% (1978) to 14% (1984) after an increase due to livestock policy implemented in 1976. The meta-analysis and interviews jointly showed that the cross-border mobility was associated with the livestock development policy in Côte d'Ivoire as well as the ECOWAS act on the free movement of people and goods. This act supported the seasonal transhumance of livestock for access to pasture land in southern humid zones in Côte d'Ivoire. The seasonal mobility for grazing and trade was the main risk factor for the spread of brucellosis between pastoral zones of both countries. The existing legal health framework and border control mechanism do not achieve transborder surveillance to control brucellosis. Existing sanitary regulations should be adapted at regional scale to integrate a joint surveillance of high priority zoonotic diseases like brucellosis at border controls.

"We never boil our milk, it will cause sore udders and mastitis in our cows"- consumption practices, knowledge and milk safety awareness in Senegal.

BACKGROUND: Milk is a nutrient-rich food that makes an important contribution to diets in several Low and Middle Income Countries such as Senegal. Milk can also harbour several pathogenic microorganisms. As in other low and middle income countries, the dairy industry in Senegal is growing, with an expansion of farms to meet rapidly growing demand in the cities. However, most of the production still happens in the informal sector, and little is known about consumption of milk and milk products, or knowledge, awareness and practices of actors in informal dairy supply chains. METHODS: We conducted structured focus group discussions with dairy farmers and milk processors in three selected regions (Dakar, Thies and Fatick) in Senegal to investigate the consumption practices, awareness of milk borne hazards, and practices relevant to the risk of milk contamination to gain a deeper understanding of drivers of milk-borne diseases. Data on the consumption of milk and milk products were also collected using a closed questionnaire. RESULTS: Results indicate that milk is an important part of the diet in the study regionsand raw milk consumption is very common. The most common milk product consumed was fermented milk. Awareness of milk borne hazards was limited. Several farmers and processors reported risky practices, despite being aware of better practices, due to cultural beliefs. In households, children, pregnant women and older people were prioritised when milk and milk products were distributed. Dairy farmers and milk processors were more concerned with the lack of food for animals, low production and seasonality of production than the safety of the milk and milk products. CONCLUSIONS: Lack of awareness of milk borne infections and some traditional practices put milk and milk product consumers in the study area at high risk of milk borne diseases.. Prioritising certain sub population at households (Pregnant women and children) makes then vulnerable to milk-borne hazards. It will be challenging to change the risky practices as they are motivated by cultural beliefs hence the best strategy to promote milk safety will be to encourage the boiling of milk by consumers.

Prevalence of colistin resistance and mcr-1/mcr-2 genes in extended-spectrum ß-lactamase/AmpC-producing Escherichia coli isolated from chickens in Canada, Senegal and Vietnam.

OBJECTIVES: This study investigated the prevalence of Escherichia coli (E. coli) colistin resistance and mcr-1 and mcr-2 genes among extended-spectrum ß-lactamase (ESBL)/AmpC-producing E. coli isolates recovered from chicken feces in Canada (Quebec), Senegal and Vietnam, and evaluated the susceptibility pattern of the colistin-resistant E. coli isolates to other clinically relevant antimicrobials. METHODS: A total of 327 potential ESBL/AmpC-producing E. coli isolates from chicken farms in Canada (Quebec), Senegal and Vietnam were analysed for colistin susceptibility by broth microdilution method and for the presence of mcr (1-2) genes by PCR. The pmrA and pmrB genes of colistin-resistant E. coli isolates, in the absence of mcr (1-2) genes, were sequenced. Antimicrobial resistance phenotypes of colistin-resistant E. coli isolates were determined by disk diffusion. RESULTS: None of the 108 potential ESBL/AmpC-producing E. coli isolates from seven farms in Canada were colistin-resistant or possessed mcr-1 or mcr-2 gene. A low prevalence of 2.2% of colistin resistance was observed in 93 Senegalese isolates from the 15 sampled farms, although neither mcr-1 nor mcr-2 gene was found. A prevalence of 8.7% of colistin resistance was observed among 126 Vietnamese isolates from two of the four sampled farms. The mcr-1 gene was detected in 85% of the 13 phenotypically colistin-resistant isolates. Moreover, all colistin-resistant isolates presented a multidrug-resistant phenotype. CONCLUSIONS: The co-existence of the mcr-1 and ESBL/AmpC genes and the very high level of multiple drug resistance in all colistin-resistant E. coli isolates obtained from sampled chicken farms in Vietnam is a major concern.

Antimicrobial Resistance and Potential Pathogenicity of Escherichia coli Isolates from Healthy Broilers in Québec, Canada.

Antimicrobial resistance (AMR) is a global health issue, particularly when it affects critically important antimicrobials such as third-generation cephalosporins (3GC). The objective of this study was to characterize Escherichia coli isolates from healthy chickens in Québec in farms where ceftiofur has been administered to chickens in ovo over a long period with regard to their AMR, multidrug resistance (MDR), potential virulence, clonality, and possession of plasmids of the incompatibility groups carrying extended-spectrum beta-lactamases (ESBLs)/AmpC genes. More than 62% of indicator isolates were MDR with resistance observed for each of the nine classes of antimicrobials tested by disk diffusion. 3GC resistance was encoded by the blaCMY-2 gene (26.7% in indicator isolates), whereas blaCTX-M was only detected in isolates selected after supplementation with ceftriaxone (3 blaCTX-M-1 isolates). Examination of blaCMY-2-positive isolates by pulsed-field gel electrophoresis showed clustering of isolates originating from different floors of the livestock building within farms. The blaCMY-2 gene was carried on replicon plasmids FIB, I1, K/B, and B/O, whereas blaCTX-M-1 gene was located on I1 as demonstrated by transformation experiments; some of these plasmids cotransferred nonsusceptibility against tetracycline or sulfonamides. In addition, six isolates, of which three were AmpC-producers, were defined as potential human extraintestinal pathogenic E. coli. In summary, this study showed that ESBLs/AmpC-producing E. coli isolates from apparently healthy chickens in Québec, Canada predominantly possess blaCMY-2 rather than blaCTX-M maybe because of the in ovo use of ceftiofur to prevent omphalitis and may be spread through clones or plasmids, and that some of these isolates could be capable of infecting humans.

Pathogenic potential and the role of clones and plasmids in beta-lactamase-producing E. coli from chicken faeces in Vietnam.

BACKGROUND: Antimicrobial resistance (AMR) in food-producing animals is a global public health issue. This study investigated AMR and virulence profiles of E. coli isolated from healthy chickens in Vietnam. E. coli were isolated from fecal samples collected in five chicken farms located in the provinces of Hoa Binh, Thai Nguyen and Bac Giang in the North of Vietnam. These isolates were examined by disk diffusion for their AMR, PCR for virulence and AMR genes, pulsed-field gel electrophoresis for relatedness between blaCMY-2/blaCTX-M-positive isolates, electroporation for transferability of blaCMY-2 or blaCTX-M genes and sequencing for mutations responsible for ciprofloxacin resistance. RESULTS: Up to 99% of indicator isolates were multidrug resistant. Resistance to third-generation cephalosporins (3GC) was encoded by both blaCTX-M and blaCMY-2 genes; blaCTX-M genes being of genotypes blaCTX-M-1, - 14, - 15, - 17, - 57 and - 87, whereas ciprofloxacin resistance was due to mutations in the gyrA and parC genes. Some isolates originating from farms located in different provinces of Vietnam were found to be closely related, suggesting they may have been disseminated from a same source of contamination. Plasmids may also have played a role in the diffusion of 3GC-resistance as the blaCMY-2 gene was located on plasmids A/C and I1, and the blaCTX-M gene variants were carried by I1, FIB, R and HI1. Plasmids carrying the blaCMY-2/blaCTX-M genes also co-transferred resistance to other antimicrobials. In addition, isolates potentially capable of infecting humans, of which some produced blaCMY-2/blaCTX-M, were identified in this study. CONCLUSIONS: Both clones and plasmids could be involved in the dissemination of 3GC-resistant E. coli within and between chicken farms in Vietnam. These results demonstrate the necessity to monitor AMR and control antimicrobial use in poultry in Vietnam.

Prevalence of antimicrobial resistance and potential pathogenicity, and possible spread of third generation cephalosporin resistance, in Escherichia coli isolated from healthy chicken farms in the region of Dakar, Senegal.

Escherichia coli is a normal inhabitant of the intestinal microbiota of chickens, a small proportion of which may be avian pathogenic E. coli (APEC) or potential extraintestinal pathogenic E. coli (ExPEC), capable of causing disease in humans. These E. coli may also be resistant to antimicrobials of critical importance in human or veterinary health. This study aims to 1) determine the prevalence of antimicrobial resistance (AMR) and resistance genes, multidrug resistance (MDR), chromosomal mechanisms of quinolone-resistance and virulence profiles of E. coli isolated from healthy chicken farms in the region of Dakar, Senegal, 2) investigate the spread of third-generation cephalosporins (3GC) resistance in E. coli isolated from healthy chicken farms with respect to virulence and resistance genes, serogroups, Pulsed-Field Gel Electrophoresis (PFGE), phylogenetic groups, plasmid types and transferability and 3) determine whether nonsusceptibility against 3GC on farms could be linked to risk factors. More than 68% of isolates from environmental faecal and drinking water samples, carcasses and carcass washes collected on 32 healthy chicken farms were multidrug resistant (MDR), resistance to antimicrobials critical in human health (3GC or ciprofloxacin) being found in all types of samples. Ciprofloxacin resistance was due to mutations in the gyrA and parC genes, 95% of tested farms harboring isolates carrying three mutations, in gyrA (Ser83Ile and Asp87Asn) and parC (Ser80Ile). Nine of the 32 farms (28.1%) demonstrated the presence of one or more 3GC-nonsusceptible indicator isolates but none of the potential risk factors were significantly associated with this presence on farms. Following ceftriaxone enrichment, presumptive extended-spectrum beta-lactamase/AmpC-beta-lactamase (ESBL/AmpC)-producer isolates were found in 17 of the 32 farms. 3GC resistance was mediated by blaCMY-2 or blaCTX-M genes, blaCTX-M being of genotypes blaCTX-M-1, blaCTX-M-8 and for the first time in chickens in Senegal, the genotype blaCTX-M-15. Clonally related ESBL/AmpC-producer isolates were found on different farms. In addition, blaCTX-M genes were identified on replicon plasmids I1 and K/B and blaCMY-2 on K/B, I1 and B/O. These plasmids were found in isolates of different clusters. In addition, 18 isolates, some of which were ESBL/AmpC-producers, were defined as potential human ExPEC. In conclusion, E. coli isolates potentially pathogenic for humans and demonstrating MDR, with resistance expressed against antimicrobials of critical importance in human health were found in healthy chickens in Senegal. Our results suggest that both clonal spreading and horizontal gene transfer play a role in the spread of 3GC-resistance and that chickens in Senegal could be a reservoir for AMR and ExPEC for humans. These results highlight the importance of raising awareness about compliance with biosecurity measures and prudent use of antimicrobials.

Serological Prevalence of Contagious Bovine Pleuropneumonia in Niger in 2017.

Contagious bovine pleuropneumonia (CBPP) is a highly contagious disease of cattle caused by Mycoplasma mycoides subsp. mycoides Biotype Small Colony (MmmSC). The disease currently occurs in most of sub-Saharan Africa and where it is endemic and a major constraint for improving pastoral productivity. Following the persistence of this scourge, and in order to control this disease, a serological survey was conducted to determine the prevalence of CBPP in Niger. In fact, 1,590 sera were collected following a stratified sampling plan based on the risk factor of dissemination of CBPP. The analysis were performed at the Central Livestock Laboratory using the c-Elisa test. The results obtained show a wide distribution of the disease with an overall prevalence of 4.15% at individual level. The highest prevalences were recorded in the South-East regions [Zinder (7.5%), Diffa (7.5%)] and the West part [Tahoua (6.9%)]. The prevalence at the commune level was about 36.55%, which was relatively high. The prevalence at strata level was 36.55% (95% PI 0.2428-0.4882). The expected prevalences did not match those found. The results of this serological survey are considered the reference situation (T0) of CBPP in Niger with the PRAPS project, and allowed to the country to redefine control policies for better control of the disease at national and sub-regional level.

Molecular Characterization of Escherichia coli Isolated from Chickens with Colibacillosis in Senegal.

Avian pathogenic Escherichia coli (APEC), a subset of extraintestinal pathogenic E. coli (ExPEC), are the etiologic agent of avian colibacillosis, one of the main causes of economic losses in the poultry industry. The aim of this study was to characterize E. coli isolated from diseased chickens in Senegal to elucidate their virulence potential and antimicrobial resistance (AMR). A total of 58 isolates, each from a separate farm, were characterized for AMR, virulence, and AMR genes, phylogroup, serogroup, biofilm formation, and pulsed-field gel electrophoresis, and for two isolates, whole-genome sequencing (WGS). Fifty isolates (86.2%) were multidrug resistant. Many AMR genes were detected, including variants of blaCTX-M encoding resistance to third-generation cephalosporins (five isolates [8.6%]). Most fluoroquinolone-nonsusceptible isolates (21/26) were carriers of mutations in gyrA (Ser83Leu, Asp87Asn, and/or Asp87Tyr) and/or parC (Ser80Ile) genes. Forty-nine (84.5%) isolates exhibited at least one of the virulence markers of APEC, among which 23 (39.7%) were defined as potential virulent APEC. In addition, 10 isolates, of which 9 were defined as APEC, carried virulence profiles corresponding to ExPEC. Seven isolates, of which six were classified as ExPEC, belonged to phylo-serogroup F-O25, and following WGS of two of these isolates, were found to belong to the serotype O25:H1 and to the sequence type ST624. Some isolates classified as ExPEC, including F-O25, were found to strongly produce biofilm, suggesting their capability to persist for long time in the environment. F-O25-isolates, although found in different widely separated farms, formed a single cluster that included clones, suggesting that these isolates may have originated from a common source. Taken together, these results suggest that some E. coli involved in chicken colibacillosis in Senegal may pose a human health risk.

A 3-year long study of Staphylococcus aureus isolates from subclinical mastitis in three Azawak zebu herds at the Sahelian experimental farm of Toukounous, Niger.

Staphylococcus (S.) aureus is one of the most important pathogens causing bovine mastitis. The aim of the present work was to follow in three herds and during the 3 years the clonality of S. aureus isolated from California Mastitis Test (CMT)-positive cows at the experimental station of Toukounous (Niger) by (i) comparing their pulsed field gel electrophoresis (PFGE) fingerprints, (ii) identifying their virulotypes by PCR amplification and (iii) assessing the production of capsule and the formation of biofilm. The 88 S. aureus isolates belonged to 14 different pulsotypes, 3 of them being predominant: A (30 %), D (27 %), B (15 %). A and B pulsotypes had the highest profile similarity coefficient (94 %), while others had similarity coefficients under 60 %. Seventy-five S. aureus isolates were further studied for their virulotypes, capsular antigens and biofilm production. Most surface factor-, leukocidin- and haemolysin-, but not the enterotoxin-encoding genes were detected in the majority (>75 %) of the isolates and were evenly distributed between the A, B and D pulsotype isolates. The majority of the 72 S. aureus positive with the cap5H or cap8H PCR produced the CP5 (82 %) or the CP8 (88 %) capsular antigen, respectively. Biofilm production by the 57 icaA-positive isolates was strong for 8 isolates, moderate for 31 isolates but weak for 18 isolates, implying that the icaA gene may not be expressed in vitro by one third of the positive isolates. Similar to other studies, those results confirm that a restricted number of S. aureus clones circulate within the three herds at Toukounous and that their specific virulence-associated properties must still be further studied.

Microbiological quality of milk from small processing units in Senegal.

Consumption of milk and dairy products has increased significantly in Senegal in the last decade, and a large part of the local production comes from small processing units spread all over the country. We collected 85 bulk-tank milk samples from 68 smallholder dairy farms throughout the territory. Microbiological quality of milk samples was analyzed according to the official standards. Further, raw milk and pasteurized milk were screened for Mycobacterium bovis, Coxiella burnetii, and anti-Brucella abortus antibodies. Ninety-three percent of pasteurized milk samples, 92% of raw milk samples, and 81% of sour milk samples failed to meet official standards. Pathogens detected in milk were C. burnetii (6/41, 15%), which seems to be endemic in Senegal, coagulase-positive staphylococci (18/70, 26%), and Salmonella Johannesburg in one sample. Further analysis of coagulase-positive staphylococci isolated from samples containing more than 10(4) colony-forming units per gram showed the presence of enterotoxigenic strains in 9 of the 10 samples. These results confirm the poor microbiological quality of milk produced by small units in Senegal, especially and surprisingly of pasteurized milk. This highlights the need to implement good hygiene practices, particularly in the postpasteurization process, and an effective monitoring throughout the production and delivery chain.

Antimicrobial resistance of Salmonella isolated from poultry carcasses in Dakar (Senegal)

This study was undertaken to estimate the antimicrobial resistance of Salmonella isolated from raw chicken. From November 2003 to April 2004 a total of 120 chicken carcasses were collected from 36 randomly selected sale points (supermarkets, traditional market, poultry slaughter house, flocks) in the urban and periurban zones of Dakar, Sénégal, and examined for the presence of Salmonella. Salmonella was isolated from 75 (62.5 percent) of the examined samples. Out of the 90 Salmonella isolates obtained, twenty one serotypes were identified, from which the most prevalent were S. Kentuchy 30 percent, S. Muenster (13.3 percent), S. Brancaster (8.8 percent), S. Enteritidis and S. Hadar (6.6 percent). All Salmonella isolates were tested for their susceptibility to 16 selected antimicrobial agents by the agar diffusion method. Seventy one (78.9 percent) isolates were resistant to one or more antimicrobials. Out of 71 resistant Salmonella isolates, 33 (46.5 percent) showed multiple resistance to five or more different antimicrobials. Resistance to ampicillin, trimethoprim, trimethoprim-sulphamethoxazole, tetracyclin and sulphonamides was the most frequent. We found 36 different patterns of multiresistant strains. The high level of antibiotic resistance of foodborne Salmonella isolates in the present study is an indication of indiscriminate and continuous use of subtherapeutic doses of antibiotics in animals. Furthermore, the results showed the possible significance of chicken meat as a source of multiple antimicrobial-resistant Salmonella for human infections and suggest the need for detailed epidemiological study.

O presente estudo foi realizado com o propósito de aviliar a resistência aos antibióticos dos sorovares da Salmonella isolados da carne de frango crua. De novembro de 2003 até abril de 2004, um total de 120 carcaças de frango foram compradas em 13 pontos de venda e 23 centros de criação de frangos. As Salmonella foram isoladas a partir de 75 (62,2 por cento) carcaças analisadas. Vinte e um (21) sorotipos diferentes foram identificados, sendo os mais freqüentes S. Kentucky (30 por cento), S. Muenster (13,3 por cento), S. Brancaster (8,8 por cento), S. Enteritidis e S. Hadar (6,6 por cento). Todos os sorovares de salmonela foram examinados a fim de determinar a resistência à 16 antibióticos. Setenta e quatro (79,6 por cento) foram resistentes à um antibiotico ou mais, das quais 33 (45,6 por cento) mostraram resistência múltipla a cinco antibióticos (ampicilina, trimetoprim, trimetoprim-sulfametoxazol, tetraciclina e sulfonamidas). Foram encontrados 36 perfis diferentes de resistência múltipla. O nível elevado de resistência dos isolados de Salmonella encontrados na carne do presente estudo, é um indicador do uso indevido e contínuo de doses subterapêuticas de antibióticos nos animais. Por outro lado, os resultados do estudo demonstram a importância da carne de frango como fonte potencial de sorovares de Salmonella multiresistentes transmissíveis ao homem e sugerem um estudo epidemiólogico detalhado.

Domestic animals as carriers of Bordetella species in Senegal.

Despite intense efforts to maintain a high level of vaccine coverage against human whooping cough, rural senegalese areas are still endemic for Bordetella pertussis. One explanation being the potential existence of animal reservoirs, the objective of this work was to precise the carriage by domestic animals of bacteria belonging to the genus Bordetella in Senegal. Bacteriological samples (swabs and aspirates) were obtained from various domestic animals living in different parts of the country. No B. pertussis nor B. parapertussis were isolated. However, for the first time to our knowledge, B. bronchiseptica was identified from small ruminants located in Africa. The positive animals were two goats and two sheep from Dakar slaughterhouse together with a goat living in a rural compound. The fact that it was identified in goats and sheep underlines the potential zoonotic of that bacterial species in countries where small ruminants are of economical and cultural relevance.