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In 2021, amidst the COVID-19 pandemic and global food insecurity, the Nigerian poultry sector was exposed to the highly pathogenic avian influenza (HPAI) virus and its economic challenges. Between 2021 and 2022, HPAI caused 467 outbreaks reported in 31 of the 37 administrative regions in Nigeria. In this study, we characterized the genomes of 97 influenza A viruses of the subtypes H5N1, H5N2, and H5N8, which were identified in different agro-ecological zones and farms during the 2021–2022 epidemic. The phylogenetic analysis of the HA genes showed a widespread distribution of the H5Nx clade 2.3.4.4b and similarity with the HPAI H5Nx viruses that have been detected in Europe since late 2020. The topology of the phylogenetic trees indicated the occurrence of several independent introductions of the virus into the country, followed by a regional evolution of the virus that was most probably linked to its persistent circulation in West African territories. Additional evidence of the evolutionary potential of the HPAI viruses circulating in this region is the identification in this study of a putative H5N1/H9N2 reassortant virus in a mixed-species commercial poultry farm. Our data confirm Nigeria as a crucial hotspot for HPAI virus introduction from the Eurasian territories and reveal a dynamic pattern of avian influenza virus evolution within the Nigerian poultry population.

In 2021, amidst the COVID-19 pandemic and global food insecurity, the Nigerian poultry sector was yet exposed to highly pathogenic avian influenza (HPAI) virus and its economic challenges. Between 2021 and 2022, HPAI caused 467 outbreaks reported in 31 of the 37 administrative regions in Nigeria. In this study, we characterized the genome of 97 influenza A viruses of the subtypes H5N1, H5N2 and H5N8 identified in different agro-ecological zones and farms during the 2021-2022 epidemic. The phylogenetic analysis of the HA genes showed widespread distribution of the H5Nx clade 2.3.4.4b and similarity with the HPAI H5Nx viruses detected in Europe since late 2020. Topology of the phylogenetic trees indicates the occurrence of several independent introductions of the virus into the country followed by a regional evolution of the virus most probably linked to its persistent circulation in West African territories. An additional evidence of the evolutionary potential of HPAI viruses circulating in this region is the identification in this study of a putative H5N1/H9N2 reassortant virus in a mixed-species commercial poultry farm. Our data confirm Nigeria as a crucial hotspot for HPAI virus introduction from the Eurasian territories and reveal a dynamic pattern of avian influenza virus evolution within the Nigerian poultry population.

African swine fever (ASF) has been endemic in sub-Saharan Africa since the 1960s. Following its introduction in Senegal, in 1957, ASF steadily progressed through West Africa, reaching Burkina Faso in 2003, and later Mali in 2016. Despite the heavy burden of disease on pig production, little information is available on the genetic diversity of Africa swine fever virus (ASFV) in Burkina Faso, Mali and Senegal. Here, we used real-time PCR ASFV to detect the ASFV genome in samples collected between 1989 and 2016, in Burkina Faso, Mali and Senegal, and conventional approaches for isolate characterization. The C-terminal end of the p72 protein gene, the full E183L gene and the central variable region (CVR) within the B602L gene in ASFV genome were sequenced and compared to publicly available sequences. ASFV genome was found in 27 samples, 19 from Burkina Faso, three from Mali and five from Senegal. The phylogenetic analyses showed that all viruses belong to genotype I, with the ASFVs from Burkina Faso and Mali grouping with genotype Ia and ASFV serogroup 4, and those from Senegal with genotype Ib and the ASFV serogroup 1. The analysis of the CVR tetrameric tandem repeat sequences (TRS) showed four TRS variants in Burkina Faso, two in Senegal and one in Mali. The three countries did not share any common TRS, and all CVRs of this study differed from previously reported CVRs in West Africa, except for Senegal. Three of the five isolates from Senegal fully matched with the CVR, p72 and p54 sequences from ASFV IC96 collected during the 1996 ASF outbreak in Ivory Coast. This study shows the spread of the same ASFV strains across countries, highlighting the importance of continuous monitoring of ASFV isolates. It also calls for an urgent need to establish a regional plan for the control and eradication of ASF in West Africa.

PURPOSE OF REVIEW: The purpose of this review is to consolidate exposure assessment methods for occupational research on engineered nanomaterials (ENMs) published within the past five years (2015–2020). RECENT FINDINGS: The three ENMs that generated the highest volume of new research include titanium dioxide, graphene, and aluminum oxide. A multi-metric approach, using both online and offline instruments and analyses has been found to be a useful method to characterize ENM workplace exposures and was commonly used in the recently published literature. Particle number concentration was the most common online exposure metric used, followed by the metrics of mass and surface area. There are currently no consensus methods for offline analyses of most ENMs. Researchers generally used gravimetric or elemental analyses for carbonaceous nanomaterials, titanium dioxide, and other nanometals, but there was little overlap between other ENM materials reviewed. Using biological markers of exposure, such as urinary oxidative stress biomarkers, as an indication of chronic exposure may also be useful for some ENMs and should be further researched. SUMMARY: Generally, similar online instrumentation and offline electron microscopy methods were used for all ENMs. However, this consistency was not observed for offline mass analysis methods within specific ENMs. Consolidation of the most recent methods and results of exposure assessments within this broad material category can guide researchers towards future areas of study. Establishing consensus methods of exposure assessment for each individual ENM is crucial to characterizing workplace exposures, pooling data to fully understand their associated risks, and developing useful occupational exposure limits.

The objective of this study was to describe the epidemiological and clinical aspects as well as the therapeutic methods of mycetomical lesions.This was a longitudinal retrospective study, which included all patients treated for mycetoma from January 2016 to December 2018 including two years of recruitment and one year of monitoring (2019). The study concerned 19 patients who were hospitalized and treated in the department of surgery.Patients represented 2.3% of hospitalizations and consisted of 11 males and 8 females with an average age of 38 years with extremes of 15 - 70 years, and an average time between the onset of symptoms and presentation to the hospital of 10 years (range 1 - 40 years). Eight livestock breeders and seven farmers were concerned, 14 of whom have started the disease after trauma. The foot was involved in 13 patients. Twelve suffered from osteoarticular lesions. Black grains were present in 16 cases attributed toMycetoma should be discussed and diagnosed at an early stage in predisposed patients particularly in farmers and breeders. Prevention is necessary; it is based on wound disinfection and wearing safety shoes.

The duties of home healthcare workers are extensive. One important task that is frequently performed by home healthcare workers is administration of nebulized medications, which may lead to significant dermal exposure. In this simulation study conducted in an aerosol exposure chamber, we administered a surrogate of nebulizer-delivered medications (dispersed sodium chloride, NaCl) to a patient mannequin. We measured the amount of NaCl deposited on the exposed surface of the home healthcare worker mannequin, which represented the exposed skin of a home healthcare worker. Factors such as distance and position of the home healthcare worker, room airflow rate and patient's inspiratory rate were varied to determine their effects on dermal exposure. There was a 2.78% reduction in dermal deposition for every centimeter the home healthcare worker moved away from the patient. Increasing the room's air exchange rate by one air change per hour increased dermal deposition by about 2.93%, possibly due to a decrease in near field particle settling. For every 10-degrees of arc the home healthcare worker is positioned from the left side of the patient toward the right and thus moving into the ventilation airflow direction, dermal deposition increased by about 4.61%. An increase in the patient's inspiratory rate from 15-30 L/min resulted in an average of 14.06% reduction in dermal deposition for the home healthcare worker, reflecting a relative increase in the aerosol fraction inhaled by the patient. The findings of this study elucidate the interactions among factors that contribute to dermal exposure to aerosolized pharmaceuticals administered by home healthcare workers. The results presented in this paper will help develop recommendations on mitigating the health risks related to dermal exposure of home healthcare workers.

Rift Valley fever virus (RVFV) outbreaks have considerable impact on human and animal health. Here, we are reporting a serosurvey of cattle from all regions of Mali. These demonstrated that few had been exposed to RVFV from 2005 to 2014. Recent outbreaks of RVF in Niger and a single human case in Mali provide justification for further entomological and ecological studies of this virus.

A high percentage (up to 90%) of dromedary camels in the Middle East as well as eastern and central Africa have antibodies to Middle East respiratory syndrome coronavirus (MERS-CoV). Here we report comparably high positivity of MERS-CoV antibodies in dromedary camels from northern Mali. This extends the range of MERS-CoV further west in Africa than reported to date and cautions that MERS-CoV should be considered in cases of severe respiratory disease in the region., Highlights • Dromedary camels in northern Mali have serological evidence of exposure to MERS-CoV. • 88% of camels tested were ELISA positive. • 78% of camels had neutralizing antibodies. • MERS should be considered to be present in northern Malian camels.

Cette étude présente les résultats d’une enquête sérologique qui évalue le statut épidémiologique de la peste des petits ruminants (PPR) d’ovins et de caprins de différentes régions du Mali. Les animaux ont été testés par Elisa de compétition (c-Elisa) afin d’évaluer la séroprévalence par région prospectée, ainsi que par espèce, classe d’âge et sexe. Les résultats indiquent un taux individuel de séroprévalence de 42,6 p. 100 [intervalle de confiance à 95 p. 100 (IC95) : 40,9 - 44,3]. Une variation significative de la séroprévalence a été observée entre les différentes régions allant de 5,5 p. 100 (IC95 : 3,3 - 7,7) à Gao (la région avec la plus faible prévalence) à 55,6 p. 100 (IC95 : 52,2 - 59,1) à Koulikoro (la région avec la plus forte prévalence). Une différence significative (p < 0,05) a été observée entre les prévalences estimées des femelles et des mâles, et entre celles des animaux adultes (> 3 ans) et des plus jeunes (< 3 ans), mais pas entre ovins et caprins. Ces résultats confirment la présence de la maladie à travers tout le territoire, avec une prévalence relativement élevée dans les régions du centre, du sud et de l’ouest. Ils montrent aussi que la maladie sévit probablement à l’état enzootique, soulignant la faiblesse du programme de vaccination contre la PPR au Mali. Ils révèlent l’urgence de mettre en place un plan de vaccination efficace afin de protéger le cheptel contre cette maladie contagieuse.

Au Mali, les pertes en reproduction constituent des contraintes majeures à l’amélioration de la productivité de l’élevage des petits ruminants. Parmi les causes de ces pertes qui demeurent mal connues figurent, entre autres, l’infertilité, les avortements, l’orchite et la chétivité. L’objet de la présente étude a été d’évaluer la prévalence sérologique de la fièvre Q dans les élevages de petits ruminants où des cas de pertes en reproduction ont été observés, ainsi que la valeur financière des pertes liées aux avortements enregistrés. L’étude a été conduite entre 2006 et 2009 dans les zones agropastorales des localités de Bougouni (région de Sikasso), Nioro (région de Kayes), Kéniébougouwéré (région de Ségou) et Koro (région de Mopti). Sur les 718 sérums analysés par la méthode Elisa indirecte, 155 (21,5 ± 3 p. 100) se sont révélés positifs aux anticorps de Coxiella burnetii. Cette prévalence a varié en fonction des sites et du rang de portée. La prévalence la plus élevée a été observée à Kéniébougouwéré (35 ± 6 p. 100), suivi de Nioro (28,5 ± 7,5 p. 100), puis de Bougouni (10,8 ± 4,6 p. 100), et la plus faible à Koro (5,8 ± 3,7 p. 100). Des études complémentaires intégrant le diagnostic moléculaire (technique PCR) pourraient aider à élucider le rôle étiologique de cette pathologie dans les cas de pertes en reproduction couramment enregistrés chez les petits ruminants au Mali. L’analyse technico-économique a permis d’évaluer la valeur financière des pertes.

Background Bovine tuberculosis (BTB) is a contagious, debilitating human and animal disease caused by Mycobacterium bovis, a member of the Mycobacterium tuberculosis complex. The study objective were to estimate the frequency of BTB, examine genetic diversity of the M. bovis population in cattle from five regions in Mali and to determine whether M. bovis is involved in active tuberculosis (TB) in humans. Samples from suspected lesions on cattle at the slaughterhouses were collected. Mycobacterial smear, culture confirmation, and spoligotyping were used for diagnosis and species identification. Mycobacterium DNA from TB patients was spoligotyped to identify M. bovis. Results In total, 675 cattle have been examined for lesions in the five regions of Mali. Out of 675 cattle, 79 specimens presented lesions and then examined for the presence of M. bovis. Thus, 19 (24.1 %) were identified as M. bovis; eight (10.1 %) were non-tuberculous Mycobacterium (NTM). Nineteen spoligotype patterns were identified among 79 samples with five novel patterns. One case of M. bovis (spoligotype pattern SB0300) was identified among 67 TB patients. Conclusion This study estimates a relatively true proportion of BTB in the regions of Mali and reveals new spoligotype patterns.

A Bayesian approach, allowing for conditional dependence between two tests was used to estimate without gold standard the sensitivities of complement fixation test (CFT) and competitive enzyme-linked immunosorbent assay test (cELISA) and the serological prevalence of CBPP in a cattle population of the Central Delta of the Niger River in Mali, where CBPP is enzootic and the true prevalence and animals serological state were unknown. A significant difference (P = 0.99) was observed between the sensitivities of the two tests, estimated at 73.7% (95% probability interval [PI], 63.4-82.7) for cELISA and 42.3% (95% PI, 33.3-53.7) for CFT. Individual-level serological prevalence in the study population was estimated at 14.1% (95% PI, 10.8-16.9). Our results indicate that in enzootic areas, cELISA performs better in terms of sensitivity than CFT. However, negative conditional sensitivity dependence between the two tests was detected, implying that to achieve maximum sensitivity, the two tests should be applied in parallel.

Internet addiction is ''an individual's inability to control their Internet use, which in turn leads to feelings of distress and functional impairment of daily activities'' [Shapira, N., Lessig, M., Goldsmith, T., Szabo, S., Lazoritz, M., Gold, M. et al. (2003). Problematic Internet use: Proposed classification and diagnostic criteria. Depression and Anxiety, 17(4), 207-216]. Previous research in this field has offered inconclusive data on whether Internet addiction can be classified as a disorder. This study provides an in-depth and comprehensive analysis of internet addiction through a meta-synthesis of qualitative studies on excessive Internet use published during the period of 1996-2006. Several constructs pertaining to the domain of Internet addiction have been identified and a theoretical model of Internet addiction has been proposed.

A serological survey to determine the prevalence of contagious bovine pleuropneumonia (CBPP) in Mali was carried out by using the competitive enzyme linked-immunosorbent test (c-ELISA) on 8007 serum samples systematically collected from 199 cattle herds collected throughout the whole country. Results showed a national prevalence of 18.11 % at the individual level and 85.93 % at the herd level. Significant variations in the individual prevalence were observed between regions of the country and ranged from 4.63 % in Tombouctou to 54.88 % in Kidal. At the herd level, although there were variations between regions, a high prevalence was constantly observed ranging from 60 to 100 %, hence confirming the endemic nature of the disease across the country. The CBPP risk varied also between regions and was very low in Tombouctou (odds ratio (OR) = 0.4) but very high in Kidal (OR = 9.8). Similarly, the risk seemed higher in the animals of the over 3-year age group (OR = 1.6) compared to the other age groups. It was also observed that there was a slightly higher risk (OR = 1.3) in the females than in the males. This study confirms the presence of CBPP across the country and should help to elaborate strategies for the effective control of the disease.

A respiratory disease of lambs that has been termed the 'coughing syndrome' has been observed in the mid-western region of the United States of America. Mycoplasma ovipneumoniae (M. ovipneumoniae) and Mycoplasma arginini (M. arginini) were routinely isolated from the respiratory tract of lambs with this disease. A high level of antibodies reactive with ovine cilia of the upper respiratory tract was detected in the sera from many of the lambs in affected flocks but not in sera of lambs from unaffected flocks. The reactivity of these antibodies with cilia was demonstrated by ELISA and confirmed by indirect immunofluorescent staining and western immunoblotting. These antibodies were predominantly of the IgG isotype. They were distinct from cold or warm agglutinins and could be absorbed from the sera with cilia but not with antigens of common bacterial pathogens of the sheep respiratory tract including M. ovipneumoniae, M. arginini, Pasteurella haemolytica, Pasteurella multocida or Neisseria ovis. In addition, their occurrence appeared to be independent of the specific antibodies to M. ovipneumoniae and M. arginini. Western immunoblotting indicated that the antibodies were directed primarily against an antigen with apparent molecular weight of 50 kDa. In one flock from which serial serum samples were collected from the same lambs over a 10-month period, antibodies to ovine cilia developed before the onset of the clinical disease and persisted for a period of several months until most of the lambs had apparently recovered. However, colonization of the respiratory tract of the lambs by M. ovipneumoniae preceded the production of these antibodies. Sequential serum samples taken from another flock, with no known history of this coughing, showed no such antibodies throughout the sampling period. It is suggested that an immunopathologic mechanism involving production of autoantibodies directed against a ciliary antigen of the lambs could be a contributing factor to the pathogenesis of this clinical disease.

International audience; A better understanding of how T1 vaccination confers immunity would facilitate the rational design of improved vaccines against contagious bovine pleuropneumonia (CBPP). We show here that mycoplasmas-induced recall proliferation and IFN-gamma responses are detected in cattle that received multiple shots of T1 vaccines. These anamnestic responses were under the strict control of CD4(+) T lymphocytes. Moreover, CD62L expression indicated that both CD4(+) effector memory (Tem) and central memory (Tcm) T lymphocytes are elicited in these animals. Comparative analysis with data from cattle that completely recovered from CBPP infection revealed similar anamnestic T-cell responses albeit at a lower magnitude for T1-vaccinated animals, particularly in the Tcm compartment. In conclusion, we discuss how our current understanding of T-cell responses will contribute to ongoing efforts for the improvement of future CBPP vaccines.

Sera obtained from dairy cattle in communal corral herds located near the city of Bamako in Mali, West Africa were sceeened using the microscopic agglutination test against 26 serovars representing 15 serogroups of Leptospira interrogans. Forty five percent (44.8%; 288/642) were positive to one or more serovars. This seroprevalence rate likely reflects infection since vaccination against leptospiral infection has not been practiced i Mali. The rate was higher among females. The most common titers were against antigens of serovars cynopteri (14.7%), hardjo (13.3%), pomona (9.2%), nona (8.1%), kambale (6.5%), grippotypyosa (6.4%), hebdomadis (6.2%), and pyrogenes (5.2%).

Genes of the Mycoplasma mycoides subsp . mycoides small colony biotype ( Mmm SC) coding for proteins capable of eliciting protective T-cell memory responses have potential for incorporation into a recombinant subunit vaccine against contagious bovine pleuropneumonia (CBPP). Here we used lymphocytes from cattle that had completely recovered from infection to screen products of Mmm SC genes for recognition by CD4 + effector memory (Tem) and central memory (Tcm) T lymphocytes. Six Mmm SC genes ( abc , gapN , glpO , lppA , lppB , and ptsG ) were expressed as histidine-tagged recombinant polypeptides, or synthetic overlapping peptides, before inclusion in proliferation and gamma interferon (IFN-γ) assays. Only two Mmm SC antigens, LppA and PtsG, consistently induced recall proliferation from immune CD4 + T cells and IFN-γ production in all animals tested. Moreover, LppA and PtsG were shown to possess epitopes recognized by both short-lived CD4 + Tem and long-lived CD4 + Tcm cells.

This study reports the results of a meta-analysis of empirical studies on Internet addiction published in academic journals for the period 1996–2006. The analysis showed that previous studies have utilized inconsistent criteria to define Internet addicts, applied recruiting methods that may cause serious sampling bias, and examined data using primarily exploratory rather than confirmatory data analysis techniques to investigate the degree of association rather than causal relationships among variables. Recommendations are provided on how researchers can strengthen this growing field of research.

A better understanding of protective immune memory against contagious bovine pleuropneumo- nia (CBPP) is needed in order to facilitate the development of safer vaccines based on selected components of the pathogen. For this purpose, cells collected from lymph nodes draining the lungs of Mycoplasma my- coides subsp. mycoides small colony biotype (MmmSC)-infected cattle were stimulated with the pathogen in vitro and evaluated concurrently for proliferation (CFSE based method), expression of activation, mem- ory markers and cytokine production. Direct evidence is presented for a major contribution of CD4 + T cells to the vigorous proliferative and T1 biased cytokine recall responses observed in cattle that have recov- ered from infection but not in animals developing the acute form of the disease. Two different phenotypes of MmmSC-specific memory CD4 were observed based on CD62L expression and proliferative capacities. Furthermore, recall proliferation of B cells also occurred but was strictly dependent on the presence of CD4. The information provided in this study will facilitate the search for MmmSC antigens that have potential for the development of subunit vaccines against CBPP. contagious bovine pleuropneumonia/ Mycoplasma mycoides subsp. mycoides SC / vaccine / memory / CD4

International audience; The purpose of the present study was to characterize the Mycoplasma mycoides subsp. mycoides small colony (MmmSC)-specific humoral immune response at both systemic and local levels in cattle experimentally infected with MmmSC, for a better understanding of the protective immune mechanisms against the disease. The disease was experimentally reproduced in zebu cattle by contact. Clinical signs, postmortem and microbiological findings were used to evaluate the degree of infection. Serum and bronchial lavage fluids (BAL) were collected sequentially, before contact and over a period of one year after contact. The kinetics of the different antibody isotypes to MmmSC was established. Based on the severity of the clinical signs, post mortem and microbiological findings, the animals were classified into three groups as acute form with deaths, sub-acute to chronic form and resistant animals. Seroconversion was never observed for the control animals throughout the duration of the experiment, nor for those classified as resistant. Instead, seroconversion was measured for all other cattle either with acute or sub-acute to chronic forms of the disease. For these animals, IgM, IgG1, IgG2 and IgA responses were detected in the serum and BAL samples. The kinetics of the IgM, IgG1 and IgG2 responses was nearly similar between both groups of animals. No evident correlation could thus be established between the levels of these isotypes and the severity of the disease. Levels of IgA were high in both BAL and serum samples of animals with sub-acute to chronic forms of the disease, and tended to persist throughout the entire experimental period. In contrast, animals with acute forms of the disease showed low levels of IgA in their BAL samples with none or very transient but low levels of IgA in the serum samples. Our results thus demonstrated that IgA is produced locally in MmmSC experimentally infected cattle by contact and may play a role in protection against contagious bovine pleuropneumonia.

International audience; Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides biotype Small Colony (MmmSC), is still a major cattle disease in Africa. Development of long-term protective vaccines, the only relevant strategy to achieve CBPP eradication, requires the characterisation of the protective immune mechanism. To this aim, the present study investigated the cellular immune response persisting in the lymph nodes of cattle infected naturally and experimentally by contact, one year post exposure. The lymph node cell composition, MmmSC responsiveness and phenotype of the MmmSC-responding lymphocytes were compared between animals according to the different outcomes of the infection. To unravel the protective mechanism, the study focussed on the MmmSC-specific memory immune response generated in recovered cattle, known to develop long-term immunity and to be resistant to reinfection. An MmmSC-specific immune response, mediated by IFN$\gamma$-secreting CD4 T-cells, was detected in the lymph nodes of all recovered cattle. Furthermore, the magnitude of this immune response was significantly higher in animals with complete recovery than in recovered animals presenting lung sequestra. The findings suggest that, in recovered cattle, a subset of MmmSC-primed IFN$\gamma$-secreting CD4 T-cells homed to the regional lymph nodes as MmmSC-specific memory T-cells, likely responsible for the protective anamnestic response. Induction and expansion of this subset of MmmSC-specific CD4 memory T-cells might be a major goal to develop efficient long term protective vaccines against CBPP.

Ovine tracheal ring explants were infected with four different Mycoplasma ovipneumoniae and one M. arginini field isolate and their ability to induce cytopathic effects was tested by measuring ciliary activity and intracellular calmodulin release. Infected tracheal rings showed significantly decreased ciliary activity as compared to the non-infected control rings. There were, however, marked differences between isolates in the onset and severity of the effects which correlated with their ability to produce hydrogen peroxide. Infected tracheal rings released more calmodulin than the non-infected controls. The amount of calmodulin released also varied between isolates, and somewhat reflected the degree of loss of ciliary activity in the corresponding rings induced by the different isolates. Light and electron microscopic examinations of infected tracheal rings revealed disorganisation and sloughing of the epithelium, and association of mycoplasmas only with the cilia. Following repeated in vitro passages, the organisms had reduced ability to inhibit ciliary activity which correlated with decreased hydrogen peroxide production. Addition of catalase to the organ cultures delayed loss of ciliary activity. These results suggest that M. ovipneumoniae induced ciliostasis in ovine tracheal ring explants which correlated with hydrogen peroxide production. Furthermore, these M. ovipneumoniae-induced injuries to respiratory epithelial cells could contribute to the role that this organism may play in sheep respiratory disease.

Normal sheep alveolar macrophages collected by bronchial lavage were exposed to live or heat-killed Mycoplasma ovipneumoniae organisms, and their capability to ingest Staphylococcus aureus and to elicit antibody-dependent cellular cytotoxicity against sensitized chicken red blood cells was tested. Controls consisted of non-infected macrophages in M199 medium. In addition, the effect of M. ovipneumoniae on expression of surface molecules on these sheep alveolar macrophages was determined. The percentage of S. aureus ingested by nontreated sheep alveolar macrophages was significantly higher than that of infected macrophages. Live mycoplasmas were more effective in suppressing the ingestion of S. aureus by these macrophages than killed mycoplasmas. Both live and killed mycoplasmas suppressed the cytolytic effect of the sheep alveolar macrophages to a similar degree. About 78% and 45% of the normal sheep alveolar macrophages had IgG and complement receptors, respectively. Infection of these macrophages with M. ovipneumoniae decreased significantly the expression of IgG receptors but had no effects on complement receptors. There were substantial increases in the expression of both MHC class I and class II by the mycoplasma-induced macrophages as compared with unstimulated macrophages. Live mycoplasmas were more effective in inducing expression of both classes than killed mycoplasmas. The results, taken together, suggest that M. ovipneumoniae induced alterations in macrophage activities and this may be a contributing factor in the pathogenesis of respiratory disease induced by the organism.

"Syllable weight is usually viewed as a binary opposition…' (Hayes 1989) . That is, syllable weight distinctions are claimed to be at most binary: heavy vs light; bimoraic vs monomoraic. This paper argues that further distinctions of syllable weight are necessary to account for certain phonological processes. I argue and show that Pulaar (a dialect of Fula), makes a four way weight distinction. In addition, the analysis adopted in this paper shows that previous analyses of Pulaar metrical structure are inadequate.

Lors d’une enquête sérologique sur les petits ruminants, 396 sérums dont 77 ovins et 319 caprins ont été prélevés dans différentes régions du Mali. Ces sérums ont été analysés par le test Elisa indirect pour la recherche d’anticorps contre l’agalactie contagieuse à Mycoplasma agalactiae chez les petits ruminants. Les résultats obtenus ont montré un taux global de prévalence de 8,3 p. 100 (33/396), avec une répartition différente selon les troupeaux, la prévalence ayant pu atteindre 37,5 p. 100. Aussi, la répartition des sérums positifs par groupe à risque a montré un pourcentage plus élevé (60,6 p. 100, soit 20/33) dans les troupeaux ayant eu un historique pathologique de troubles respiratoires associés à des problèmes de lactation que dans les troupeaux apparemment sains (9,1 p. 100, soit 3/33) ou que dans les troupeaux de statut inconnu (30,3 p. 100, soit 10/33). Puisque la vaccination contre l’agalactie contagieuse des petits ruminants n’est pas pratiquée au Mali, ces résultats reflètent certainement l’infection et montrent la nécessité d’effectuer des sondages microbiologiques pour isoler les espèces de mycoplasmes impliquées, afin d’établir une épidémiologie plus précise.

Reunion a Dakar en mars 1979. Trois directions se degagent des exposes: le developpement a partir des valeurs traditionnelles, la tradition comme facteur de developpement, la necessite d'une contribution pluridisciplinaire a l'etude de ces problemes.