Staphylococcus aureus Host Spectrum Correlates with Methicillin Resistance in a Multi-Species Ecosystem.

Although antibiotic resistance is a major issue for both human and animal health, very few studies have investigated the role of the bacterial host spectrum in its dissemination within natural ecosystems. Here, we assessed the prevalence of methicillin resistance among Staphylococcus aureus (MRSA) isolates from humans, non-human primates (NHPs), micromammals and bats in a primatology center located in southeast Gabon, and evaluated the plausibility of four main predictions regarding the acquisition of antibiotic resistance in this ecosystem. MRSA strain prevalence was much higher in exposed species (i.e., humans and NHPs which receive antibiotic treatment) than in unexposed species (micromammals and bats), and in NHP species living in enclosures than those in captivity-supporting the assumption that antibiotic pressure is a risk factor in the acquisition of MRSA that is reinforced by the irregularity of drug treatment. In the two unexposed groups of species, resistance prevalence was high in the generalist strains that infect humans or NHPs, supporting the hypothesis that MRSA strains diffuse to wild species through interspecific transmission of a generalist strain. Strikingly, the generalist strains that were not found in humans showed a higher proportion of MRSA strains than specialist strains, suggesting that generalist strains present a greater potential for the acquisition of antibiotic resistance than specialist strains. The host spectrum is thus a major component of the issue of antibiotic resistance in ecosystems where humans apply strong antibiotic pressure.

Preliminary assessment of gastrointestinal parasites of the sun-tailed monkey (Allochrocebus solatus) in a semi-free-ranging colony.

BACKGROUND: The occurrence of gastrointestinal parasites in the sun-tailed monkey (Allochrocebus solatus) at the CIRMF primatology center is unknown. We, therefore, assessed the presence and richness (number of different parasite taxa) of gastrointestinal parasites in a semi-free-ranging colony of A. solatus. METHODS: A total of 46 fecal samples were screened using a modified McMaster technique for fecal egg counts. RESULTS: In the 46 samples collected, seven taxa of gastrointestinal parasites, including protozoa and nematodes were identified. The most prevalent parasite was strongyles parasites (98%), followed by Trichuris spp. (72%), Strongyloides spp. (67%) and Entamoeba coli (65%). Balantioides coli (33%), Endolimax nana (25%), and Spirurid eggs (26%) were only found in a minority of the animals. CONCLUSIONS: This study contributes new host records of gastrointestinal parasites in semi-free-ranging A. solatus and highlights the need to investigate the health of this species and implement proper precautions in the management of this colony.

Surgical Treatment of Oesophagostomum spp. Nodular Infection in a Chimpanzee at the CIRMF Primatology Center, Gabon.

Oesophagostomosis is a zoonotic disease caused by nematodes of the genus Oesophagostomum in the intestinal walls of many species, including ruminants, pigs, humans, and nonhuman primates. Although great apes appear to tolerate the parasite in the wild, they can develop a clinical form that can lead to death in captivity and the natural environment. At the Primatology Centre of the International Centre for Medical Research in Franceville (CIRMF) in Gabon, we recorded 4 deaths of chimpanzees (Pan t. troglodytes) caused by Oesophagostomum spp. between 2015 and 2019. In each case, coprological analysis was positive for strongylid eggs and abdominal ultrasound revealed nodules about 4 cm in diameter on the intestinal and abdominal walls. Albendazole treatments administered by mouth in two doses of 400 mg six months apart resulted in the disappearance of the parasite in coprological samples but the chimpanzees still died. Autopsies carried out on all four chimpanzees revealed a rupture of the cysts and a discharge of pus into the abdomen in each case. We report surgical management involving the removal of Oesophagostomum spp. cysts from a chimpanzee following coprological analysis and abdominal ultrasound examination. Surgical exploration confirmed the fragility of the cystic walls, the rupture of which we avoided. This 5th new case of Oesophagostomum ssp. nodules recovered without complications following the operation and could rejoin his group. We suggest that surgical intervention should be considered in similar cases in captive primates, especially chimpanzees.

Diversity of gastrointestinal parasites in sympatric mammals in Moukalaba-Doudou National Park, Gabon.

BACKGROUND AND AIM: Gastrointestinal parasites identified in the wild can negatively affect host fitness, lower performance, and growth. On the other side, sympatric mammals that share habitat and resources may also cross-transmit parasites, which are often zoonotic and can contribute to morbidity and mortality. This study aimed to characterize the diversity of gastrointestinal parasites circulating in mammalian hosts in Moukalaba-Doudou National Park. MATERIALS AND METHODS: We screened a total of 25 fecal samples collected from nine wild mammalian species, namely, western gorilla (Gorilla gorilla gorilla), chimpanzee (Pan troglodytes), putty-nosed monkey (Cercopithecus nictitans), African forest elephant (Loxodonta cyclotis), African buffalo (Syncerus caffer), blue duiker (Philantomba monticola), bay duiker (Cephalophus dorsalis), and red river hog (Potamochoerus porcus) as well as people working as trackers (Homo sapiens) using direct microscopic observations following a sedimentation technique to concentrate the fecal material. RESULTS: Of the total 25 fecal samples screened, 15 (60%) were positive for parasitic gastrointestinal infection. Based on the morphology of parasite eggs and cysts, we identified a rich diversity of nematodes, protozoans, trematodes, and cestodes, including unidentified strongyles (73%), Oesophagostomum spp. (53%), Ancylostoma spp. (27%), Trichuris spp. (13%), Ascaris spp. (13%), Mammomonogamus spp. (13%), Strongyloides spp. (47%), Balantidium coli (20%), Entamoeba coli (20%), Endolimax nana (6%), Fasciola hepatica (6%), Paramphistomum spp. (13%), and Taenia spp. (6%). CONCLUSION: All parasites were found at least once in one of the hosts, and most were potentially zoonotic and responsible for several diseases of public health concern. Because of the small sample size, our findings should not be considered conclusive. Nevertheless, they highlight the diversity of gastrointestinal parasites in this area.

A New Species of Sucking Louse from the Mandrill from Gabon with a Review of Host Associations and Geographical Distributions, and Identification Keys to Members of the Genus pedicinus (Phthiraptera: Anoplura: Pedicinidae).

Members of the sucking louse genus Pedicinus are ectoparasites of cercopithecid primates in Africa, Asia, and Gibraltar. Pedicinus gabonensis n. sp. is described on the basis of adult male and female specimens collected from the mandrill (Mandrillus sphinx) in Gabon. The new species is compared morphologically with other members of the genus Pedicinus, and a nuclear elongation factor 1 alpha gene sequence is provided. Host associations and geographical distributions of the 18 previously recognized species of the genus and of P. gabonensis n. sp. are reviewed. Updated identification keys are provided for males and females of all known valid species of Pedicinus.

The host specificity of ape malaria parasites can be broken in confined environments.

Recent studies have revealed a large diversity of Plasmodium spp. among African great apes. Some of these species are related to Plasmodium falciparum, the most virulent agent of human malaria (subgenus Laverania), and others to Plasmodium ovale, Plasmodium malariae and Plasmodium vivax (subgenus Plasmodium), three other human malaria agents. Laverania parasites exhibit strict host specificity in their natural environment. Plasmodium reichenowi, Plasmodium billcollinsi, Plasmodium billbrayi and Plasmodium gaboni infect only chimpanzees, while Plasmodium praefalciparum, Plasmodium blacklocki and Plasmodium adleri are restricted to gorillas and Plasmodium falciparum is pandemic in humans. This host specificity may be due to genetic and/or environmental factors. Infrastructures hosting captive primates, such as sanctuaries and health centres, usually concentrate different primate species, thus favouring pathogen exchanges. Using molecular tools, we analysed blood samples from captive non-human primates living in Gabon to evaluate the risk of Plasmodium spp. transfers between host species. We also included blood samples from workers taking care of primates to assess whether primate-human parasite transfers occurred. We detected four transfers of Plasmodium from gorillas towards chimpanzees, one from chimpanzees to gorillas, three from humans towards chimpanzees and one from humans to mandrills. No simian Plasmodium was found in the blood samples from humans working with primates. These findings demonstrate that the genetic barrier that determines the apparent host specificity of Laverania is not completely impermeable and that parasite exchanges between gorillas and chimpanzees are possible in confined environments.

Molecular characterization of Orf virus in goats in Gabon, Central Africa.

BACKGROUND: Orf or contagious ecthyma is a zoonotic viral infection with a potential serious health threat for the small ruminants industry as well as humans. It is currently emerging in new territories. RESULTS: Eight suspected clinical cases of pustular dermatitis in goats occurred in the rural area of Tebe, in south-eastern Gabon, in January 2013. The orf virus (ORFV) was detected by high-throughput sequencing on sera, buccal swabs and scab pool samples. It was confirmed in six out of eight sick goats by using specific PCR targeting the major envelope protein (B2L) and the orf virus interferon resistance (VIR) genes. Phylogenetic analysis revealed that the Gabonese strain and South Korean strains evolved from a common ancestor, suggesting an Asian origin of the ORFV' Gabonese strain. CONCLUSIONS: This study provides the molecular detection of the ORFV strain involved in the cases of pustular dermatitis in goats and highlights its circulation in Gabon.