Microbiota and anthropic interference on antimicrobial resistance profile of bacteria isolated from Brazilian maned-wolf (Chrysocyon brachyurus)

RESEARCH PAPER

Microbiota and anthropic interference on antimicrobial resistance profile of bacteria isolated from Brazilian maned-wolf (Chrysocyon brachyurus)

Olney Vieira-da-Motta^I; Luiz Antonio Eckhardt-de-Pontes^I; Melissa Paes Petrucci^I; Israel Pereira dos Santos^II; Isabel Candia Nunes da Cunha^II; Ronaldo Gonçalves Morato^III

^ILaboratório de Sanidade Animal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil

^IILaboratório de Reprodução e Melhoramento Genético Animal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil

^IIICentro Nacional de Pesquisa e Conservação de Mamíferos Carnívoros, Instituto Chico Mendes de Conservação da Biodiversidade, Instituto Pró-Carnívoros, Atibaia, SP, Brazil

^{Correspondence}

ABSTRACT

Both the study of Brazilian wild mammal fauna and the conditions that foster the preservation of endangered species, such as Brazilian Maned-wolf (Chrysocyon brachyurus), in wild life are of extreme importance. In order to study the resistance profile of microbiota bacterial colonizing Brazilian Maned-wolf, this work investigated samples from eight male captive and free roaming animals originating from different Brazilian geographical regions. Samples for microbiological purposes were collected with swabs and kept in appropriate transport medium. Using routine microbiological techniques, the isolated bacteria were tested toward antimicrobial drugs by the agar disk diffusion method. Results showed that all samples from wild animals were sensitive toward all drugs tested. Conversely, the resistance profile of bacteria isolated from captive animals varied among strains and animal body site location. Escherichia coli samples from prepuce, anus and ear showed multi-resistance toward at least four drugs, especially against erythromycin and tetracycline, followed by Proteus mirabilis and P. vulgaris strains isolated from anus and ear. Among Gram-positive bacteria, strains of coagulase-negative staphylococci showed multi-resistance mainly toward erythromycin and amoxicillin. The work discusses these findings and suggests that profile of multi-resistance bacteria from captive subjects may be attributed to direct contact with human or through lifestyle factors such as feeding, predation or contact of animals with urban animals such as birds, rodents, and insects from surrounding environments.

Key words: Maned-wolf, Chrysocyon brachyurus, microbiota, antimicrobial resistance, anthropic pressure, environment.

Introduction

The Maned-wolf (Chrysocyon brachyurus) is the largest south American canid and despite of its wide distribution pattern covering open areas of South America, this species is listed as a Near Threatened (IUCN, 2007). Antropic pressure threatens endangered species mainly through deforestation of native forests, causing loss of native foraging areas, and forces animals to seek alternatives (Margarido and Braga, 2004). The Brazilian Maned-wolf Chrysocyon brachyurus, belongs to the Canidae family of the Carnivora order and developed in the Brazilian central highlands in the Pleistocene. In its natural environment this species feed on fruits, insects, and small birds, mammals and reptiles (Carvalho and Vasconcelos, 1995; Reis et al., 2006). Studies have shown that human management interferes in the gut flora of captive wild animals, when they are fed commercially-prepared foods (Schwab et al., 2011). Gastrointestinal tracts harboring Salmonella in captive C. brachyurus kept in Brazilian Zoos have been studied, with the authors suggesting a physiological adaptation of the bacterium to the animals' gut (Gilioli and Silva, 2000).

In dogs, the natural cavities such as nasal, oral and prepuce can house several bacteria and fungi which under special conditions may lead host infection (Birchard and Sherding, 1998; Sturgees, 2001). Domestic dogs with pathogenic resistant bacteria can also represent risks of infection to their owners (Guardabassi et al., 2004). However, while in wild canidae no transmission of bacteria to human has been described to date, wild animals may indeed represent a zoonotic risk to humans (Chomel et al., 2007). Based on the profile of antimicrobial resistance of bacteria towards drugs, this work discusses the possible anthropic pressure on microbiota of Brazilian Maned-wolf maintained in captivity when compared with their wildlife counterparts.

Material and Methods

Eight Brazilian Maned-wolf specimens were enrolled in the present work, with two wildlife specimens coming from Serra da Canastra, MG, and the other six captive animals coming from Zoos, one from Sorocaba, SP, two from São Bernardo, SP, one from Volta Redonda, RJ, and two from two private reserves one from Mogim Mirim-SP and one from Araxá-MG. Animals were chemically restrained with 5 mg/kg de PV of Zoletil® (hydrocloridrate of tiletamina + zolazepan cloridrate - VIRBAC®) via IM (Cunha et al., 2007). Then samples from five previously selected body sites were collected: oral, nasal and ear cavities, and foreskin (prepuce) and perineal areas. Standard Stuart medium transport microbiological swabs (Copan®, Italy) were used and immediately conditioned to be analyzed in the laboratory. The following media (Acumedia®, USA) were used to isolate the microorganisms: Sabouraud agar, blood base agar supplemented with defibrinated sheep blood and McConkey agar. All inoculated mediuns were maintained at 37 °C incubation during 24-72 h, or as much as one week for the observation of fungi growth. After this, all colonies were characterized by morphotintorial Gram staining, and biochemical tests performed: catalase (Sigma, USA), coagulase (Laborclin, Brazil), oxidase (Dry slide test Difco, USA) and DNAse (DNAse agar, Merck, Germany). Colonies suspected as Pseudomonas spp. were also cultured on Cetremide agar (Merck, Germany). Colonies suspected to be Staphylococcus aureus were cultured on Vogel-Johnson agar (Acumedia®, USA). To differentiate micrococci from staphylococci, semi-solid O-F (Difco, USA) supplement with 1% glucose and 0.04 IU bacitracin (CEFAR, Brazil) tests were adopted. Standard strains Micrococcus luteus ATCC4698 and Staphylococcus aureus ATCC25923 were used as negative and positive controls, respectively, according to manufacturer instructions. Bacteria presenting clear zone around colonies above 10 mm were considered Micrococcus.

Bacteria were identified using Api ID32 Staph, Api ID32 Strep and Api ID32E, and interpretation was conducted by an automated system (miniApi, bioMèriéux, France). Malassezia pachydermatis yeast forms were classified by culture on Sabouraud agar in Petri dishes supplemented with and without sterile olive oil, following by incubation at 37 °C. All yeast colonies were checked by Gram staining and characteristic Malassezia forms were observed and M. pachydermatis growth in both medium guaranteed the species identification.

Antimicrobial assay

All bacteria identified were tested for sensibility towards 12 drugs for Gram-positive and 12 drugs for Gram-negative bacteria (Laborclin®, Brazil), by using the disk diffusion on agar method in Petri dishes containing 20 mL Muller Hinton agar (Acumedia®, USA) (CLSI, 2012). The drugs used for Gram-positive bacteria were amoxicillin (AMO, 10 μg), clindamycin (CLI, 2 μg), cephalotin (CFL, 30 μg), penicillin G (PEN, 10 U), oxacillin (OXA, 1 μg), tetracycline (TET 30 μg), ampicillin (AMP, 10 μg), erythromycin (ERI, 15 μg), sulphazotrim (SUL, 25 μg), gentamicin (GEN, 10 μg), cephoxitin (CFO, 30 μg) and vancomycin (VAN, 30 mg); and for Gram-negative bacteria the drugs were tetracyclin (TET, 30 μg), cloranphenicol (CLO, 30 μg), amoxicilin + clavulanic acid (AMC, 20/10 μg), gentamicin (GEN, 10 μg), cephoxitin (CFO, 30 μg), tobramicin (TOB, 10 μg), ampicillin (AMP, 10 μg), cephalotin (CFL, 30 μg), cotrimoxazole (SUT, 25 μg), enrofloxacin (ENO 5 μg), erythromycin (ERI, 15 μg) and ciprofloxacin (CIP, 5 μg).

All inoculums (0,5 McFarland scale) used for the above tests were prepared in sterile 0.95% saline solution and read (DO_{550 nm}) in photometer (Densimat, bioMérrieux, France). All experiments were performed in triplicate.

Toxin production by staphylococci

All staphylococci were tested for enterotoxin (SEA-SEE) and TSST-1 toxin production by the Membrane Over Agar (MOA) followed by immunodifusion methods, as described by other researchers (Braga et al., 2004). Positive controls and specific antibodies and antigen for toxin detection were kindly provided by Dr. Luis Simeão do Carmo, from Universidade Federal de Minas Gerais-UFMG (MG, Brazil). To identify toxin from bacteria the Ouchterlony immunodiffusion method in 1.2% Noble agar (Difco, USA) was employed using supernatant from MOA culture. A standard Food Research Institute model template was used to perforate wells for applying test samples. Each positive reaction was immersed for 72 hours in a 0.9% NaCl solution that was changed three times a day, followed by the staining step with Coomassie Blue R-250, for 30-60 min at RT. A gentle unstaining step was performed with a methanol: ethanol solution, and samples were photodocumented (Su e Wong, 1995).

Results

The results reported in Tables 1-4 show the microorganisms isolated of samples from Brazilian Maned-wolf, according to body sites investigated.

With respect to enterotoxin investigation, from all coagulase-negative staphylococci (CNS) and one S. intermedius tested for SEA-SEE, only one strain of CNS from a captive animal received from the Sorocaba Zoo was positive for enterotoxin A.

The results reported in Tables 5 and 6 show the antimicrobial resistance profile of Gram-positive cocci isolated from captive and wild Brazilian Maned-wolf, respectively, and according to body sites investigated.

The only coagulase-positve S. intermedius strain was isolated from the oral cavity of a captive animal and showed full resistance towards amoxicillin, penicillin, and cotrimoxazole, while showing intermediary resistance profile towards oxacillin. (Tables 3 and 6).

The data showed multirresistant E. coli isolated from captive specimens, and bacteria antimicrobial profile from free roaming animals were all sensitive to all drugs tested.

Discussion

In order to contextualize the results found in the present work, one must consider the peculiar way of life led by this species, as described before, especially their natural diet and management choice adopted by each institution in order to offer conditions for the survival of individuals under their care. Were proposed a comprehensive study of sources and movements of resistance genes among microorganisms, including physical forces, such as wind and water, and biological forces such as human activities and animals, insects and birds in general (Allen et al., 2010). C. brachyurus, also known as "lobo-guará" is an endangered mammal species in the Brazilian wild. The data showed the diversity of microorganisms colonizing the cavities investigated in males specimens of the Brazilian Maned-wolf. The profile of resistance and susceptibility of bacteria to the drugs tested showed important differences between animals in the wild and in captivity. The role of humans or animals, including insects and birds, as carriers and transmitters of resistant bacteria to captive Brazilian Maned-wolves is proposed. Salmonella-causing diarrhea in one captive C. brachyurus in Brazilian Zoo was reported, but no other animal presented clinical signals of gut disturbance caused by this species (Gilioli and Silva, 2000). Others have highlighted wild animals diseases as a relevant public health issue, such as the case of wild birds carrying enterobacteriaceae E. coli and Salmonella Typhimurium (Tsiodras et al., 2008). The detection of resistant bacteria in feces from wild Yellow-headed Blackbird was discussed, despite the absence of antimicrobial pressure in the environment (Gibbs et al., 2007). Some of the same antibiotic used to treat human pathogens, such as amoxicillin and erythromycin, are among the drugs used to treat disease, promote growth and improve feed efficiency in animals. (Sarmah et al., 2006). The E. coli resistance profile was shown to be affected by several drugs dispersed in an environmental myriad affecting animal wild fauna (Allen et al., 2011). Free range feral swine from Brazilian wetlands presented an expressive colonization of body sites by resistant bacteria which raised the issue of the participation of water in the environment as a dispersing agent of these microorganisms and their resistance profile towards drugs (Lessa et al., 2011). Here we have shown that captive and wild animals presented antibiotic resistant bacteria towards several drugs, including amoxicillin and erythromycin, but no confirmation as to what caused such a resistance, a question which needs additional investigation. Although some authors emphasize ongoing questions as to the influence of antimicrobial agricultural compounds on antimicrobial resistance and subtherapeutic exposure of bacteria, drugs of every important clinical class are utilized in agriculture, and human populations are exposed to antimicrobial-resistant pathogens via consumption of animal products as well as through widespread release into the environment (Silbergeld et al., 2008). It is also known that the selection pressure applied by the antibiotics that are used in clinical and agricultural settings has promoted the evolution and spread of genes that confer resistance, regardless of their origins (Allen et al., 2010). Finally, the study proposes that direct or indirect contact of humans and their subproducts with wild animals, such as the Brazilian Maned-wolf, could foster cross-contamination of captive animals since the resistance profile of bacteria isolated from animals in the wild clearly showed that antimicrobial pressure was insignificant on microorganisms isolated.

Acknowledgments

Vieira-da-Motta was supported by the Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (grant E-26/103.097/2008). Cunha, I.C.N. and Morato, R.G thanks Instituto Pró-Carnívoros-Projeto Lobo da Canastra.

Submitted: March 05, 2012

Approved: April 04, 2013

All the content of the journal, except where otherwise noted, is licensed under a Creative Commons License CC BY-NC.

• Allen SE, Boerlin P, Janecko N, Lumsden JS, Barker IK, Pearl DL, Reid-Smith RJ, Jardine C, (2011) Antimicrobial resistance in generic Escherichia coli isolates from wild small mammals living in swine farm, residential, landfill, and natural environments in Southern Ontario, Canada. Appl Environ Microbiol. 77:882-888.
• Allen HK, Donato J, Wang HH, Cloud-Hansen KA, Davies J, Handelsman J, (2010) Call of the wild: antibiotic resistance genes in natural environments. Nature Rev Microbiol 8:251-259.
• Birchard SJ, Sherding RG, (1998) Manual Saunders Clínica de Pequenos Animais São Paulo: Ed. Roca.
• Braga LC, Shupp JW, Cummings C, Jett M, Takahashi JA, Carmo LS, Chartone-Souza E, Nascimento AMA, (2004) Pomegranate extract inhibits Staphylococcus aureus growth and subsequent enterotoxin production. J Ethnopharm 96:335-339.
• Carvalho CT, Vasconcelos LEM, (1995) Disease, food and reproduction of the Maned-wolf Chrysocyon brachyurus (Illiger) (Carnivora, Canidae) in southeast Brazil. Rev Bras Zool 12:627-640.
• Chomel BB, Belotto A, François-Xavier M, (2007) Wildlife, Exotic Pets, and Emerging Zoonoses. Emerg Infect Dis 13:6-11.
• CLSI - Clinical Laboratory Standards Institute, (2012) Performance standards for antimicrobial susceptibility testing; Twenty-second informational supplement (M100-S22). Clinical Laboratory Standards Institute, Wayne, Pennsylvania, USA; 32: 3
• Cunha ICN, Morato RG, Santos IP, Quirino CR, (2007) Biometry of the reproductive system and the ejaculation response of maned wolf (Chrysocyon brachyurus) to electroejaculation procedure. Proceedings of the 6th International Symposium on Canine and Feline Reproduction & 6th Biannual European Veterinary Society for Small Animal Reproduction Congress 2008 - Vienna, Austria, p. 1-2.
• Gibbs PS, Kasa R, Newbrey JL, Petermann SR, Wooley RE, Vinson HM, Reed W, (2007) Identification, antimicrobial resistance profiles, and virulence of members from the family Enterobacteriaceae from the feces of Yellow-Headed Blackbirds (Xanthocephalus xanthocephalus) in North Dakota. Avian Dis 51:649-655.
• Gilioli R, Silva FA, (2000) Frequency of parasites and Salmonella infection in captive maned-wolf, Chrysocyon brachyurus, kept in zoos at the State of São Paulo, Brazil. Arq Bras Med Vet Zootec 52:337-341.
• Guardabassi L, Loeber ME, Jacobson A, (2004) Transmission of multiple antimicrobial-resistant Staphylococcus intermedius between dogs affected by deep pyoderma and their owners. Vet Microbiol 98:23-27.
• IUCN 2007, (2007) IUCN Red List of Threatened Species. http://www.iucnredlist.org
• Lessa SS, Paes RCS, Santoro PN, Mauro RA, Vieira-da-Motta O, (2011) Identification and antimicrobial resistance of microflora colonizing feral pig (Sus scrofa) of Brazilian pantanal. Braz J Microbiol 42:740-749.
• Margarido TCM, Braga FG, (2004) Mamíferos. In: Mikich, S.B., Bérnils, R.S. (Eds.). Livro Vermelho da Fauna Ameaçada no Estado do Paraná. Secretaria Estadual do Meio Ambiente, Instituto Ambiental do Paraná, Curitiba, p. 25-142.
• Reis NR, Peracchi AL, Pedro WA, Lima IP, (2006) Mamíferos do Brasil, 1ª ed, Londrina.
• Sarmah AK, Meyer MT Boxall AB, (2006). A global perspective on the use, sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VAs) in the environment. Chemosphere 65:725-759.
• Schwab C, Cristescu B, Northrup JM, Stenhouse GB, Gänzle M, (2011) Diet and environment shape fecal bacterial microbiota composition and enteric pathogen load of grizzly bears. PLoS One, 6:1-8.
• Silbergeld EK, Graham J, Price LB, (2008) Industrial food animal production, antimicrobial resistance, and human health. Annu Rev Public Health 29:151-169.
• Sturgees CP, (2001). Doenças do Trato Alimentar. In: Dunn, J.K. (Eds.) Tratado de Medicina Interna de Pequenos Animais. Ed. Roca, São Paulo, pp 367-443.
• Su YC, Wong ACL, (1995) Identification and purification of a new staphylococcal enterotoxin, H. Appl Environ Microbiol 61:1438-1443.
• Tsiodras S, Kelesidis T, Kelesidis I, Bauchinger U, Falagas M, (2008) Human infections associated with wild birds. J Infect 56: 83-108.

Publication Dates

• Publication in this collection
  27 Mar 2014
• Date of issue
  Dec 2013

History

• Received
  05 Mar 2012
• Accepted
  04 Apr 2013