DOI: 10.5061/dryad.wpzgmsbzk
title: Host-parasite relationship in urban environments: A network analysis of hemoparasite infections in Nasua nasua Linnaeus (South American coati)

description: Parasite relationships are influenced by host size, behavior, population
 density, and location, and can affect the ecological dynamics of their
 hosts. Urban environments provide new contexts for host-parasite
 interactions, often leading to changes in infection dynamics when compared
 with the natural environment. This study focuses on the relationship
 between five genera of hemoparasites (Anaplasma Theiler,
 EhrlichiaMoshkovski, Hepatozoon Miller, hemotropic Mycoplasma Nowak, and
 Neorickettsia Philip) found in the South American coati Nasua nasua
 Linnaeus (Carnivora: Procyonidae), a carnivore highly adaptable to urban
 areas. Here, we used network analysis to verify the interaction between N.
 nasua and hemoparasites. Also, we used General Linear Model to investigate
 the influence of biotic and abiotic variables and hemoparasite infections
 on the functional roles of N. nasua individuals, considering weight, age,
 sex, and tick infestation (number of immature ticks collected). The
 network revealed low modularity, and none of the biotic variables,
 immature stages of ticks, and location of sampling had any influence on
 the functional role of N. nasua. The most important hemoparasite in the
 network was hemotropic Mycoplasma, identified as a key non-hub connector,
 probably spreading efficiently through frequent agonistic social
 interactions from N. nasua. These findings underscore the complex
 interplay between host behavior, environmental factors, and parasite
 ecology in urban environments, offering insights into managing urban
 wildlife diseases.
description: <strong>Study Area</strong> South
 American coatis were captured in two areas within the city of Campo
 Grande, located in the state of Mato Grosso do Sul, Brazil, in the
 central-western region of the country: (i) <em>Parque Estadual do
 Prosa </em>(PEP), a conservation unit in the core of Campo Grande
 with 135 hectares, and (ii) private area of the Air Force Village (AFV), a
 complex of 197 hectares divided into a military operational zone and a
 residential area inhabited by at least 730 humans with their domestic
 animals (Barreto et al. 2024). The predominant vegetation in Campo Grande
 is Cerrado, a tropical savanna that is characterized by hot, semi-humid
 summers and distinct seasonal variations, with a dry period from April to
 October and a rainy season from November to March (Barreto et al. 2021)
 (Figure 1). <strong>Trapping
 Procedures</strong> South American coatis were
 captured every three weeks for ten consecutive days from March 2018 to
 April 2019 using 80 metal traps (1 m × 0.40 m × 0.50 m), with 40 traps per
 area. The traps were strategically placed to ensure human accessibility
 and shade, covering most of the PEP and AFV areas. Captured animals were
 anesthetized with a combination of tiletamine hydrochloride and zolazepam
 hydrochloride (Telazol, Zoetis® New Jersey, USA) at approximately 6 mg/kg,
 intramuscularly. After chemical restraint, animals were marked with
 numbered color-coded ear tags, and a microchip was implanted
 subcutaneously between the shoulder blades for future identification. Each
 animal was measured, and its age was estimated according to Olifiers et
 al. (2010). Blood was collected from the femoral vein using tubes
 containing EDTA (ethylenediamine tetraacetic acid), then transferred to
 RNAse/DNAse-free cryotubes and stored at -80°C until molecular analysis. A
 thorough inspection for ectoparasites was conducted by a single person on
 the entire body of the individual for three minutes. Ticks were removed
 with forceps, stored in 100% alcohol, and identified to the genus (larvae)
 or species (nymphs and adults) using a stereomicroscope following
 taxonomic literature (Dantas-Torres et al., 2019; Martins et al. 2010).
  All specimens were deposited in the Acari Collection of Instituto
 Butantan, São Paulo, Brazil. All experimental
 procedures were approved by the Instituto Chico Mendes de Biodiversidade
 (ICMBio) under SISBIO license 49662-8, the Ethics Committee on Animal Use
 of the School of Agricultural and Veterinary Sciences, UNESP (CEUA
 FCAV/UNESP 06731/19), the Ethics Committee on Animal Use of Universidade
 Católica Dom Bosco (CEUA UCDB 001/2018), and the Air Force Cooperation
 Agreement (Nº01/GAP-CG/2018). <strong>Parasite
 Sampling</strong> DNA was extracted from 200 µL
 of blood using the Illustra Blood Mini Kit (GE Healthcare®, Chicago, IL,
 USA), following the manufacturer's instructions. To assess the
 quality of the extracted DNA and avoid false-negative results, the DNA
 samples were tested using PCR targeting the mammalian
 <em>gapdh</em> gene (Birkenheuer et al. 2003). Ultra-pure
 sterile water (Life Technologies®, Carlsbad, CA, USA) was used as a
 negative control in the PCR assays. PCR screening for
 <em>Anaplasma</em>, <em>Ehrlichia</em>,
 <em>Hepatozoon</em>, hemotropic
 <em>Mycoplasma</em>, and <em>Neorickettsia</em>
 was conducted by targeting specific genes for each genus, as described by
 Perles (2022a; b; 2023a; b). <strong>Network
 structure</strong> To examine the relationships
 among the detected hemoparasites, we used a modularity network metrics (M)
 (Sano et al. 2024). To assess the significance of network metrics, Monte
 Carlo procedures were employed, comparing the observed metrics with 1,000
 random matrices generated from null models. We generated them based on the
 original weighted matrix using the algorithm proposed by Pinheiro et al.
 (2019). Significance was determined when the network structure deviated
 significantly from the null model at p &lt; 0.05. Subsequently, to
 evaluate the relative importance of each node in the network structure, we
 computed the individual role for each South American coati<em>
 </em>and each parasite species. This involved determining their
 network functional role, classifying nodes based on their position and
 significance within the network. The classifications included (i)
 ultraperipheral vertices (all interactions within their module), (ii)
 peripheral vertices (most interactions within their module), (iii) non-hub
 connector vertices (many interactions to other modules), (iv) non-hub
 kinless vertices (interactions evenly distributed among all modules), (v)
 provincial hubs (most interactions within their module), (vi) connector
 hubs (many interactions to most other modules), and (vii) kinless hubs
 (interactions homogeneously distributed among all modules) (Mello et al.
 2013; Queiroz et al. 2021). For the network construction we used the
 'igraph' package (Csardi and Nepusz 2006), and the host-parasite
 interaction incidence matrix was handled with the 'Bipartite'
 package (Dormann et al. 2008; Dormann 2011).
 <strong>Relationship between biotic and abiotic variables
 in infections</strong> A variety of specific
 statistical models were assessed to investigate the influence of
 covariates (explanatory variables) on each parasite species' role
 within South American coatis. The examined variables included: (i) weight;
 (ii) age; (iii) sex; (iv) quantities of immature ticks collected from each
 individual (Perles et al. 2022c); and (v) collection area. Additionally, a
 full model (all variables) and null model, devoid of any variables, were
 established. The species role of each coati was treated as a categorical
 variable, representing distinct categories. To appropriately model this
 response variable, the analysis was conducted utilizing generalized linear
 models (GLM) with the multinomial family, which allowed us to account for
 the multiple, unordered categories effectively. All candidate models were
 compared in a model selection approach based on Akaike information
 criterion corrected for small samples (AICc) (Akaike 1974), considering as
 plausible all models with ΔAICc ≤ 2, using the package ‘AICcmodavg’
 version 2.3–1 (Mazerolle 2020). All data were analyzed using R
 4.2.1.
description: # Host-parasite relationship in urban environments: A network analysis of
 hemoparasite infections in Nasua nasua Linnaeus (South American coati)
 [https://doi.org/10.5061/dryad.wpzgmsbzk](https://doi.org/10.5061/dryad.wpzgmsbzk) ## Description of the data and file structure ### Files and variables #### File: ALL.R: Script used to run the analyses. **File 01:** Column A: **Sample Identification (ID)** – VBA refers to coati’s individuals captured in the Air Force Village (Vila da Base Aérea in Portuguese) with an Arabic number associated with the order of new individuals captured. The PEP codes refer to coatis individuals captured in Prosa States Park (*Parque Estadual do Prosa*in Portuguese) and the number is associated to the order of coati captured. When a coati was recaptured, a letter “B” was also assigned, indicating that it is the same individual, but in different moments. Column B to F: Infection of hemoparasites – refers to the following hemoparasites, respectively: *Hepatozoon*, *Neorickettsia*, *Ehrlichia*, *Anaplasma*, and *Mycoplasma*. The 1 refers to the presence of parasites in the molecular tests and the 0 refers to being negative in the molecular test. **File 02:** Column A: **Sample Identification (ID)** – VBA refers to coati’s individuals captured in the Air Force Village (Vila da Base Aérea in Portuguese) with an Arabic number associated with the order of new individuals captured. The PEP codes refer to coatis individuals captured in Prosa States Park (*Parque Estadual do Prosa*in Portuguese) and the number is associated to the order of coati captured. When a coati was recaptured, a letter “B” was also assign, indicating that is the same individual, but different moments. Column B: collection month Column C to F: Biological information about coatis, such as sex (Female or Male) , age (Adult or Juvenile), weight (g) and quantities of immature ticks collected from each individual Column G: Classification of the functional role of the network of each sampled coati **Code/software** All data were analyzed using R 4.2.1.1 (R Core Team 2022).