Instituto Tecnológico de Chetumal

<ns4:p>Leishmaniasis is caused by an intracellular parasite transmitted to humans by the bite of a sand fly. It is endemic in Asia, Africa, the Americas, and the Mediterranean region. Worldwide, 1.5 to 2 million new cases occur each year, 350 million are at risk of acquiring the disease, and leishmaniasis causes 70,000 deaths per year. Clinical features depend on the species of<ns4:italic>Leishmania</ns4:italic>involved and the immune response of the host. Manifestations range from the localized cutaneous to the visceral form with potentially fatal outcomes. Many drugs are used in its treatment, but the only effective treatment is achieved with current pentavalent antimonials.</ns4:p>

The use of drones to study marine animals shows promise for the examination of numerous aspects of their ecology, behaviour, health and movement patterns. However, the responses of some marine phyla to the presence of drones varies broadly, as do the general operational protocols used to study them. Inconsistent methodological approaches could lead to difficulties comparing studies and can call into question the repeatability of research. This review draws on current literature and researchers with a wealth of practical experience to outline the idiosyncrasies of studying various marine taxa with drones. We also outline current best practice for drone operation in marine environments based on the literature and our practical experience in the field. The protocols outlined herein will be of use to researchers interested in incorporating drones as a tool into their research on marine animals and will help form consistent approaches for drone-based studies in the future.

Sharks and rays are key functional components of coral reef ecosystems, yet many populations of a few species exhibit signs of depletion and local extinctions. The question is whether these declines forewarn of a global extinction crisis. We use IUCN Red List to quantify the status, trajectory, and threats to all coral reef sharks and rays worldwide. Here, we show that nearly two-thirds (59%) of the 134 coral-reef associated shark and ray species are threatened with extinction. Alongside marine mammals, sharks and rays are among the most threatened groups found on coral reefs. Overfishing is the main cause of elevated extinction risk, compounded by climate change and habitat degradation. Risk is greatest for species that are larger-bodied (less resilient and higher trophic level), widely distributed across several national jurisdictions (subject to a patchwork of management), and in nations with greater fishing pressure and weaker governance. Population declines have occurred over more than half a century, with greatest declines prior to 2005. Immediate action through local protections, combined with broad-scale fisheries management and Marine Protected Areas, is required to avoid extinctions and the loss of critical ecosystem function condemning reefs to a loss of shark and ray biodiversity and ecosystem services, limiting livelihoods and food security.

Hydrogen atoms (H) Fluorine atoms (F) Chlorine atoms (Cl) Bromine atoms (Br) Iodine atoms (I) Sulphur atoms (S) Sodium atoms (Na) Potassium atoms (K) Radicals containing one carbon atom

Currently, freshwater zooplankton sampling and identification methodologies have remained virtually unchanged since they were first established in the beginning of the XX century. One major contributing factor to this slow progress is the limited success of modern genetic methodologies, such as DNA barcoding, in several of the main groups. This study demonstrates improved protocols which enable the rapid assessment of most animal taxa inhabiting any freshwater system by combining the use of light traps, careful fixation at low temperatures using ethanol, and zooplankton-specific primers. We DNA-barcoded 2,136 specimens from a diverse array of taxonomic assemblages (rotifers, mollusks, mites, crustaceans, insects, and fishes) from several Canadian and Mexican lakes with an average sequence success rate of 85.3%. In total, 325 Barcode Index Numbers (BINs) were detected with only three BINs (two cladocerans and one copepod) shared between Canada and Mexico, suggesting a much narrower distribution range of freshwater zooplankton than previously thought. This study is the first to broadly explore the metazoan biodiversity of freshwater systems with DNA barcodes to construct a reference library that represents the first step for future programs which aim to monitor ecosystem health, track invasive species, or improve knowledge of the ecology and distribution of freshwater zooplankton.

BACKGROUND: The larvae of the botfly Dermatobia hominis cause furunculoid myiasis in endemic areas. Lack of knowledge of this condition outside these areas leads to confusion in diagnosis and delays appropriate treatment. OBJECTIVE: To describe the clinical findings of furunculoid myiasis encountered in Quintana Roo, in the south-east of Mexico. MATERIALS AND METHODS: We performed an observational study on 25 cases diagnosed over a period of 4 years. RESULTS: Diagnosis of furunculoid myiasis was made in 14 males and 11 females with an average age of 24.5 years. Most of our patients were students, farmers, or housewives. The number of lesions varied from one to four. In 20% of cases, more than one parasite was present in each lesion. The scalp was the most commonly affected region (40%), followed by the trunk and the extremities. Doppler ultrasound study (DUSG) of the furuncle-like lesions confirmed the clinical diagnosis in all cases. CONCLUSIONS: Furunculoid myiasis is frequent in the state of Quintana Roo, Mexico. We found no association with occupation, gender, social background or age. DUSG can be used to evaluate the number of parasites per furunculoid lesion avoiding misdiagnoses and treatment delays.

Carbon footprint is one of the most widely used tools for assessing the environmental impacts of the production and utilization of concrete as well as of the components derived from it, representing the amount of carbon dioxide and other greenhouse gases associated with this product, expressed as CO 2 equivalents. In this paper, carbon footprint was used to compare the environmental performance in the production phase of a concrete made with both recycled and crushed virgin limestone aggregates, using a life cycle analysis methodological approach. Research outcomes revealed, as expected, that carbon dioxide equivalent emissions decreased slightly as the use of recycled aggregates increased. Emissions for concrete with 0.5 w/c were between 347 and 351 kg of CO 2 ‐ e /m 3 . It was also corroborated that cement is the material with the greatest influence on greenhouse gas emission generation in the concrete’s production phase, regardless of the use of recycled or virgin aggregates.

AIM: We aimed to assess the resistance rates of antimicrobial-resistant, in bacterial pathogens of epidemiological importance in 47 Mexican centers. MATERIAL AND METHODS: In this retrospective study, we included a stratified sample of 47 centers, covering 20 Mexican states. Selected isolates considered as potential causatives of disease collected over a 6-month period were included. Laboratories employed their usual methods to perform microbiological studies. The results were deposited into a database and analyzed with the WHONET 5.6 software. RESULTS: In this 6-month study, a total of 22,943 strains were included. Regarding Gram-negatives, carbapenem resistance was detected in ≤ 3% in Escherichia coli, 12.5% in Klebsiella sp. and Enterobacter sp., and up to 40% in Pseudomonas aeruginosa; in the latter, the resistance rate for piperacillin-tazobactam (TZP) was as high as 19.1%. In Acinetobacter sp., resistance rates for cefepime, ciprofloxacin, meropenem, and TZP were higher than 50%. Regarding Gram-positives, methicillin resistance in Staphylococcus aureus (MRSA) was as high as 21.4%, and vancomycin (VAN) resistance reached up to 21% in Enterococcus faecium. Acinetobacter sp. presented the highest multidrug resistance (53%) followed by Klebsiella sp. (22.6%) and E. coli (19.4%). CONCLUSION: The multidrug resistance of Acinetobacter sp., Klebsiella sp. and E. coli and the carbapenem resistance in specific groups of enterobacteria deserve special attention in Mexico. Vancomycin-resistant enterococci (VRE) and MRSA are common in our hospitals. Our results present valuable information for the implementation of measures to control drug resistance.

Aim: This study aims to assess the changes in antimicrobial resistance among some critical and high-priority microorganisms collected previously and during the coronavirus disease 2019 (COVID-19) pandemic in Mexico. Methods: We collected antimicrobial susceptibility data for critical and high-priority microorganisms from blood, urine, respiratory samples, and from all specimens, in which the pathogen may be considered a causative agent. Data were stratified and compared for two periods: 2019 versus 2020 and second semester 2019 (prepandemic) versus the second semester 2020 (pandemic). Results: In the analysis of second semester 2019 versus the second semester 2020, in blood samples, increased resistance to oxacillin (15.2% vs. 36.9%), erythromycin (25.7% vs. 42.8%), and clindamycin (24.8% vs. 43.3%) ( p ≤ 0.01) was detected for Staphylococcus aureus , to imipenem (13% vs. 23.4%) and meropenem (11.2% vs. 21.4) ( p ≤ 0.01), for Klebsiella pneumoniae . In all specimens, increased ampicillin and tetracycline resistance was detected for Enterococcus faecium ( p ≤ 0.01). In cefepime, meropenem, levofloxacin, and gentamicin ( p ≤ 0.01), resistance was detected for Escherichia coli ; and in piperacillin-tazobactam, cefepime, imipenem, meropenem, ciprofloxacin, levofloxacin, and gentamicin ( p ≤ 0.01), resistance was detected for Pseudomonas aeruginosa . Conclusion: Antimicrobial resistance increased in Mexico during the COVID-19 pandemic. The increase in oxacillin resistance for S. aureus and carbapenem resistance for K. pneumoniae recovered from blood specimens deserves special attention. In addition, an increase in erythromycin resistance in S. aureus was detected, which may be associated with high azithromycin use. In general, for Acinetobacter baumannii and P. aeruginosa , increasing resistance rates were detected.

A new genus is established in Eunicidae: Fauchaldius gen. nov., a symbiont of hexactinellid sponges that has only subacicular hooks, with F. cyrtauloni sp. nov. as its type species. Nine new species are described in Eunice: E. hernandezi sp. nov., E. ibarzabalae sp. nov., E. mikeli sp. nov. and E. nonatoi sp. nov. all belonging to the fuscusbidentate group; E. edwinlinkae sp. nov., E. hartmanae sp. nov., E. lanai sp. nov., and E. miurai sp. nov. all belonging to the flavus-tridentate group; and E. donathi sp. nov. that belongs to the fuscus-unidentate group. Further, two new species are described in Marphysa: M. angeli sp. nov. that is grouped with species having only composite falcigers, and M. orensanzi sp. nov. that belongs to the group with composite falcigers and composite spinigers. A key to identify genera in Eunicidae is included. A key to identify species of Eunice is appended.

AIM: This report presents phenotypic and genetic data on the prevalence and characteristics of extended-spectrum β-lactamases (ESBLs) and representative carbapenemases-producing Gram-negative species in Mexico. MATERIAL AND METHODS: A total of 52 centers participated, 43 hospital-based laboratories and 9 external laboratories. The distribution of antimicrobial resistance data for Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae complex, Acinetobacter baumannii complex, and Pseudomonas aeruginosa in selected clinical specimens from January 1 to March 31, 2020 was analyzed using the WHONET 5.6 platform. The following clinical isolates recovered from selected specimens were included: carbapenem-resistant Enterobacteriaceae, ESBL or carbapenem-resistant E. coli, and K. pneumoniae, carbapenem-resistant A. baumannii complex, and P. aeruginosa. Strains were genotyped to detect ESBL and/or carbapenemase-encoding genes. RESULTS: Among blood isolates, A. baumannii complex showed more than 68% resistance for all antibiotics tested, and among Enterobacteria, E. cloacae complex showed higher resistance to carbapenems. A. baumannii complex showed a higher resistance pattern for respiratory specimens, with only amikacin having a resistance lower than 70%. Among K. pneumoniae isolates, blaTEM, blaSHV, and blaCTX were detected in 68.79%, 72.3%, and 91.9% of isolates, respectively. Among E. coli isolates, blaTEM, blaSHV, and blaCTX were detected in 20.8%, 4.53%, and 85.7% isolates, respectively. For both species, the most frequent genotype was blaCTX-M-15. Among Enterobacteriaceae, the most frequently detected carbapenemase-encoding gene was blaNDM-1 (81.5%), followed by blaOXA-232 (14.8%) and blaoxa-181(7.4%), in A. baumannii was blaOXA-24 (76%) and in P. aeruginosa, was blaIMP (25.3%), followed by blaGES and blaVIM (13.1% each). CONCLUSION: Our study reports that NDM-1 is the most frequent carbapenemase-encoding gene in Mexico in Enterobacteriaceae with the circulation of the oxacillinase genes 181 and 232. KPC, in contrast to other countries in Latin America and the USA, is a rare occurrence. Additionally, a high circulation of ESBL blaCTX-M-15 exists in both E. coli and K. pneumoniae.

Cuticular hydrocarbons from the ponerine ant Ectatomma ruidum Roger and a highly integrated eucharitid myrmecophile, Kapala sulcifacies (Cameron), associated with it, have been characterized. Ninety hydrocarbons were identified from the ant, 55 hydrocarbons from the female wasp and 54 hydrocarbons from the male wasp. The wasps and ants share 40 hydrocarbons. These shared 40 hydrocarbons represent 92.6% of their hydrocarbon composition for female Kapala, 84.3% for male Kapala and 67.7% for the ants. The wasps have a carbon number range of C27 to C35; the ants have a range of C23 to C35. Both species possess n-alkanes, C27 to C33 for the wasps, C23 to C34 for the ants. Both species also possess major quantities of Z-7- and Z-9 alkenes: C29 to C33 for the wasps; C23 to C35 for the ants. The female wasps possess a low amount of a conjugated C31 diene (neither the ants nor the male wasps possess this hydrocarbon), and the ants, but not the wasps, contain low quantities of nonconjugated dienes (carbon numbers of C23 to C29) with double bonds at Δ9, and Δ14. Both wasps and ants share homologous series of 3-, 5-, 10-, 11-, 12-, 13-, 15- and 17-methyl branched alkanes. Ants and wasps also share a homologous series of 3,7-dimethyl alkanes. Other internally branched dimethyl alkanes are found in both ants and wasps, but only 11, 15-DiMeC29 is shared. Wasps have 7, 15- and 10, 14-dimethyl alkanes while the ants have 15,19-dimethyl alkanes. Kapala sulcifacies and E. ruidum both possess hydrocarbons of the 5, X-, 11, X-, 12, X- and 13, X-DiMe series, but the compounds involved are not shared because they represent different compounds. Behavioral observations indicate that the ants accept the newly emerged adult parasitoids with no evidence of agonistic behavior for a period of time after adult eclosion. Nevertheless, the chemical deception is not completely efficient because young adult Kapala are soon ejected from the nest by transportation by their host. These transportations frequently occur after seizure at the base of the wasps’ characteristic scutellar spines, such structures allowing for easy transportation without injury for the parasite. Moreover, if no method of escaping the colony is provided, the ants ultimately attack the parasitoids. The substantial chemical overlap of the cuticular hydrocarbon profiles of the ants and wasps are discussed in the context of the social life of the colony.

In this paper, we demonstrate that zinc oxide (ZnO) layers deposited by inkjet printing (IJP) can be successfully applied to the low-temperature fabrication of efficient inverted polymer solar cells (i-PSCs).

The relative importance of ecology and evolution as factors determining species richness and composition of the helminth communities of fish is a matter of current debate. Theoretical studies use host-parasite lists, but these do not include studies on a temporal or spatial scale. Local environmental conditions and host biological characteristics are shown to influence helminth species richness and composition in four fish species (Eugerres plumieri, Hexanematichthys assimilis, Oligoplites saurus, and Scomberomorus maculatus) in Chetumal Bay, Mexico. With the exception of H. assimilis, the helminth communities had not been previously studied and possible associations between environmental and host biological characteristics as factors determining helminth species richness and composition using redundancy analysis (RDA) are described. Thirty-four helminth species are identified, with the highest number of species (19 total (mean = 6.3 +/- 2.1)) and the lowest (9 (4.0 +/- 1.0)) occurring in H. assimilis and S. maculatus, respectively. The larval nematodes Contracaecum sp. and Pseudoterranova sp. were not only the helminth species shared by all four host species but also were the most prevalent and abundant. Statistical associations between helminth community parameters and local ecological variables such as host habitat use, feeding habits, mobility, and time of residence in coastal lagoons are identified. Phylogeny is important because it clearly separates all four host species by their specialist parasites, although specific habitat and feeding habits also significantly influence the differentiation between the four fish species.

Abstract Tropical storms can shape the structure and productivity of mangrove forests. In this study, we compared current litterfall with historical tropical storm disturbance in the karstic Y ucatan P eninsula ( YP ). We also explored the relationship between litterfall and the fresh/seawater mixture of floodwater. Our hypotheses were that litterfall peaks at moderate perturbations and in sites where seawater dominates the floodwater mixture, and thus, where soil total phosphorus ( TP ) is relatively high. Litterfall was sampled for 2 yr, from eight mangrove forests around the YP . At each site, forest structure, interstitial salinity, TP , nitrogen, carbon, pH , and bulk density were measured. Our results show that mangrove forest from northeast YP are historically impacted by stronger and more frequent tropical storms compared with those in northwest and southeast YP , where tropical storm intensity is moderate and mild, respectively. Litterfall was higher in northwest YP (≥3 g/m 2 d) compared with northeast and southeast (≤ 2 g/m 2 d), mimicking a subsidy‐stress gradient where highest productivity is reached at moderate perturbations. Neither salinity nor forest structure alone satisfactorily explained litterfall variability. Soil TP followed a similar geographical pattern as the disturbance gradient: highest concentrations in the northwest YP (≥0.05%) and lowest in the northeast and southeast (≤ 0.03%). Thus, it is likely that TP , and not tropical storm disturbance, is the main driver of litterfall in mangrove forests of the YP . Alterations in TP availability ( e.g., sea level rise and aquifer contamination) have the potential to modify mangrove productivity in the region.

The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960's, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed.

Abstract Vampyroteuthis infernalis Chun, 1903, is a widely distributed deepwater cephalopod with unique morphology and phylogenetic position. We assessed its habitat and trophic ecology on a global scale via stable isotope analyses of a unique collection of beaks from 104 specimens from the Atlantic, Pacific and Indian Oceans. Cephalopods typically are active predators occupying a high trophic level (TL) and exhibit an ontogenetic increase in δ 15 N and TL. Our results, presenting the first global comparison for a deep-sea invertebrate, demonstrate that V. infernalis has an ontogenetic decrease in δ 15 N and TL, coupled with niche broadening. Juveniles are mobile zooplanktivores, while larger Vampyroteuthis are slow-swimming opportunistic consumers and ingest particulate organic matter. Vampyroteuthis infernalis occupies the same TL (3.0–4.3) over its global range and has a unique niche in deep-sea ecosystems. These traits have enabled the success and abundance of this relict species inhabiting the largest ecological realm on the planet.

Bacterial cultures and chemical analyses were performed from cloacal and oral swabs taken from 43 American crocodiles Crocodylus acutus and 28 Morelet's crocodiles C. moreletii captured in Quintana Roo State, Mexico. We recovered 47 bacterial species (28 genera and 14 families) from all samples with 51.1% of these belonging to the family Enterobacteriaceae. Fourteen species (29.8%) were detected in both crocodile species and 18 (38.3%) and 15 (31.9%) species were only detected in American and Morelet's crocodiles, respectively. We recovered 35 bacterial species from all oral samples, of which 9 (25.8%) were detected in both crocodile species. From all cloacal samples, we recovered 21 bacterial species, of which 8 (38.1%) were detected in both crocodile species. The most commonly isolated bacteria in cloacal samples were Aeromonas hydrophila and Escherichia coli, whereas in oral samples the most common bacteria were A. hydrophila and Arcanobacterium pyogenes. The bacteria isolated represent a potential threat to crocodile health during conditions of stress and a threat to human health through crocodile bites, crocodile meat consumption or carrying out activities in crocodile habitat. We especially warn about the presence of Salmonella arizonae and S. typhi, which cause enteritis and septicemia in crocodiles and salmonellosis and typhoid fever in humans. The risk of bacterial contamination from crocodiles to humans could increase in the future because of the accelerated destruction of crocodile habitat, which could lead to an augmentation of human-crocodile interactions. Information on bacterial diversity reported here could help in the choice of antibacterial products in case of infections that are of crocodile origin.

The effect of pollutants on the intensity of infection of metazoan parasites in the Mayan catfish, Ariopsis assimilis was investigated. Data were collected on pollutants and metazoan parasites from 76 catfish from five localities in Chetumal Bay in October, 1996. Nineteen pollutants (pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs)) were found in the catfish livers. Heavy metal content was not determined. Nineteen metazoan parasite species were recovered. After controlling for fish length and sampling station, there was a significant negative linear relationship between the intensity of the larval digenean Mesostephanus appendiculatoides and 1,1,1,-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) concentrations. This negative relationship may be explained either by the effect of the pesticide on the mortality of (i) free-living larval forms, (ii) metacercariae in the fish, (iii) infected fish or (iv) intermediate host snails. There were significant differences between fish parasitized and not parasitized with M. appendiculatoides with respect to their DDT concentrations. There were also significant differences between the variances of the mean Clark's coefficient of condition values between catfish parasitized and not parasitized by M. appendiculatoides, with the variance of non-parasitized catfish being significantly larger. The results provided statistical evidence that DDT has a detrimental effect on M. appendiculatoides infection intensity. Furthermore, the significantly larger variance value of Clark's coefficient for non-parasitized fish suggested that DDT affects both the parasite and general host condition.

Abstract Three gonad-infecting species of Philometra Costa, 1845 were, for the first time, recorded from perciform fishes from estuarine and marine waters in South Carolina and Georgia, USA: Philometra charlestonensis sp. nov. from the scamp Mycteroperca phenax (Jordan et Swain) (Serranidae), P. saltatrix Ramachandran, 1973 from the bluefish Pomatomus saltatrix (Linnaeus) (Pomatomidae), and Philometra sp. from the Atlantic croaker Micropogonias undulatus (Linnaeus) (Sciaenidae). The new species is characterized mainly by males (body length 2.65–3.14 mm) with equally long, needle-like spicules (length 132–141 μm) and the gubernaculum (81–93 μm) bearing dorsal transverse lamella-like structures on its distal portion, the body length of gravid females (168–247 mm), the presence of a well-developed anterior bulbous inflation on the female oesophagus, and by the length of the first-stage larvae (544–597 μm). A key to gonad-infecting species of Philometra parasitizing marine and brackish-water fishes is provided.