Indicator microbes correlate with pathogenic bacteria, yeasts and helminthes in sand at a subtropical recreational beach site

Aims: Research into the relationship between pathogens, faecal indicator microbes and environmental factors in beach sand has been limited, yet vital to the understanding of the microbial relationship between sand and the water column and to the improvement of criteria for better human health protection at beaches. The objectives of this study were to evaluate the presence and distribution of pathogens in various zones of beach sand (subtidal, intertidal and supratidal) and to assess their relationship with environmental parameters and indicator microbes at a non‐point source subtropical marine beach. Methods and Results: In this exploratory study in subtropical Miami (Florida, USA), beach sand samples were collected and analysed over the course of 6 days for several pathogens, microbial source tracking markers and indicator microbes. An inverse correlation between moisture content and most indicator microbes was found. Significant associations were identified between some indicator microbes and pathogens (such as nematode larvae and yeasts in the genus Candida), which are from classes of microbes that are rarely evaluated in the context of recreational beach use. Conclusions: Results indicate that indicator microbes may predict the presence of some of the pathogens, in particular helminthes, yeasts and the bacterial pathogen Staphylococcus aureus including methicillin‐resistant forms. Indicator microbes may thus be useful for monitoring beach sand and water quality at non‐point source beaches. Significance and Impact of the Study: The presence of both indicator microbes and pathogens in beach sand provides one possible explanation for human health effects reported at non‐point sources beaches.     

Enterococcus species distribution among human and animal hosts using multiplex PCR

Aims: This study evaluated the use of Enterococcus species differentiation as a tool for microbial source tracking (MST) in recreational waters. Methods and Results: Avian, mammalian and human faecal samples were screened for the occurrence of Enterococcus avium, Enterococcus casseliflavus, Enterococcus durans, Enterococcus gallinarum, Enterococcus faecium, Enterococcus faecalis, Enterococcus hirae and Enterococcus saccharolyticus using multiplex PCR. Host‐specific patterns of Enterococcus species presence were observed only when data for multiple Enterococcus species were considered in aggregate. Conclusions: The results suggest that no single Enterococcus species is a reliable indicator of the host faecal source. However, Enterococcus species composite ‘fingerprints’ may offer auxiliary evidence for bacterial source identification. Significance and Impact of Study: This study presents novel information on the enterococci species assemblages present in avian and mammalian hosts proximate to the nearshore ocean. These data will aid the development of appropriate MST strategies, and the approach used in this study could potentially assist in the identification of faecal pollution sources.     

Intraspecific diversity and morpho-phenological Variation inPhaseolus lunatus L. from the Yucatan Peninsula, Mexico

The genetic diversity ofP. lunatus in the Yucatan Peninsula was assessed on the basis of its morphological and phenological characters. Our results were then discussed in relation to ethnobotanic information obtained about the intraspecific diversity recognized by farmers, their selection criteria, agronomic management, production purpose and percentage of cultivated area. Research was undertaken in one of the cultural subareas of Mesoamerica, the Lowland Maya area, where traditional agriculture has been more persistent and where high diversity ofP. lunatus landraces has been recorded. Four of the 13 cultural-geographic zones established for the origin of this culture were included, 160 farmers from 12 localities were interviewed, and 149 seed samples ofP. lunatus germplasm were collected and analyzed using six characters. A subset of these samples was grown under ex situ uniform growth conditions and analyzed using 28 characters. Ethnobotanical and morpho-phenological data indicated 30 putative distinct landraces, two wild, and two weedy variants, suggesting gene flow among them. Richness and diversity estimates were greatest, and evenness lowest, where there was: 1) minimal agricultural intensification, 2) wild and weedy populations, and 3) greater persistence of traditional culture. Results underscored the importance of establishing in situ conservation programs in these areas. Se estimó la diversidad genética deP. lunatus en la Península de Yucatán con base en caracteres fenológicos y morfológicos, y se discute en relatión a la informatión etnobotánica obtenida acerca de la diversidad intraespecífica reconocida por los campesinos, sus criterios de selectión, su manejo agronómico, el destino de la productión y el porcentaje de área cultivada. La investigation se llevó a cabo en una de las subáreas culturales de Mesoamérica en donde la agricultura traditional ha sido más persistente y en donde se ha reportado alta diversidad de cultivares deP. lunatus: las Tierras Bajas Mayas. Cuatro de las trece zonas geográfico-culturales establecidas en el origen de esta civilizatión fueron incluídas, 160 campesinos de 12 localidades fueron entrevistados y 149 muestras de semilla del germoplasma deP. lunatus fueron analizadas con base en 6 caracteres. Un subconjunto de estas muestras se cultivó bajo condiciones homogéneas de crecimiento ex situ y se analizó usando 28 caracteres. Los datos morfólogicos y etnobotánicos indicaron 30 cultivares putativos, dos variantes silvestres y dos arvenses, y sugirió flujo génico entre ellas. La riqueza y la diversidad fue mayor, y el predominio menor, donde hubo: 1) menor intensification agrícola, 2) poblaciones silvestres y arvenses deP. lunatus, y 3) mayor persistencia de cultura traditional. Los resultados resaltan la importancia de establecer programas de conservación in situ en estas áreas.     

Automated dead-end ultrafiltration of large volume water samples to enable detection of low-level targets and reduce sample variability

Aims

A Portable Multi‐use Automated Concentration System (PMACS) concentrates micro‐organisms from large volumes of water through automated dead‐end ultrafiltration and backflushing. The ability to detect microbial targets from ground, surface and cooling tower waters collected using standard methods was compared with samples from the PMACS in this study.

Methods and Results

PMACS (100 l) and standard grab samples (100–500 ml) were collected from sites in Florida and South Carolina, USA. Samples were analysed for the presence of faecal indicator bacteria (FIB; ground and surface water) or Legionella pneumophila (Lp; cooling tower water). FIB were enumerated by growth on selective media following membrane filtration or in IDEXX defined substrate media. Lp cells were detected by direct fluorescence immunoassay using FITC‐labelled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. FIB were found in PMACS samples from ground and surface waters when their concentrations were below detection limits in grab samples. The concentrations of Lp in cooling tower samples collected over 5 months were more consistent in PMACS samples than grab samples.

Conclusions

These data demonstrate that PMACS concentration is advantageous for water monitoring. FIB were detected in PMACS samples when their concentrations were below the detection limits of the standard methods used. PMACS processing provided more representative samples of cooling tower waters reducing sample variability during long‐term monitoring.

Significance and Impact of the Study

This study highlights the utility of PMACS processing for enhanced monitoring of water for low‐level microbial targets and for reducing sample variability in long‐term monitoring programmes.     

Covalently linked immunomagnetic separation/adenosine triphosphate technique (Cov‐IMS/ATP) enables rapid,in‐field detection and quantification of Escherichia coli and Enterococcus spp. in freshwater and marine environments

Aims: Developing a rapid method for detection of faecal pollution is among the critical goals set forth by the Environmental Protection Agency in its revision of water quality criteria. The purpose of this study is to devise and test covalently linked antibody–bead complexes for faecal indicator bacteria (FIB), specifically Escherichia coli or Enterococcus spp., in measuring water quality in freshwater and marine systems. Methods and Results: Covalently linked complexes were 58–89% more robust than antibody–bead complexes used in previous studies. Freshwater and marine water samples analysed using covalently linked immunomagnetic separation/adenosine triphosphate quantification technique (Cov‐IMS/ATP) and culture‐based methods yielded good correlations for E. coli (R = 0·87) and Enterococcus spp. (R = 0·94), with method detection limits below EPA recreational water quality health standards for single standard exceedances (E. coli– 38 cells per 100 ml; Enterococcus spp. – 25 cells per 100 ml). Cov‐IMS/ATP correctly classified 87% of E. coli and 94% of Enterococcus spp. samples based on these water quality standards. Cov‐IMS/ATP was also used as a field method to rapidly distinguish differential loading of E. coli between two stream channels to their confluence. Conclusions: Cov‐IMS/ATP is a robust, in‐field detection method for determining water quality of both fresh and marine water systems as well as differential loading of FIB from two converging channels. Significance and Impact of the Study: To our knowledge, this is the first work to present a viable rapid, in‐field assay for measuring FIB concentrations in marine water environments. Cov‐IMS/ATP is a potential alternative detection method, particularly in areas with limited laboratory support and resources, because of its increased economy and portability.     

Biodeterioration of Mayan archaeological sites in the Yucatan Peninsula, Mexico

Many of the monuments of the Mayan civilization are suffering deterioration caused by environmental factors (high temperatures and relative humidities), increasing contamination from natural and anthropogenic sources, and by the action of micro- and macro-biological communities. Archaeological sites and historical monuments in the Mayan area were constructed with different limestones which offer different resistances to degradation by the various types of contamination. Two different sampling sites were chosen at the archaeological site of Uxmal in the Yucatan Peninsula, Mexico. Heterotrophic bacteria, cyanobacteria and different fungi were isolated and classified taxonomically. The other archaeological site chosen for this study was the fortress of Tulum, located at the side of the Caribbean Sea and exposed to chloride of marine spray and sand erosion. In this case, heterotrophic aerobic and anaerobic bacteria, cyanobacteria and fungi were isolated from the four sampling areas selected. In both archaeological sites crust deposits were observed by using light microscopy, SEM and ESEM. Surface analyses were made by means of EDAX and electron microprobe. Possible mechanisms of stone decay, based on the type of microorganisms isolated, the physico-chemical characteristics of the constructional materials and environmental factors are discussed.     

Karyotype polymorphism in the cycad Zamia loddigesii (Zamiaceae) of the Yucatan Peninsula, Mexico

The cycad %amia loddigesii Miq. forms a morphologically variable complex on the Yucatan peninsula, Mexico. Several diploid chromosome numbers have been found in the species: In = 17, 24, 25, 26 and 27. Differing karyotypes and chromosome numbers were found in individuals of the same population and die karyotypes differ widely in numbers of metacentric and telocentric chromosomes present. Centrometric fission as well as pericentric inversions and unequal translocations are suggested to be the probable mechanisms for this karyotype variation. There appears to be a correlation between high chromosome number and increasing dryness of the habitats. Coupled with the strongly asymmetrical karyotypes, this suggests that karyotype evolution in Z- loddigesii is recent.     

Assessment of adenovirus,hepatitis A virus and rotavirus presence in environmental samples in Florianopolis,South Brazil

Aims: To assess the presence of human adenovirus (HAdV), hepatitis A (HAV) virus and rotavirus A (RV‐A) in environmental samples from the Southern region of Brazil and to provide viral contamination data for further epidemiological studies and governmental actions. Methods and Results: Water samples from various sources (seawater, lagoon brackish water, urban wastewater, drinking water sources‐with and without chlorination and water derived from a polluted creek) and oysters of two growing areas were analysed by enzymatic amplification (nested PCR and RT‐PCR), quantification of HAdV genome (qPCR) and viral viability assay by integrated cell culture‐PCR (ICC‐PCR). From June 2007 to May 2008 in a total of 84 water samples, 54 (64·2%) were positive for HAdV, 16 (19%) for RV‐A and 7 (8·3%) for HAV. Viability assays showed nonpositive samples for HAV; though, infectious viruses were confirmed for RV‐A (12·5%) and HAdV (88·8%). Oyster samples by PCR were positive for HAdV (87·5%) and RV‐A (8·3%), but none for HAV. Quantitative PCR in oysters showed means loads in genomic copies (gc) of 9·1 × 10⁴ gc g^?1 (oyster farm south) and 1·5 × 10⁵ gc g^?1 (oyster farm north) and in waters ranging from 2·16 × 10⁶ (lagoon water) to 1·33 × 10⁷ gc l^?1 (untreated drinking water). Conclusions: This study has shown a widespread distribution of the analysed viruses in this particular region with high loads of HAdV in the environment which suggests the relevance of evaluating these viruses as positive indicators of viral contamination of water. Significance and Impact of the Study: The environmental approach in this study provides data concerning the prevalence, viability and quantification of enteric viruses in environmental waters and oysters in the South region of Brazil and has indicated that their presence might pose a risk to population in contact with the environmental samples searched.     

Evaluation of methodology for detection of human adenoviruses in wastewater,drinking water,stream water and recreational waters

Aims: This study evaluates dialysis filtration and a range of PCR detection methods for identification and quantification of human adenoviruses in a range of environmental waters. Methods and Results: Adenovirus was concentrated from large volumes (50–200 l) of environmental and potable water by hollow fibre microfiltration using commercial dialysis filters. By this method, an acceptable recovery of a seeded control bacteriophage MS2 from seawater (median 95·5%, range 36–98%, n = 5), stream water (median 84·7%, range 23–94%, n = 5) and storm water (median 59·5%, range 6·3–112%, n = 5) was achieved. Adenovirus detection using integrated cell culture PCR (ICC‐PCR), direct PCR, nested PCR, real‐time quantitative PCR (qPCR) and adenovirus group F‐specific direct PCR was tested with PCR products sequenced for confirmation. Adenovirus was routinely detected from all water types by most methods, with ICC‐PCR more sensitive than direct‐nested PCR or qPCR. Group F adenovirus dominated in wastewater samples but was detected very infrequently in environmental waters. Conclusions and Implications: Human adenoviruses (HAdv) proved relatively common in environmental and potable waters when assessed using an efficient concentration method and sensitive detection method. ICC‐PCR proved most sensitive, could be used semiquantitatively and demonstrated virus infectivity but was time consuming and expensive. qPCR provided quantitative results but was c. ten‐fold less sensitive than the best methods.     

Allelochemicals from Stauranthus perforatus, a Rutaceous tree of the Yucatan Peninsula, Mexico

Aqueous leachates and a CHCl3-MeOH (1:1) extract of roots of Stauranthus perforatus showed a significant phytotoxic effect on Amaranthus hypochondriacus and Echinochloa crus-galli. Bioassay-directed fractionation of the active organic extract led to the isolation and characterization of ten secondary metabolites, which included two pyranocoumarins [xanthyletin (1) and 3-(1',1'-dimethylallyl)-xanthyletin (2)], four furanocoumarins [chalepensin (3), ammirin (4), chalepin (5) and 2'-isopropyl-psoralene (6)], two lignans [asarinin (7) and fargesin (8)], one sesquiterpene [4,5-epoxi-beta-caryophyllene (9)], and one alkamide [pellitorine (10)]. From these compounds, 2'-isopropyl-psoralene (6) or anhydromarmesin, is reported for the first time as a natural product, whereas compounds 4-10 are now reported as being present in S. perforatus. Metabolites 1, 3-5 and 10 caused significant inhibition of radicle growth of A. hypochondriacus and E. crus-galli. Furthermore, in a greenhouse experiment the decomposition of the leaves and roots in the soil had a significant inhibitory effect on the growth of weeds. The allelopathic action of the decomposition of roots was evident up to the sixth week of the experiment. The effect of leaves was comparable to that of DPCA (dimethyl tetrachloroterephthalate), a commercial herbicide. Finally different concentrations of Stauranthus root powder were combined with maize kernels and used to feed corn weevil. The treatments resulted in high mortality of this insect.     

Antioxidant activities in tropical marine macroalgae from the Yucatan Peninsula,Mexico

Extracts from 48 marine macroalgae species (17 Chlorophyta, 8 Phaeophyta and 23 Rhodophyta) from the coasts of Yucatan and Quintana Roo (Mexico) were evaluated for antioxidant activity. The antioxidant activity was measured with the DPPH (2,2-diphenyl-1-picrylhydrasyl) method, and the phenolic content of each extract were also evaluated. All species exhibited a DPPH radical scavenging activity, and three species (Avrainvillea longicaulis, Chondria baileyana and Lobophora variegata) demonstrated great antioxidant potential with very low oxidation index EC₅₀ (1.44 ± 0.01, 2.84 ± 0.07 and 0.32 ± 0.01 mg mL⁻¹, respectively), significantly equivalent to EC₅₀ of some commercial antioxidants such as α-tocopherol, ascorbic acid, BHA and BHT. Moreover, extracts of the most active species exhibited reducing activities, superoxide anion radical scavenging and inhibition of lipid peroxidation. These results suggest that some macroalgae from the Yucatan peninsula have a great antioxidant potential which could be considered for future applications in medicine, food production or cosmetic industry.     

Palm species richness,abundance and diversity in the Yucatan Peninsula,in a neotropical context

Species richness, abundance and diversity patterns in palm communities in the Yucatan Peninsula were compared at three sites with different forest types (semi‐deciduous, semi‐evergreen and evergreen), as well as different precipitation, geomorphology and soil depth. All individual palms, including seedlings, juveniles and adults, were identified and counted in forty‐five (0.25 ha) transects. A total of 46 000 individual palms belonging to 11 species from nine genera and two subfamilies were recorded. Palm richness, diversity and abundance were highest in the evergreen forest. Species from the subfamily Coryphoideae dominated the semi‐deciduous and semi‐evergreen forests while species from the subfamily Arecoideae dominated the evergreen forest. Seven species were found only in the evergreen forest. Chamaedorea seifrizii and Sabal yapa were found in all three forest types, while Thrinax radiata was found in the semi‐deciduous and semi‐ evergreen forests and Cocothrinax readii only in the semi‐evergreen forest. Compared to other neotropical palm communities, the richness and diversity in the Yucatan Peninsula are lower than in the western Amazon basin. Although palm richness and diversity on the Yucatan Peninsula were positively associated with precipitation, other variables, in particular soil depth and fertility as well as habitat heterogeneity (microtopography and canopy cover), need to be considered to better understand the observed patterns.     

Length‐weight relationships of three fish species collected by recreational fishing in the northern coast of Yucatan Peninsula,Mexico

Length‐weight relationship (LWR) was estimated for three fish species from the northern coast of Yucatan peninsula in the Gulf of Mexico. All specimens were monthly collected from September 2015 to October 2016 by recreational fishing (handlining). A total of 408 individuals (15 Calamus campechanus, 9 Opsanus beta and 384 Sphoeroides nephelus) were sampled and analyzed. Information regarding LWR data for one of these species were not yet available in FishBase database, two of them have limited data and a new record of maximum length is presented.     

Wildlife uses and hunting patterns in rural communities of the Yucatan Peninsula, Mexico

Background

Use of plant resources and ecosystems practiced by indigenous peoples of Mesoamerica commonly involves domestication of plant populations and landscapes. Our study analyzed interactions of coexisting wild and managed populations of the pitaya Stenocereus pruinosus, a columnar cactus used for its edible fruit occurring in natural forests, silviculturally managed in milpa agroforestry systems, and agriculturally managed in homegardens of the Tehuacán Valley, Mexico. We aimed at analyzing criteria of artificial selection and their consequences on phenotypic diversity and differentiation, as well as documenting management of propagules at landscape level and their possible contribution to gene flow among populations.

Methods

Semi-structured interviews were conducted to 83 households of the region to document perception of variation, criteria of artificial selection, and patterns of moving propagules among wild and managed populations. Morphological variation of trees from nine wild, silviculturally and agriculturally managed populations was analyzed for 37 characters through univariate and multivariate statistical methods. In addition, indexes of morphological diversity (MD) per population and phenotypic differentiation (PD) among populations were calculated using character states and frequencies.

Results

People recognized 15 pitaya varieties based on their pulp color, fruit size, form, flavor, and thorniness. On average, in wild populations we recorded one variety per population, in silviculturally managed populations 1.58 ± 0.77 varieties per parcel, and in agriculturally managed populations 2.19 ± 1.12 varieties per homegarden. Farmers select in favor of sweet flavor (71% of households interviewed) and pulp color (46%) mainly red, orange and yellow. Artificial selection is practiced in homegardens and 65% of people interviewed also do it in agroforestry systems. People obtain fruit and branches from different population types and move propagules from one another. Multivariate analyses showed morphological differentiation of wild and agriculturally managed populations, mainly due to differences in reproductive characters; however, the phenotypic differentiation indexes were relatively low among all populations studied. Morphological diversity of S. pruinosus (average MD = 0.600) is higher than in other columnar cacti species previously analyzed.

Conclusions

Artificial selection in favor of high quality fruit promotes morphological variation and divergence because of the continual replacement of plant material propagated and introduction of propagules from other villages and regions. This process is counteracted by high gene flow influenced by natural factors (pollinators and seed dispersers) but also by human management (movement of propagules among populations), all of which determines relatively low phenotypic differentiation among populations. Conservation of genetic resources of S. pruinosus should be based on the traditional forms of germplasm management by local people.     

Hat weaving withJipi, Carludovica Palmata (Cyclanthaceae) in the Yucatan Peninsula, Mexico

Weaving hats withjipi,Carludovica palmata (Cyclanthaceae) has built the local economy and cultural identity for the people of Becal, in the Yucatán Peninsula, Mexico. They obtain most material from cultivated sources, weave in man-made caves, and market the goods to commercial centers. BecauseJipi does not appear to deplete the soil, they do not need to clear more land for sustainable production. Although weaving traditionally served as the main source of income and social activity in Becal, interest in weaving is declining as the town modernizes. Although profits gained from weaving add to family earnings, because of the many hands through which the hat passes, this income remains low compared to the final selling prices. Thus, many who have the opportunity to pursue other careers are doing so. However, for rural communities, without other earning options, weaving may provide an economically and environmentally advantageous way to use the land.     

Wild Meat Use and Traditional Hunting Practices in a Rural Mayan Community of the Yucatan Peninsula,Mexico

Overexploitation of Neotropical ecosystems for wild meat constitutes a threat to biodiversity and might seriously affect local people who depend on wild animals as a primary food resource. To assess this problem at the local level, social use of wild animals was evaluated in a Mayan community of the Yucatan Peninsula. Over 8 months, peasant-hunters carried out a total of 175 hunting trips, gathering 253 animals of 12 species (mammals, birds and reptiles). Most preys (95%) were taken in 4 months (January–April) during the dry season and the main target species were white-tailed deer and iguana (jointly representing 59% of preys). During an 11-week period, total per capita wild meat consumption (182 kg; n = 14 families) was three times greater in nuclear than in extended families. The observed wild fauna use is a reflection of traditional knowledge and represents an important subsistence strategy for the local people.