两株聚球藻伴生细菌分离纯化与促生功能鉴定

【背景】蓝藻周围存在伴生细菌,伴生细菌与蓝藻具有复杂的作用关系。【目的】研究淡水聚球藻伴生细菌对聚球藻生长的影响。【方法】采用高通量测序分析聚球藻伴生细菌多样性;平板划线法纯化聚球藻伴生细菌,通过形态观察结合16S rRNA基因序列同源性比对,对其种属关系进行确定;通过聚球藻和不同浓度伴生细菌共培养测定其叶绿素a浓度,分析伴生细菌对聚球藻生长的影响;采用种子发芽试验验证伴生细菌促生功能。【结果】淡水聚球藻伴生细菌优势菌属为产卟啉杆菌属(Porphyrobacter)、根瘤菌属(Rhizobium)、水单胞菌属(Aquimonas)和中慢生根瘤菌属(Mesorhizobium),从聚球藻分离获得了两株伴生细菌JQ1和JQ2,基于16S rRNA基因序列鉴定其分别属于Rhizobium和Peribacillus,通过在聚球藻与不同浓度伴生细菌共培养及水稻发芽试验验证,证明伴生细菌JQ1和JQ2在菌藻比例分别为5:1和15:1时具有促生作用,都对增强秧苗素质和根系发育有一定影响但JQ2与JQ1相比能显著提高水稻种子的发芽率。【结论】淡水聚球藻伴生细菌JQ1和JQ2在适宜的浓度均可显著促进聚球...     

Taxonomic revision of the Tuberculatus quercicola group (Hemiptera: Aphididae: Drepanosiphinae), myrmecophilous aphids associated with Quercus species,based on morphometric and molecular phylogenetic studies

In this paper, we revised the taxonomy of the Tuberculatus quercicola group, myrmecophilous drepanosiphine aphids that are associated with Quercus dentata and Q. crispula in Japan, based on morphometry and molecular phylogeny. This species group has been recognized as T. quercicola with some junior synonyms. Morphometric analysis of 11 morphological characters divided the group into three clusters: (i) the Q. crispula‐associated population; (ii) the central Hokkaido group of the Q. dentata‐associated population; and (iii) the eastern Hokkaido group of the Q. dentata‐associated population. Most parsimony and maximum likelihood analyses of the mitochondrial cytochrome oxidase subunit I COI gene indicated that samples of the T. quercicola group are separated, with high bootstrap supports, into two monophyletic groups that are associated with either Q. dentata or Q. crispula. However, no genetic differentiation was detected between the central Hokkaido group and the eastern Hokkaido group of the Q. dentata‐associated population. These results led us to conclude that populations associated with Q. dentata are genetically and morphologically distinct from those associated with Q. crispula, and thus they are in a full specific status. On the other hand, we treated the two local groups of the Q. dentata‐associated population as local races based on morphology. We formally redescribed the Q. crispula‐associated and Q. dentata‐associated populations under the names T. quercicola and T. macrotuberculatus stat. rev., respectively.     

Differences in bacterial diversity of host-associated populations of Phylloxera notabilis Pergande (Hemiptera: Phylloxeridae) in pecan and water hickory

Host‐associated differentiation (HAD) is the presence of genetically divergent, host‐associated populations. It has been suggested that microbial symbionts of insect herbivores may play a role in HAD by allowing their insect hosts to use different plant species. The objective of this study was to document if host‐associated populations of Phylloxera notabilis Pergande (Hemiptera: Phylloxeridae) in pecan and water hickory corresponded with differences in the composition of their associated bacteria. To test this hypothesis, we characterized the symbionts present in P. notabilis associated with these two tree species through metagenomic analyses using 454 sequencing. Differences in bacterial diversity were found between P. notabilis populations associated with pecan and water hickory. The bacteria, Pantoea agglomerans and Serratia marcescens, were absent in the P. notabilis water hickory population, whereas both species accounted for more than 69.72% of bacterial abundance in the pecan population.     

Bacterial diversity associated with the Caribbean tunicate <Emphasis Type="Italic">Ecteinascidia turbinata</Emphasis>

The Caribbean tunicate, Ecteinascidia turbinata produces the anti-cancer agent ET-743 that could well be a metabolite of an associated bacterial strain. This current study aims at the analysis of bacteria that are persistently and specifically associated with this invertebrate. Utilizing techniques such as denaturing gradient gel electrophoresis, DNA sequencing and phylogenetic analysis of bacteria from E. turbinata collected from different locations in the Caribbean Sea, we report here the identification of five possible persistently associated bacteria. Of these, only one organism, Candidatus Endoecteinascidia frumentensis, was found specifically associated to E. turbinata from the Caribbean and has also been found to be associated with E. turbinata from the Mediterranean. These experiments suggest that assessment of bacterial diversity associated with invertebrates from different geographical sites might be an effective way of identifying persistently and specifically associated bacteria.     

Inhibition of Ageratina riparia (Asteraceae) by native Australian flora and fauna

We investigated the influence of native flora and fauna on the establishment and persistence of the exotic weed Ageratina riparia (Asteraceae) in disturbed and regenerating rainforests on the Springbrook plateau of south‐eastern Queensland. The height and ground cover of A. riparia was positively associated with light availability beneath the rainforest canopy and negatively associated with forest leaf litter biomass. Regenerating rainforest with the associated increases in litter and decrease in light availability could therefore inhibit the establishment and density of A. riparia. The red‐necked pademelon, Thylogale thetis, browsed extensively on A. riparia, but the pattern of browsing was not associated with light availability, forest leaf litter biomass or density of A. riparia. Browsing and incidental damage by T. thetis breaks up the broad stands of A. riparia. The physical damage caused by T. thetis, and the inhibition to establishment and density of A. riparia by native plant species, combine to reduce the environmental threat associated with A. riparia.     

Chinese white truffles shape the ectomycorrhizal microbial communities of Corylus avellana

Here, we investigated the influence of Chinese white truffle (Tuber panzhihuanense) symbioses on the microbial communities associated with Corylus avellana during the early development stage of symbiosis. The microbial communities associated with ectomycorrhizae, and associated with roots without T. panzhihuanense colonization, were determined via high-throughput sequencing of bacterial 16S rRNA genes and fungal ITS genes. Microbial community diversity was higher in the communities associated with the ectomycorrhizae than in the control treatment. Further, bacterial and fungal community structures were different in samples containing T. panzhihuanense in association with C. avellana compared to the control samples. In particular, the bacterial genera Rhizobium, Pedomicrobium, and Herbiconiux were more abundant in the ectomycorrhizae, in addition to the fungal genus Monographella. Moreover, there were clear differences in some physicochemical properties among the rhizosphere soils of the two treatments. Statistical analyses indicated that soil properties including exchangeable magnesium and exchangeable calcium prominently influenced microbial community structure. Lastly, inference of bacterial metabolic functions indicated that sugar and protein metabolism functions were significantly more enriched in the communities associated with the ectomycorrhizae from C. avellana mycorrhized with T. panzhihuanense compared to communities from roots of cultivated C. avellana without T. panzhihuanense. Taken together, these results highlight the interactions among ectomycorrhizal fungi, soil properties, and microbial communities that are associated with host plants and further our understanding of the ecology and cultivation of the economically important T. panzhihuanense truffles.

     

Proteomic analysis and abrogated expression of O‐GlcNAcylated proteins associated with primary breast cancer

O‐GlcNAcylation is a dynamic PTM of nuclear and cytoplasmic proteins, regulated by O‐GlcNAc transferase (OGT) and O‐GlcNAcase, which catalyze the addition and removal of O‐GlcNAc, respectively. This modification is associated with glucose metabolism, which plays important roles in many diseases including cancer. Although emerging evidence reveals that some tumor‐associated proteins are O‐GlcNAc modified, the total O‐GlcNAcylation in cancer is still largely unexplored. Here, we demonstrate that O‐GlcNAcylation was increased in primary breast malignant tumors, not in benign tumors and that this augmentation was associated with increased expression of OGT level. Using 2D O‐GlcNAc immnoblotting and LC‐MS/MS analysis, we successfully identified 29 proteins, with seven being uniquely O‐GlcNAcylated or associated with O‐GlcNAcylation in cancer. Of these identified proteins, some were related to the Warburg effect, including metabolic enzymes, proteins involved in stress responses and biosynthesis. In addition, proteins associated with RNA metabolism, gene expression, and cytoskeleton were highly O‐GlcNAcylated or associated with O‐GlcNAcylation. Moreover, OGT knockdown showed that decreasing O‐GlcNAcylation was related to inhibition of the anchorage‐independent growth in vitro. These data indicate that aberrant protein O‐GlcNAcylation is associated with breast cancer. Abnormal modification of these O‐GlcNAc‐modified proteins might be one of the vital malignant characteristics of cancer.     

Vriesea friburgensis: A natural trap or a nurse plant in coastal sand dunes?

Positive interactions between plants play a fundamental role in environments with extreme conditions, such as coastal sand dunes, where the establishment of many species is limited by high temperature, and low availability of water and nutrients in the soil. The ability to store water and enrich the soil with nutrients characterizes bromeliads as potential nurse plants for other species. This study aimed to analyze the potential of the bromeliad Vriesea friburgensis to act as a nurse plant, and to compare this interaction in coastal dunes in herbaceous versus scrub vegetation. The study was performed on Santa Catarina Island in Brazil. Juveniles of other species associated with V. friburgensis were collected within and under bromeliad tanks and on adjacent plots beside each bromeliad. The abundance, species richness and height of juveniles were recorded. We found that abundance and richness of Vf‐associated juveniles were lower than those Vf‐not associated, in herbaceous vegetation (negative interaction). However, the height of some shrubs species, like Eupatorium casarettoi and Tibouchina urvilleana, was greater when Vf‐associated (positive interaction). In scrub vegetation, the abundance and richness of juveniles were not significantly affected by V. friburgensis presence (neutral interaction). However, the height of some shrubs and trees species, like Clusia criuva, Eugenia catharinae, Myrsine parvifolia and Ocotea pulchella, was greater when Vf‐associated. Species composition associated with V. friburgensis differed from the assemblage in adjacent plots, indicating that some species interact more with nurse plants, whereas others fail to develop when associated with this bromeliad; the difference between groups in species composition was less evident in scrub vegetation areas. Clusia criuva was considered an indicator species for Vf‐associated juveniles in both vegetation types. Despite the fact that these tank bromeliads do not function as nurse plants for some species, there are others that seem to be favoured by this interaction.     

Genetic markers on BTA14 predictive for residual feed intake in beef steers and their effects on carcass and meat quality traits

With the high cost of feed for animal production, genetic selection for animals that metabolize feed more efficiently could result in substantial cost savings for cattle producers. The purpose of this study was to identify DNA markers predictive for differences among cattle for traits associated with feed efficiency. Crossbred steers were fed a high‐corn diet for 140 days and average daily feed intake (ADFI), average daily gain (ADG), and residual feed intake (RFI) phenotypes were obtained. A region on chromosome 14 was previously associated with RFI in this population of animals. To develop markers with the highest utility for predicting an animal's genetic potential for RFI, we genotyped additional markers within this chromosomal region. These polymorphisms were genotyped on the same animals (n = 1066) and tested for association with ADFI, ADG and RFI. Six markers within this region were associated with RFI (P ≤ 0.05). After conservative correction for multiple testing, one marker at 25.09 Mb remained significant (P = 0.02) and is responsible for 3.6% of the RFI phenotypic variation in this population of animals. Several of these markers were also significant for ADG, although none were significant after correction. Marker alleles with positive effects on ADG corresponded to lower RFI, suggesting an effect increasing growth without increasing feed intake. All markers were also assessed for their effects on meat quality and carcass traits. All of the markers associated with RFI were associated with adjusted fat thickness (AFT, P ≤ 0.009) and three were also associated with hot carcass weight (HCW, P ≤ 0.003). Marker alleles associated with lower RFI were also associated with reduced AFT, and if they were associated for HCW, the effect was an increase in weight. These markers may be useful as prediction tools for animals that utilize feed more efficiently; however, validation with additional populations of cattle is required.     

Genetic markers that influence feed efficiency phenotypes also affect cattle temperament as measured by flight speed

Flight speed is a predictive indicator of cattle temperament and is associated with feed efficiency phenotypes. Genetic markers associated with both traits may assist with selection of calmer animals with improved economic value. A preliminary genome‐wide association study determined chromosomal regions on BTA9, and 17 were associated with flight speed. The genes quaking (QKI), glutamate receptor, ionotropic, AMPA 2 (GRIA2) and glycine receptor β (GLRB) were identified in these regions as potential functional candidates. Beef steers (n = 1057) were genotyped with SNPs located within and flanking these genes. One SNP located near QKI and one near GRIA2 were nominally associated with flight speed (P ≤ 0.05) although neither was significant after Bonferroni correction. Several studies have shown a correlation between flight speed and feed intake or gain; therefore, we also analyzed SNPs on BTA6:38–39 Mb known to be associated with average daily gain (ADG) and average daily feed intake (ADFI) for association with flight speed. Several SNPs on BTA6 were associated with flight speed (P ≤ 0.005), and three were significant after Bonferroni correction. These results suggest that the genes tested are unlikely to contribute to flight speed variation for our cattle population, but SNPs on BTA6 associated with ADG and ADFI may influence temperament. Use of these markers to select for economically important feed efficiency phenotypes may produce cattle with more desirable temperaments.     

<Emphasis Type="Italic">ANKH</Emphasis>variants associated with ankylosing spondylitis: gender differences

The ank (progressive ankylosis) mutant mouse, which has a nonsense mutation in exon 12 of the inorganic pyrophosphate regulator gene (ank), exhibits aberrant joint ankylosis similar to human ankylosing spondylitis (AS). We previously performed family-based association analyses of 124 Caucasian AS families and showed that novel genetic markers in the 5' flanking region of ANKH (the human homolog of the murine ank gene) are modestly associated with AS. The objective of the present study was to conduct a more extensive evaluation of ANKH variants that are significantly associated with AS and to determine whether the association is gender specific. We genotyped 201 multiplex AS families with nine ANKH intragenetic and two flanking microsatellite markers, and performed family-based association analyses. We showed that ANKH variants located in two different regions of the ANKH gene were associated with AS. Results of haplotype analyses indicated that, after Bonferroni correction, the haplotype combination of rs26307 [C] and rs27356 [C] is significantly associated with AS in men (recessive/dominant model; P = 0.004), and the haplotype combination of rs28006 [C] and rs25957 [C] is significantly associated with AS in women (recessive/dominant model; P = 0.004). A test of interaction identified rs26307 (i.e. the region that was associated in men with AS) as showing a difference in the strength of the association by gender. The region associated with AS in women only showed significance in the test of interaction among the subset of families with affected individuals of both genders. These findings support the concept that ANKH plays a role in genetic susceptibility to AS and reveals a gender–genotype specificity in this interaction.     

Asterocherids (Copepoda; Siphonostomatoida) associated with invertebrates from California Reefs: Abrolhos (Brazil)

Four new asterocherid siphonostomatoid copepods are described, and several new geographical and host records are provided from California Reefs off the coast of Brazil. Acontiophorus monanchorae sp. nov. and Scottocheres youngi sp. nov. were both found associated with the sponge Monanchora sp. Asterocheres aplysinus sp. nov. and Asterocheres spongus sp. nov. were each associated with three genera of sponges. Asterocheres crenulatus previously recorded from the region, was associated with the sponge Xestospongia sp. Asterocheres paraboecki was recorded for the first time in the region. Asterocheres spinopaulus, previously reported from sponges, was found associated with bryozoans and cnidarians. Cletopontius titanus and Orecturus bahiensis were again recorded from the region and from sponges. Scottocheres laubieri, previously known from the Mediterranean Sea, was recorded for the first time in Brazilian waters, associated with the sponge Aplysina sp.     

The −1030/−862-linked TNF promoter single-nucleotide polymorphisms are associated with the inability to control HIV-1 viremia

Control of HIV-1 viremia and progression to AIDS has been associated with specific HLA genes. The tumor necrosis factor (TNF) and the non-classical major histocompatibility (MHC) class I chain-related A (MICA) genes are located in the genomic segment between the HLA class I and II genes and variants of both genes have been identified. We thus analyzed TNF promoter and MICA variants in a well-characterized group of HIV-1 infected individuals with different abilities to control HIV-1 viremia. In our cohort, the –1030/–862-linked TNF promoter single-nucleotide polymorphisms (SNPs), but not MICA variants, are significantly associated with lack of control of HIV-1 viremia (P=0.03). This association is independent of those HLA-B35 alleles associated with HIV-1 disease progression with which the –862 TNF SNP has previously been independently associated. Thus, non-randomly associated genes near the TNF locus are likely involved in control of HIV-1 viremia.     

Molecular phylogeny and evolution of host-plant use in conifer seed chalcids in the genus Megastigmus (Hymenoptera: Torymidae)

Abstract. Phylogenetic relationships amongst Megastigmus species (Chalcidoidea: Torymidae) associated with conifer seeds were inferred from DNA sequence data. Twenty‐nine species of seed chalcids were analysed using two different genes, cytochrome b (mitochondrial DNA) and the D2 domain of the 28S ribosomal DNA. Maximum‐parsimony and maximum‐likelihood analyses showed that taxa formed two monophyletic groups, one clade comprising all species associated with Cupressaceae and Taxodiaceae hosts with the exception of Chamaecyparis, and the other clade composed of species associated with Pinaceae. Species infesting Cupressaceae and Taxodiaceae seemed to be specialized to particular host genera or even to be species specific, which was consistent with a taxonomic radiation following initial host adaptation. By contrast, Megastigmus species associated with Pinaceae appeared capable of shifting onto different congeneric species or even onto a new host genus, with their evolution apparently less constrained by plant association. We hypothesized that the Megastigmus group associated with Pinaceae may have a much higher invasive potential than that related to Cupressaceae. The study also confirmed the presence of invasive Nearctic species in the Palaearctic, and demonstrated the existence of a cryptic species complex.     

Association of single nucleotide polymorphisms in the ANKRA2 and CD180 genes with bovine respiratory disease and presence of Mycobacterium avium subsp. paratuberculosis(1)

The objective was to determine whether single nucleotide polymorphisms (SNPs) in the ANKRA2 and CD180 genes are associated with incidence of bovine respiratory disease (BRD) and presence of Mycobacterium avium subsp. paratuberculosis (MAP) in cattle. Two independent populations were used. The first population (BRD‐affected; N = 90) was composed of 31 half‐sib progeny, from a Brahman × Angus sire, that were treated for BRD. Untreated offspring from the sire were selected to serve as controls. The second population (MAP‐infected) of 330 animals of unknown parentage was evaluated for the presence of MAP in ileocecal lymph node and classified as positive or negative. Markers in both genes were assessed for association in these two populations. In the BRD‐affected population, five SNPs in the ANKRA2 gene were significantly associated (P < 0.05), and two SNPs were highly associated (P < 0.01) with incidence of BRD. In addition, two SNPs in the CD180 gene were found to be associated with this trait. In the MAP‐infected population, one SNP in the ANKRA2 gene was significantly associated (P < 0.05) with the presence or absence of MAP, and a SNP in the CD180 gene was highly associated (P < 0.01) with the trait. Haplotypes, using significant markers, showed a positive association with both incidence of BRD (P = 0.0001) and with the presence of MAP (P = 0.0032). Markers in the ANKRA2 and CD180 genes are associated with the ability of the animal to cope with pathogens.     

The effect of caffeine,different fixation regimes and low temperature on microtubules in the cells of higher plants

Caffeine, (1:3:7-tri-methyl-xanthine), either as a prefixation treatment or included with glutaralde-hyde as the primary fixative, destroys or disorganises the microtubules associated with the formation of secondary walls in fibres from the flowering stem of the grass Lolium temulentum L. There is no observable effect of caffeine treatment on the microtubules associated with primary wall formation in collenchyma and young fibres from L. temulentum or in root cap cells of Zea mays L. and Phaseolus vulgaris L. The microtubules associated with primary wall formation are destroyed by cold treatment but not those associated with secondary wall formation. Tannic acid included in the fixative shows the microtubules associated with secondary wall formation in fibres of L. temulentum to be composed of 13 subunits. Treatment with lanthanum hydroxide does not stain the core or the halo of the microtubules.Abbreviation PIPES Piperazine N-N- bis 2 ethanol sulphonic acid The Grassland Research Institute is financed through the Agricultural Research Council     

Different strategies of energy storage in cultured and freshly isolated Symbiodinium sp.

The endosymbiotic relationship between cnidarians and Symbiodinium is critical for the survival of coral reefs. In this study, we developed a protocol to rapidly and freshly separate Symbiodinium from corals and sea anemones. Furthermore, we compared these freshly‐isolated Symbiodinium with cultured Symbiodinium to investigate host and Symbiodinium interaction. Clade B Symbiodinium had higher starch content and lower lipid content than those of clades C and D in both freshly isolated and cultured forms. Clade C had the highest lipid content, particularly when associated with corals. Moreover, the coral‐associated Symbiodinium had higher protein content than did cultured and sea anemone‐associated Symbiodinium. Regarding fatty acid composition, cultured Symbiodinium and clades B, C, and D shared similar patterns, whereas sea anemone‐associated Symbiodinium had a distinct pattern compared coral‐associated Symbiodinium. Specifically, the levels of monounsaturated fatty acids were lower than those of the saturated fatty acids, and the level of polyunsaturated fatty acids (PUFAs) were the highest in all examined Symbiodinium. Furthermore, PUFAs levels were higher in coral‐associated Symbiodinium than in cultured Symbiodinium. These results altogether indicated that different Symbiodinium clades used different energy storage strategies, which might be modified by hosts.     

Host race formation in the leaf-mining moth Acrocercops transecta (Lepidoptera: Gracillariidae)

Genetic differentiation in ecological traits plays an important role in the reproductive isolation of phytophagous insects. The present study aims to elucidate the genetic changes involved during the process of host shifts, by combining analyses for (1) host adaptations, (2) pre‐ and postmating isolation, and (3) phylogeney among populations, using a leaf‐mining moth, Acrocercops transecta. This species is associated with Juglans ailanthifolia and Lyonia ovalifolia. Transplantation of the larvae demonstrated that the Juglans‐associated population completely failed to survive on Lyonia, whereas the Lyonia‐associated population survived on Juglans as well as on Lyonia. Females of respective host‐associated populations oviposited on their natal host plant only. An mtDNA‐based phylogeny clearly separated the Lyonia‐associated population from the Juglandaceae‐associated population, and indicated that the Lyonia‐associated population once evolved from the Juglandaceae‐associated population. These results indicate that the processes of host shifting from juglandaceous species to Lyonia involved genetic changes both in larval ability to use host plants and in host preference of females. The derived Lyonia‐associated population has retained the potential to assimilate the ancestral host, Juglandaceae. Mating between the two host‐associated populations was successful for both directions of crossing, and there were no significant differences in egg hatchability between hybrids and control crosses. No adults emerged when the F₁ hybrid larvae were maintained on Lyonia; however, on Juglans the F₁ hybrid larvae grew to adulthood as well as in the control, suggesting a lack of genomic incompatibilities between the two host‐associated populations. In conclusion, the results showed that the two host‐associated populations are host races that are partially reproductively isolated, and that the differences in performance and preference function as strong barriers against gene flow between the host races. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93 , 135–145.     

Association of vitamin D receptor gene polymorphism with the risk of lung cancer: a meta-analysis

Abstract

Relationship between vitamin D receptor (VDR) gene polymorphism and the risk of lung cancer from the published reports are still conflicting. This study was conducted to evaluate the relationship between VDR TaqI (rs731236), BsmI (rs1544410) and ApaI (rs7975232) gene polymorphism and the risk of lung cancer using meta-analysis method. The association studies were identified from PubMed and Cochrane Library on 1 December 2013, and eligible investigations were included and synthesized using meta-analysis method. Six reports were recruited into this meta-analysis for the association of VDR gene polymorphism with lung cancer susceptibility. In the meta-analysis for ApaI gene polymorphism, AA genotype was associated with the risk of lung cancer in Asians. In the meta-analysis for BsmI gene polymorphism, B allele, BB genotype and bb genotype were associated with lung cancer in Asians, and B allele bb genotype were associated with lung cancer risk in overall populations; furthermore, bb genotype was associated with lung cancer risk in Caucasians. In the meta-analysis for TaqI gene polymorphism, t allele and TT genotype were associated with lung cancer in overall populations and in Caucasians. In conclusion, B allele bb genotype t allele and TT genotype were associated with lung cancer risk in overall populations. AA genotype, B allele, BB genotype and bb genotype were associated with the risk of lung cancer in Asians. Furthermore, bb genotype t allele and TT genotype was associated with lung cancer risk in Caucasians. However, more studies should be conducted to confirm it.     

Septic tanks as larval habitats for the mosquitoes Aedes aegypti and Culex quinquefasciatus in Playa‐Playita,Puerto Rico

Adult Aedes aegypti (Linnaeus) (Diptera: Culicidae) were previously recovered from emergence traps on septic tanks in southeastern Puerto Rico. In this study we quantified immature mosquito abundance and its relationship with structural variables of the septic tanks and chemical properties of the water containing raw sewage. A miniaturized floating funnel trap was used to sample 89 septic tanks for larvae in the Puerto Rican community of Playa‐Playita. Aedes aegypti larvae were recovered from 18% of the sampled tanks (10.3 larvae per septic tank per day). Larval presence was positively associated with cracking of the septic tank walls and uncovered access ports. Larval abundance was positively associated with cracking of the septic tank walls and larger tank surface areas, and inversely associated with the total dissolved solids (TDS). Culex quinquefasciatus (Say) larvae were also recovered from 74% of the septic tanks (129.6 larvae per septic tank per day). Larval presence was negatively associated with TDS in the water and larval abundance was positively associated with cracking of the septic tank walls. A screened, plastic emergence trap was used to sample 93 septic tanks within the community for Ae. aegypti and Cx. quinquefasciatus adults. Aedes aegypti adults were recovered from 49% of the sampled tanks (8.7 adults per septic tank per day) and Cx. quinquefasciatus adults were recovered from 97% of the sampled tanks (155.5 adults per septic tank per day). Aedes aegypti adult presence was positively associated with cracking, uncapped openings and septic water pH. The Ae. aegypti adult counts were positively associated with cracking and inversely associated with TDS and conductivity. This study marks the first published record of the recovery of Ae. aegypti larvae from holding tanks containing raw sewage in the Caribbean region. Our study indicates that Ae. aegypti larvae are present in sewage water and that septic tanks have at least the potential to maintain dengue transmission during the dry season.