Ecotoxicological assessment of sanitary sewer overflows and rainfall dynamics offers insights into conditions for potential adverse ecological outcomes.

Sewer overflows are an environmental concern due to their potential to introduce contaminants that can adversely affect downstream aquatic ecosystems. As these overflows can occur during rainfall events, the influence of rainwater ingress from inflow and infiltration on raw untreated wastewater (influent) within the sewer is a critical factor influencing the dilution and toxicity of the contaminants. The Vineyard sewer carrier in the greater city of Sydney, Australia, was selected for an ecotoxicological investigation of a sanitary (separate to stormwater) sewerage system and a wet-weather overflow (WWO). Three influent samples were collected representing dry-weather (DW), intermediate wet-weather (IWW) and wet-weather (WW). In addition, a receiving water sample was also collected downstream in Vineyard Creek (WW-DS) coinciding with a WWO. We employed direct toxicity assessment (DTA) and toxicity identification evaluation (TIE) approaches to gain comprehensive insights into the nature and magnitude of the impact on influent from rainwater ingress into the sewer. Three standard ecotoxicological model species, a microalga, Chlorella vulgaris, the water flea, Ceriodaphnia dubia and the midge larva, Chironomus tepperi were used for both acute and chronic tests. The study revealed variable toxicity responses, with the sample of influent collected in wet-weather displaying lower toxicity compared to the dry-weather sample of influent. Ammonia, and metals, were identified in dry weather as contributors to the observed toxicity, however, this risk was alleviated through rainwater ingress in wet-weather with further dilution within the receiving water. Based on toxicity data, dilutions of influent to minimise effects on C. vulgaris and C. dubia ranged from 1 in 12 in DW to 1 in 2.8 in WW, and further diminished in the receiving water to 1 in 1.8. The successful application of ecotoxicological approaches enabled the assessment of cumulative effects of contaminants in influent, offering valuable insights into sanitary sewer system under rainwater ingress.

The CpxAR signaling system confers a fitness advantage for flea gut colonization by the plague bacillus.

The adaptation of Yersinia pestis, the flea-borne plague agent, to fluctuating environmental conditions is essential for the successful colonization of the flea vector. A previous comparative transcriptomic analysis showed that the Cpx pathway of Y. pestis is up-regulated in infected fleas. The CpxAR two-component system is a component of the envelope stress response and is critical for maintaining the integrity of the cell. Here, a phenotypic screening revealed a survival defect of the cpxAR mutant to oxidative stress and copper. The measured copper concentration in the digestive tract contents of fed fleas increased fourfold during the digestive process. By direct analysis of phosphorylation of CpxR by a Phos-Tag gel approach, we demonstrated that biologically relevant concentrations of copper triggered the system. Then, a competitive challenge highlighted the role of the CpxAR system in bacterial fitness during flea infection. Lastly, an in vitro sequential exposure to copper and then H2O2 to mimic the flea suggests a model in which, within the insect digestive tract, the CpxAR system would be triggered by copper, establishing an oxidative stress response. IMPORTANCE: The bacterium Yersinia pestis is the agent of flea-borne plague. Our knowledge of the mechanisms used by the plague bacillus to infect the flea vector is limited. The up-regulation of the envelope stress response under the control of the Cpx signaling pathway was previously shown in a transcriptomic study. Here, our in vivo and in vitro approaches suggest a model in which Y. pestis uses the CpxAR phosphorelay system to sense and respond to the copper present in the flea gut, thereby optimizing the flea gut colonization. In other words, the system is essential for bacterial fitness in the flea.

Insecticidal and Repellent Activity of Essential Oils from Copaifera reticulata, Citrus paradisi, Lavandula hybrida and Salvia sclarea Against Immature and Adult Stages of Ctenocephalides felis felis.

PURPOSE: The flea Ctenocephalides felis (Siphonaptera: Pulicidae), parasitizes dogs and cats globally, acting as a vector for various pathogens affecting both animals and humans. Growing interest in environmentally friendly, plant-based products prompted this study. The aim of the study was to determine the chemical composition of essential oils (EOs) from Copaifera reticulata, Citrus paradisi, Lavandula hybrida and Salvia sclarea, assessing their insecticidal and repellent properties, determining lethal concentrations (LC50 and LC90), and evaluating residual efficacy in vitro against Ctenocephalides felis felis. METHODS: Gas Chromatography with Flame Ionization Detector analyzed EO composition. In vitro tests involved preparing EO solutions at various concentrations. Ten specimens from each life stage (egg, larva, pupa, adult) were used for insecticidal activity assessment. Adulticidal activity was assessed using 10 cm2 filter paper strip, each treated with 0.200 mL of the test solution. Immature stages activities were evaluated using 23.76 cm2 discs of the same filter paper, each treated with 0.470 mL of the test solution. Mortality percentage was calculated using (number of dead insects × 100) / number of incubated insects. Probit analysis calculated LC50 values with a 95% confidence interval. RESULTS: Major EO constituents were ß-caryophyllene (EOCR), linalool (EOLH), linalyl acetate (EOSS), and limonene (EOCP). LC50 values were obtained for all stages except for the essential oil of C. paradisi. All oils showed repellent activity at 800 µg/cm2. OECR exhibited greater residual efficacy. CONCLUSION: Each EO demonstrated superior insecticidal activity against specific C. felis felis stages.

Physiological and transcriptional changes associated with obligate aestivation in the cabbage stem flea beetle (Psylliodes chrysocephala).

Aestivation is a form of seasonal dormancy observed in various insect species, usually coinciding with the summer season. The cabbage stem flea beetle, Psylliodes chrysocephala (Coleoptera: Chrysomelidae), is a key pest of oilseed rape that obligatorily aestivates as adult in late summer. Since the physiological and transcriptional processes linked to aestivation in P. chrysocephala are still little understood, we analyzed relevant physiological parameters and performed RNA-seq analyses on laboratory-reared beetles in their pre-aestivation, aestivation, and post-aestivation stages. We found that the beetles reached aestivation at 15 days post-eclosion, showing strongly reduced metabolic activity, with less than 50% CO2 production, compared to pre-aestivating individuals. Under constant laboratory conditions, the beetles aestivated for about 25 days. Female beetles reached reproductive maturity at a median of 52 days post-eclosion. Furthermore, aestivating beetles had significantly reduced carbohydrate reserves and increased lipid reserves compared with pre-aestivating beetles, indicating that aestivation is associated with drastic changes in energy metabolism. Aestivating beetles contained 30% less water and their survival rates under high-temperature conditions (30 °C) were 40% higher compared to pre-aestivating beetles. RNA-seq studies showed that, in particular, gene ontology terms related to carbohydrate and lipid metabolism, digestion, and mitochondrial activity were enriched, with clear differences in transcript abundance between beetles in aestivation compared to pre- or post-aestivation. Specifically, mitochondrial transcripts, such as respiratory chain I subunits, and digestion-related transcripts, such as trypsin, were less abundant during aestivation, which supports the idea that aestivation is associated with decreased metabolic activity. This study represents the first exploration of the transcriptomic and physiological processes linked to aestivation in P. chrysocephala.

Bartonella rochalimae in a flea collected from a Mephitis macroura in Sonora Mexico.

PURPOSE: At least thirty species of wild carnivores have been recorded harboring Bartonella, and one of the most common pathogenic species infecting them is Bartonella rochalimae, which can cause endocarditis in humans and dogs. This bacterium can infect various mammals including wild carnivores, as well as ectoparasitic vectors such as fleas and ticks. Here we report the presence of B. rochalimae, in a Pulex simulans flea collected from a Mephitis macroura skunk in the municipality of Santa Cruz in Sonora, Mexico. METHODS: Fleas were collected from a M. macroura in Sonora, Mexico, in October 2019. They were identified to species level and subsequently tested for the presence of Bartonella using molecular tools including conventional PCR, sequencing, and phylogenetic analysis. RESULTS: A total of 10 P. simulans fleas (one male, nine females) were collected from the M. macroura skunk. The PCR and phylogenetic analysis indicated a prevalence of 10% (1/10) and a sequence clustered with the clade of B. rochalimae. CONCLUSIONS: We confirmed the presence of B. rochalimae in a P. simulans flea collected from a M. macroura skunk in the area of Santa Cruz, Sonora, Mexico. Based on our results and previous studies in northern Mexico, which are consistent, it is necessary to continue monitoring Bartonella in M. macroura skunks and their fleas, since they could be important reservoirs of this bacterium in northern Mexico.

Acute and chronic effects of the antifouling booster biocide Irgarol 1051 on the water flea Moina macrocopa revealed by multi-biomarker determination.

Irgarol 1051 is an herbicide extensively utilized in antifouling paint due to its ability to inhibit photosynthesis. Irgarol and its photodegradation products are highly persistent in waters and sediments, although they are present in low concentrations. However, our understanding of the harmful effects of Irgarol on non-target organisms remains limited. In this study, we assessed the effects of acute (24 h) and chronic (14 days across three generations) exposure to different concentrations (including the 1/10 NOEC, NOEC, and 1/10 LC50 calculated from the 24-h acute toxicity test) of Irgarol using the water flea Moina macrocopa. Acute exposure to 1/10 LC50 significantly decreased survival, feeding rate, thoracic limb activity, heart rate, and acetylcholinesterase activity. Elevated levels of intracellular reactive oxygen species and malondialdehyde, along with a significant increase in catalase and superoxide dismutase activity, suggested the induction of oxidative stress in response to 1/10 LC50. An initial boost in glutathione level and the enzymatic activities of glutathione peroxidase and glutathione reductase, followed by a plunge, implies some compromise in the antioxidant defense system. Upon chronic exposure to the NOEC value, both generations F1 and F2 displayed a significant decrease in survival rate, body length, number of neonates per brood, and delayed sexual maturation, suggesting maternal transfer of potential damage through generations. Taken together, Irgarol induced acute toxicity through physiological and cholinergic damage, accompanied by the induction of oxidative stress, in the water flea. Even its sub-lethal concentrations can induce detrimental effects across generations when consistently exposed.

Palearctic flea beetle and pest of hops and Cannabis, Psylliodesattenuata (Coleoptera, Chrysomelidae, Galerucinae), new to North America.

Background: The univoltine leaf beetle Psylliodesattenuata (Koch, 1803) is a pest of Cannabis and Humulus (Cannabaceae) and native to the Palaearctic Region, known from eastern Asia to western Europe. New information: First North American records are presented for P.attenuata from Canada: Ontario and Québec. Adult beetle feeding damage to hops Humuluslupulus L. (Cannabacaea) plants is recorded from Québec. Diagnostic information is presented to distinguish P.attenuata from other North American Chrysomelidae and a preliminary assessment of its potential to spread in North America is presented. While our climate analysis is limited by a lack of data, it appears P.attenuata is physiologically capable of persisting throughout the range of Humulus in North America.The United States of America and Canada are now known to be home to 71 or more species of adventive Chrysomelidae.

Flea-Borne Rickettsioses and Scrub Typhus in Patients with Suspected Arbovirus Infection in Bangkok, Thailand.

Background: In urban Thailand, arboviral infections dominate diagnoses of acute undifferentiated fevers (AUFs) owing to their well-defined epidemiology and characteristic clinical presentations. However, rickettsial diseases, also endemic in this setting, remain under-recognized owing to challenges in early detection. Objective: This study aimed to identify potential rickettsial infections among patients with AUF in Bangkok and vicinity utilizing leftover nucleic acid extracted from serum samples from patients initially suspected of but negative for arbovirus infections. Materials and Methods: A total of 609 nucleic acid samples were screened for rickettsial bacteria using real-time PCR, targeting the 17-kDa common antigen gene of Rickettsia spp. and the 47-kDa gene of Orientia tsutsugamushi. Results: Nine samples were positive for Rickettsia spp. and two were positive for O. tsutsugamushi. DNA sequence and phylogenetic analyses based on partial 17-kDa antigen and citrate synthase (gltA) genes identified the Rickettsia-positive samples as R. typhi in eight cases and R. felis in one case. Analysis of the 56-kDa type-specific antigen gene identified the two O. tsutsugamushi isolates as Gilliam-related genotypes. Although rickettsial diseases typically present with mild symptoms, two patients with R. typhi infection (murine typhus) developed respiratory distress syndrome, highlighting the potential for rare but serious complications. Conclusion: This study underscores the critical importance of differential diagnosis and prompt, effective intervention to prevent complications in suspected cases.

Bartonella, Blechomonas and Trypanosoma in fleas from the long-tailed ground squirrel (Spermophilus undulatus) in northwestern China.

Fleas are known to be vectors for a variety of pathogens in veterinary medicine. However, no information is available on the presence of Bartonella and Trypanosomatidae in fleas of the long-tailed ground squirrel (LTGR, Spermophilus undulatus). The present study shows detection of these pathogens in LTGR fleas. During 2022-2023, a total of 396 fleas were collected from 91 LTGRs in 4 alpine regions of Xinjiang Uygur Autonomous Region (northwestern China) and grouped into 54 flea pools. Flea species were identified according to morphological characteristics and molecular data. In addition, all flea samples were analyzed for Bartonella with amplification and sequencing of a 380-bp part of the gltA gene and Trypanosomatidae with targeting the 18S rRNA (850-bp) and gGAPDH (820-bp) genes. The flea species included Frontopsylla elatoides elatoides (203), Neopsylla mana (49), and Citellophilus tesquorum dzetysuensis (144). Of 54 flea pools, seven (12.96%) tested positive for Bartonella, and three (5.56%) were positive for Trypanosomatidae. Based on BLASTn and phylogenetic analyses, i) Bartonella washoensis in F. elatoides elatoides and C. tesquorum dzetysuensis, and Bartonella rochalimae in F. elatoides elatoides were identified. Interestingly, a new haplotype within the species Ba. washoensis was discovered in C. tesquorum dzetysuensis; and ii) Blechomonas luni was confirmed in C. tesquorum dzetysuensis and Trypanosoma otospermophili in F. elatoides elatoides. Two Bartonella species and two Trypanosomatidae members were discovered for the first time in fleas from LTGRs. This study broadens our understanding of the geographic distribution and potential vectors for Bartonella and Trypanosomatidae.

Oclacitinib (APOQUEL®) is a selective Janus kinase 1 inhibitor with efficacy in a canine model of flea allergic dermatitis.

Oclacitinib is a novel Janus kinase (JAK) inhibitor that potently inhibits JAK1-dependent cytokines involved in allergy, inflammation, and pruritus (IL-2, IL-4, IL-6, IL-13, and IL-31). Oclacitinib (Apoquel®, Zoetis Inc, Parsippany, NJ) is approved for the treatment/control of pruritus associated with allergic dermatitis and treatment/control of clinical manifestations of atopic dermatitis in dogs at least 12 months of age. To evaluate the effectiveness of oclacitinib in dogs with flea allergy dermatitis, the JAK1 selective inhibitor was tested in a placebo-controlled, masked, single-dose (0.4 mg/kg) or repeat-dose (0.4 mg/kg, twice daily for 2 weeks) study. Pruritic behaviors were quantitated by video recording, and erythema and skin lesions were assessed using a 10-cm visual analog scale (VAS). Results showed that oclacitinib reduced pruritus by 61% as early as 1.5 h after a single oral dose compared to placebo, with an average reduction (compared to placebo) of 85% 1-5 h after dosing (0.4 mg/kg; p < .0001). Oclacitinib also significantly reduced erythema (p < .0001) and skin lesion (p < .0005) VAS scores on Day 14 compared to placebo in a repeat dose study. No adverse events were noted during the conduct of these studies. IL-31 concentrations were elevated in the majority of dogs after flea infestation, suggesting JAK1-dependent cytokines may drive clinical signs of flea allergy dermatitis. These findings show that oclacitinib, an inhibitor of JAK1-dependent cytokines involved in allergy and inflammation can rapidly reduce clinical signs associated with flea allergic dermatitis in dogs.

Curiosities take the stage - role-play in parasitology teaching.

Careful observation of parasites, masters of camouflage, reveals an ingenious and fascinating world. However, students often perceive parasitology as impenetrable. What if a flamboyant flea circus director passionately introduced the multidimensional contexts of this discipline? Will role-play capture the imagination of students and guide them in their future learning?

Argopistes Motschulsky from Madagascar with descriptions of six new species (Coleoptera, Chrysomelidae, Galerucinae, Alticini).

The revision of the flea beetle genus Argopistes Motschulsky, 1860 in Madagascar is provided. Six new species are described: Argopistesjanakmoravecorumsp. nov., A.laterosinuatussp. nov., and A.vadoni from the northern area; A.jenisisp. nov., A.keiserisp. nov., and A.seyrigisp. nov. from the central area. A new synonym of Argopistesbrunneus Weise, 1895 is established: A.sexguttatus Weise, 1895, syn. nov., since A.sexguttatus is shown to be a chromatic form of A.brunneus. A diagnostic key of the seven Malagasy Argopistes species is provided, with photographs of the habitus, median lobe of the aedeagus, and spermatheca. Finally, based on known occurrences, the current suitable areas for this flea beetle genus in Madagascar are estimated using Ecological Niche Modelling (ENM) techniques.

Transcriptome analysis of Kunming mice responses to the bite of Xenopsylla cheopis.

BACKGROUND: Flea bites could trigger a series of complex molecular responses in the host. However, our understanding of the responses at the molecular level is still relatively limited. This study quantifies the changes in gene expression in mice after flea bites by RNA sequencing (RNA-seq) from their spleens, revealing the potential biological effects of host response to flea bites. METHODS: RNA-seq was used for transcriptome analysis to screen for differentially expressed genes (DEGs) between the control mice group and the flea bite mice group. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on DEGs. Protein-protein interaction (PPI) network analysis on DEGs related to immune processes was performed. Finally, we randomly selected several genes from the screened DEGs to validate the results from the transcriptome data by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR). RESULTS: A total of 521 DEGs were identified, including 277 upregulated and 244 downregulated. There were 258 GO terms significantly enriched by upregulated DEGs and 419 GO terms significantly enriched by downregulated DEGs. Among the upregulated DEGs, 22 GO terms were associated with immune cells (e.g., B cells and T cells) and immune regulatory processes, while among the downregulated DEGs, 58 GO terms were associated with immune cells and immune regulatory processes. Through PPI analysis, we found that CD40 molecules with significantly downregulated expression levels after flea bites may play an important role in host immune regulation. Through KEGG pathway enrichment analysis, a total of 26 significantly enriched KEGG pathways were identified. The RT-qPCR analysis results indicated that the transcriptome sequencing results were reliable. CONCLUSIONS: Through in-depth analysis of transcriptome changes in mice caused by flea bites, we revealed that flea bites could stimulate a series of biological and immunological responses in mice. These findings not only provided a deeper understanding of the impact of flea bites on the host but also provided a basis for further research on the interaction between ectoparasites and the host. We believe that digging deeper into the significance of these transcriptome changes will help reveal more about the adaptive response of the host to ectoparasites.

Unique microbial communities of parasitic fleas on wild animals from the Qinghai-Tibet Plateau.

Fleas, one of the most significant ectoparasites, play a crucial role as vectors in spreading zoonotic diseases globally. The Qinghai Province, as part of the Qinghai-Tibet Plateau, is one of the provinces in China with the largest number of flea species. In this study, we characterized the microbial communities of eighty-five adult fleas, belonging to nineteen species within four families (Ceratophyllidae, Ctenophthalmidae, Leptopsyllidae, and Pulicidae). We identified a total of 1162 unique operational taxonomic units at the genus level, with flea-borne pathogens such as Wolbachia, Bartonella, Rickettsia being the members of top abundant taxa. Except for comparison between Ctenophthalmidae and Leptopsyllidae families, the analyses of both alpha- and beta- diversity indicators suggested that bacterial diversity varied among flea families. This could be attributed to flea phylogeny, which also influenced by their geographical sites and animal hosts. Results of Linear discriminant analysis effect size (LEfSe) indicated that 29 genera in Ceratophylloidea, 11 genera in Ctenophthalmidae, 15 genera in Leptopsyllidae, and 22 genera in Pulicidae were significantly responsible for explaining the differences among the four flea families (linear discriminant analysis score > 2, P < 0.05). Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) analyses showed that the functional pathways varied significantly across flea families, which was supported by the significant correlation between the functional pathways and the microbial communities.

The complete mitochondrial genome of the rodent flea Nosopsyllus laeviceps: genome description, comparative analysis, and phylogenetic implications.

BACKGROUND: Fleas are one of the most common and pervasive ectoparasites worldwide, comprising at least 2500 valid species. They are vectors of several disease-causing agents, such as Yersinia pestis. Despite their significance, however, the molecular genetics, biology, and phylogenetics of fleas remain poorly understood. METHODS: We sequenced, assembled, and annotated the complete mitochondrial (mt) genome of the rodent flea Nosopsyllus laeviceps using next-generation sequencing technology. Then we combined the new mitogenome generated here with mt genomic data available for 23 other flea species to perform comparative mitogenomics, nucleotide diversity, and evolutionary rate analysis. Subsequently, the phylogenetic relationship within the order Siphonaptera was explored using the Bayesian inference (BI) and maximum likelihood (ML) methods based on concentrated data for 13 mt protein-coding genes. RESULTS: The complete mt genome of the rodent flea N. laeviceps was 16,533 base pairs (bp) in a circular DNA molecule, containing 37 typical genes (13 protein-coding genes, 22 transfer RNA [tRNA] genes, and two ribosomal RNA [rRNA] genes) with one large non-coding region (NCR). Comparative analysis among the order Siphonaptera showed a stable gene order with no gene arrangement, and high AT content (76.71-83.21%) with an apparent negative AT and GC skew except in three fleas Aviostivalius klossi bispiniformis, Leptopsylla segnis, and Neopsylla specialis. Moreover, we found robust evidence that the cytochrome c oxidase subunit 1 (cox1) gene was the most conserved protein-coding gene (Pi = 0.15, non-synonymous/synonymous [Ka/Ks] ratio = 0.13) of fleas. Phylogenomic analysis conducted using two methods revealed different topologies, but both results strongly indicated that (i) the families Ceratophyllidae and Leptopsyllidae were paraphyletic and were the closest to each other, and (ii) the family Ctenophthalmidae was paraphyletic. CONCLUSIONS: In this study, we obtained a high-quality mt genome of the rodent flea N. laeviceps and performed comparative mitogenomics and phylogeny of the order Siphonaptera using the mt database. The results will enrich the mt genome data for fleas, lay a foundation for the phylogenetic analysis of fleas, and promote the evolutionary analysis of Siphonaptera.

Use of a modified SCORFAD scale to define localised reaction patterns associated with a flea burden in cats.

BACKGROUND: The SCORing Feline Allergic Dermatitis scale (SCORFAD) is a validated dermatological scale assessing reaction patterns associated with allergic dermatitis in cats. While no pathognomonic reaction pattern is recognised with flea allergy dermatitis (FAD), miliary dermatitis is more common. HYPOTHESIS/OBJECTIVE: This study aimed to document regional cutaneous reaction patterns of cats with fleas using a modified SCORFAD (mSCORFAD). ANIMALS: In total, 142 owned cats from West Central Florida enrolled over three study periods. To be included, each cat and household environment had five or more fleas on Day (D)0. MATERIALS AND METHODS: Cats were examined on D0, D7, D14, D21, D28, D44, D56 and D80. On D0 they were treated with an isoxazoline and treatment continued through the study. Ten body regions were assessed using mSCORFAD to give a regional score for each of four reaction patterns. These were compared using the Wilcoxon rank sum test. RESULTS: At D80 there was an 80% reduction in total mSCORFAD representing clinical response to ectoparasite control only. The most commonly affected region was the ventral abdomen with a mean mSCORFAD score of 1.8 (95% confidence interval = 1.5-2.1) compared with other body regions (p < 0.01). The most common reaction patterns were self-induced alopecia on the ventral abdomen and miliary dermatitis in the cervical region (p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE: The mSCORFAD suggests that self-induced alopecia on the ventral abdomen and miliary dermatitis in the cervical region is more strongly associated with a flea burden in cats.

Declining aqueous calcium and fish predation risk interactively modify the phenotypic plasticity in Daphnia pulex.

Aqueous calcium (Ca) decline is threatening freshwater ecosystems worldwide. There are great concerns about the possible ecological consequences of Ca limitation combined with biological pressures like predation. Here we investigated the interactions between Ca restriction and fish predation risk on the phenotypic plasticity in the keystone herbivore Daphnia, together with physiological responses underlying the plastic trait changes. Fish predation risk induced D. pulex to mature earlier and produce more but smaller offspring at adequate Ca. Declining Ca inhibited the expression of defensive traits, with the inhibitive degree showing a linear or threshold-limited dynamic. The presence of predation risk mitigated the negative effect of declining Ca on reducing body size but exacerbated the delay in maturity, indicating a life history trade-off for larger body size rather than the current reproduction in multi-stressed Daphnia. Actin 3-mediated cytoskeleton and AMPK ß-mediated energy metabolism were highly correlated with these plastic trait changes. Altered phenotypic plasticity in planktonic animals is expected to trigger many ecological impacts from individual fitness to community structure, thus providing new insights into the mechanisms underlying decreased Ca affecting lake ecosystems.

A case of mistaken identity: a systematic review, meta-analysis, and reinvestigation of hemotropic Mycoplasma spp. infection in Ctenocephalides felis (cat flea).

BACKGROUND: Feline-associated hemotropic Mycoplasma (hemoplasmas) are believed to be transmitted by two primary mechanisms: (1) direct transmission via fighting and (2) vector-borne transmission by the cat flea (Ctenocephalides felis). While the efficiency of transmission by C. felis appears low, most manuscripts focus on the prevalence of hemoplasmas in wild-caught fleas and report either a very low (< 3%) or a high (> 26%) prevalence. Therefore, we aimed to assess the influence of sample processing and PCR methods on C. felis hemoplasma infection prevalence. METHODS: A systemic review of PubMed articles identified 13 manuscripts (1,531 fleas/flea pools) that met the inclusion criteria (performed PCR for >1 hemoplasma on C. felis collected from cats). Risk of bias was assessed utilizing the ROBINS-E tool. Meta-analysis performed in R of these manuscripts found that not washing samples and a common set of 16S rRNA primers first published in Jensen et al. 2001 were associated with increased hemoplasma prevalence. To evaluate the influence of washing on newly collected fleas, we assessed the hemoplasma status of 20 pools of 5 C. felis each, half of which were washed and half not washed. RESULTS: Flea washing did not influence the detection of hemoplasma but instead amplified Spiroplasma. To assess non-specific amplification with the Jensen et al. 2001 primers, 67 C. felis samples (34% previously reported hemoplasma infected) were subject to PCR and sequencing. By this method, hemoplasma was detected in only 3% of samples. In the remaining "hemoplasma infected" fleas, PCR amplified Spiroplasma or other bacteria. CONCLUSIONS: Therefore, we concluded that hemoplasma infection in C. felis is rare, and future flea prevalence studies should sequence all positive amplicons to validate PCR specificity. Further investigation of alternative methods of feline-associated hemoplasma transmission and the ability of C. felis to maintain hemoplasma infection is necessary.

Severe flea-borne typhus complicated by hemophagocytic lymphohistiocytosis: A case report and review of literature.

Flea-borne typhus (FBT), also known as murine typhus, is a zoonotic infection caused by R. typhi with world-wide distribution. In the United States, the infection is uncommon but remains endemic in some areas, including Los Angeles County. It typically manifests as a benign acute febrile illness but can be complicated in a minority of cases. Associated hemophagocytic lymphohistiocytosis (HLH) has been described in a limited number of cases. Here, we present a case of a patient with FBT complicated by HLH treated empirically with doxycycline with subsequent resolution of HLH. Also included is a review of the literature of other published cases.

Salivary glands of the cat flea, Ctenocephalides felis: Dissection and microscopy guide.

Fleas are morphologically unique ectoparasites that are hardly mistaken for any other insect. Most flea species that feed on humans and their companion animals, including the cat flea (Ctenocephalides felis), have medical and veterinary importance. Besides facilitating blood acquisition, salivary biomolecules can modulate pathogen transmission. Thus, dissection of salivary glands is essential for comprehensive studies on disease vectors like the cat flea. Herein, we present the pictorial dissection protocol assisting future research targeting individual flea organs, for revealing their roles in vector competence and physiology. We provide a comprehensive guide, allowing researchers, even with limited practical experience, to successfully perform microdissection for collecting cat flea salivary glands. Furthermore, the protocol does not require expensive, sophisticated equipment and can be accomplished with routinely available tools. We illustrated expected results with morphological changes of salivary glands upon blood feeding as well as fluorescently stained these organs.