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PloS One 2023The hematophagous behaviour emerged independently in several instances during arthropod evolution. Survey of salivary gland and saliva composition and its...
The hematophagous behaviour emerged independently in several instances during arthropod evolution. Survey of salivary gland and saliva composition and its pharmacological activity led to the conclusion that blood-feeding arthropods evolved a distinct salivary mixture that can interfere with host defensive response, thus facilitating blood acquisition and pathogen transmission. The cat flea, Ctenocephalides felis, is the major vector of several pathogens, including Rickettsia typhi, Rickettsia felis and Bartonella spp. and therefore, represents an important insect species from the medical and veterinary perspectives. Previously, a Sanger-based sialome of adult C. felis female salivary glands was published and reported 1,840 expressing sequence tags (ESTs) which were assembled into 896 contigs. Here, we provide a deeper insight into C. felis salivary gland composition using an Illumina-based sequencing approach. In the current dataset, we report 8,892 coding sequences (CDS) classified into 27 functional classes, which were assembled from 42,754,615 reads. Moreover, we paired our RNAseq data with a mass spectrometry analysis using the translated transcripts as a reference, confirming the presence of several putative secreted protein families in the cat flea salivary gland homogenates. Both transcriptomic and proteomic approaches confirmed that FS-H-like proteins and acid phosphatases lacking their putative catalytic residues are the two most abundant salivary proteins families of C. felis and are potentially related to blood acquisition. We also report several novel sequences similar to apyrases, odorant binding proteins, antigen 5, cholinesterases, proteases, and proteases inhibitors, in addition to putative novel sequences that presented low or no sequence identity to previously deposited sequences. Together, the data represents an extended reference for the identification and characterization of the pharmacological activity present in C. felis salivary glands.
Topics: Animals; Female; Ctenocephalides; Proteomics; Salivary Glands; Saliva; Rickettsia felis; Flea Infestations
PubMed: 36649293
DOI: 10.1371/journal.pone.0279070 -
Ticks and Tick-borne Diseases Mar 2023Rickettsioses are vector-borne zoonotic diseases whose etiological agents are bacteria of the genera Rickettsia and Orientia. In Colombia, literature published on...
Rickettsioses are vector-borne zoonotic diseases whose etiological agents are bacteria of the genera Rickettsia and Orientia. In Colombia, literature published on rickettsioses during the 20th century is limited and disperse; to date, there are no detailed publications that compile the affected regions or the involved Rickettsia species in each outbreak. Since early works of Luis Patiño-Camargo, the study of rickettsioses gained major importance with the subsequent description of significant outbreaks in some departments of the country. During the 1940s, many articles were published reporting outbreaks probably caused by Rickettsia rickettsii, Rickettsia typhi, and Rickettsia prowazekii, as well as studies on their diagnosis, vaccination, and prophylaxis. One of the most notorious works was published by Patiño-Camargo where he named the R. rickettsii rickettsiosis as "Tobia fever". However, in the subsequent decades, these entities entered a prolonged period of neglected research and surveillance, and just gained importance until the 21st century, when new fatal cases began to be reported in the country; thus, many questions remained unanswered during this overlooked period. The present work reviewed online databases, repositories, and libraries to compile literature related to rickettsioses in Colombia published during the 20th century. Gathered data show that typhus group rickettsioses (including infections by R. typhi and R. prowazekii) were broadly distributed in departments from the Andean and Caribbean regions, and that spotted fever group rickettsioses cases (including infections by R. rickettsii) were registered in other locations different from Tobia (Cundinamarca), like Atlántico, Bolivar, and Santander departments. These findings contribute to the knowledge of these diseases, their historical distribution, public health burden, and set new horizons for rickettsioses research in different Colombian locations.
Topics: Male; Humans; Colombia; Rickettsia Infections; Rickettsia; Rickettsia prowazekii; Rickettsia rickettsii
PubMed: 36628901
DOI: 10.1016/j.ttbdis.2022.102118 -
Emerging Infectious Diseases Jan 2023Whether increases in typhus group rickettsiosis in Galveston County, Texas, USA, are caused by increased recognition or true reemergence is unclear. We conducted a...
Whether increases in typhus group rickettsiosis in Galveston County, Texas, USA, are caused by increased recognition or true reemergence is unclear. We conducted a serosurvey that demonstrated Rickettsia typhi antibodies increased from 1.2% in 2013 to 7.8% in 2021 (p<0.001). These findings support pathogen reemergence rather than enhanced recognition alone.
Topics: Humans; Typhus, Endemic Flea-Borne; Rickettsia typhi; Typhus, Epidemic Louse-Borne; Texas; Seroepidemiologic Studies
PubMed: 36573645
DOI: 10.3201/eid2901.221206 -
PloS One 2022Over the past 10 years, studies using high-throughput 16S rRNA gene sequencing have shown that mosquitoes harbor diverse bacterial communities in their digestive system....
Over the past 10 years, studies using high-throughput 16S rRNA gene sequencing have shown that mosquitoes harbor diverse bacterial communities in their digestive system. However, no previous research has examined the total bacteria community inside versus outside of mosquitoes and whether bacteria found on the outside could represent a potential health threat through mechanical transfer. We examined the bacterial community of the external surface and internal body of female Anopheles coluzzii adults collected from homes in Côte d'Ivoire, Africa, by Illumina sequencing of the V3 to V4 region of 16S rRNA gene. Anopheles coluzzii is in the Anopheles gambiae sensu lato (s.l.) species complex and important in the transmission of malaria. The total 16S rRNA reads were assigned to 34 phyla, 73 orders, 325 families, and 700 genera. At the genus level, the most abundant genera inside and outside combined were Bacillus, Staphylococcus, Enterobacter, Corynebacterium, Kocuria, Providencia, and Sphingomonas. Mosquitoes had a greater diversity of bacterial taxa internally compared to the outside. The internal bacterial communities were similar between homes, while the external body samples were significantly different between homes. The bacteria on the external body were associated with plants, human and animal skin, and human and animal infections. Internally, Rickettsia bellii and Rickettsia typhi were found, potentially of importance, since this genus is associated with human diseases. Based on these findings, further research is warranted to assess the potential mechanical transmission of bacteria by mosquitoes moving into homes and the importance of the internal mosquito microbiota in human health.
Topics: Animals; Humans; Anopheles; RNA, Ribosomal, 16S; Cote d'Ivoire; Malaria; Bacteria; Microbiota; Mosquito Vectors
PubMed: 36520830
DOI: 10.1371/journal.pone.0278912 -
Frontiers in Cellular and Infection... 2022Rickettsia is a genus of nonmotile, Gram-negative, non-spore-forming, highly pleomorphic bacteria that cause severe epidemic rickettsioses. The spotted fever group and... (Review)
Review
Rickettsia is a genus of nonmotile, Gram-negative, non-spore-forming, highly pleomorphic bacteria that cause severe epidemic rickettsioses. The spotted fever group and typhi group are major members of the genus Rickettsia. Rickettsial species from the two groups subvert diverse host cellular processes, including membrane dynamics, actin cytoskeleton dynamics, phosphoinositide metabolism, intracellular trafficking, and immune defense, to promote their host colonization and intercellular transmission through secreted effectors (virulence factors). However, lineage-specific rickettsiae have exploited divergent strategies to accomplish such challenging tasks and these elaborated strategies focus on distinct host cell processes. In the present review, we summarized current understandings of how different rickettsial species employ their effectors' arsenal to affect host cellular processes in order to promote their own replication or to avoid destruction.
Topics: Humans; Rickettsia; Rickettsia Infections; Signal Transduction
PubMed: 36389139
DOI: 10.3389/fcimb.2022.995933 -
Pathogens (Basel, Switzerland) Sep 2022Acute febrile illness (AFI) is a morbid condition with a sudden onset of fever with at least seven days of evolution, where no signs or symptoms related to an apparent...
Acute febrile illness (AFI) is a morbid condition with a sudden onset of fever with at least seven days of evolution, where no signs or symptoms related to an apparent infection have been identified. In Latin America, a high proportion of disease is typically due to malaria and arboviruses. However, among the infectious etiologies, tick-borne diseases (TBDs) should also be considered, especially in areas where people come into direct contact with these arthropods. This study aims to describe the etiology and epidemiology related to tick-borne agents in patients with AFI and the tick's natural infection by agents of TBD in the rural tropical Magdalena Medio region in Colombia, and explore the factors associated with the presence of infection. We conduct a cohort study enrolling 271 patients with AFI to detect the bacteria of the genera , and through molecular techniques, and additionally evaluate the presence of IgG antibodies with commercially available kits. We also conduct tick collection in the patient's households or workplaces for the molecular screening of the same bacterial genera. Seropositivity to IgG antibodies was obtained for all the bacteria analyzed, with being the most common at 39.5% (107/271), followed by at 31.4% (85/271), at 26.9% (73/271), at 15.5% (42/271), at 14.4% (39/271), and at 6.6% (18/271). However, these bacteria were not detected by the molecular techniques used. infection was detected in 39.5% of the patients: 49.5% only by phase I and II IgG antibodies, 33.6% only by real-time PCR, and 16.8% had a concordant positive result for both techniques. A total of 191 adult ticks, 111 females and 80 males, were collected and identified as s.l. and . In the 169 adult ticks in which natural infection was evaluated, spp. was detected in 21.3% (36/169), spp. in 11.8% (20/169), and spp. in 4.7% (8/169). In conclusion, we identified the prior exposition to , and in patients through serological tests. We also detected the infection of using molecular techniques. In the ticks, we identified bacteria of the genera and . These results suggest the importance of these zoonotic agents as possible causes of AFI in this region.
PubMed: 36297148
DOI: 10.3390/pathogens11101090 -
PloS One 2022Understanding the distribution of pathogens causing acute febrile illness (AFI) is important for clinical management of patients in resource-poor settings. We evaluated...
Understanding the distribution of pathogens causing acute febrile illness (AFI) is important for clinical management of patients in resource-poor settings. We evaluated the proportion of AFI caused by specific pathogens among outpatients in Bangladesh. During May 2019-March 2020, physicians screened patients aged ≥2 years in outpatient departments of four tertiary level public hospitals. We randomly enrolled patients having measured fever (≥100.4°F) during assessment with onset within the past 14 days. Blood and urine samples were tested at icddr,b through rapid diagnostic tests, bacterial culture, and polymerase chain reaction (PCR). Acute and convalescent samples were sent to the Centers for Disease Control and Prevention (USA) for Rickettsia and Orientia (R/O) and Leptospira tests. Among 690 patients, 69 (10%) had enteric fever (Salmonella enterica serotype Typhi orSalmonella enterica serotype Paratyphi), 51 (7.4%) Escherichia coli, and 28 (4.1%) dengue detected. Of the 441 patients tested for R/O, 39 (8.8%) had rickettsioses. We found 7 (2%) Leptospira cases among the 403 AFI patients tested. Nine patients (1%) were hospitalized, and none died. The highest proportion of enteric fever (15%, 36/231) and rickettsioses (14%, 25/182) was in Rajshahi. Dhaka had the most dengue cases (68%, 19/28). R/O affected older children and young adults (IQR 8-23 years) and was detected more frequently in the 21-25 years age-group (17%, 12/70). R/O was more likely to be found in patients in Rajshahi region than in Sylhet (aOR 2.49, 95% CI 0.85-7.32) between July and December (aOR 2.01, 1.01-5.23), and who had a history of recent animal entry inside their house than not (aOR 2.0, 0.93-4.3). Gram-negative Enterobacteriaceae were the most common bacterial infections, and dengue was the most common viral infection among AFI patients in Bangladeshi hospitals, though there was geographic variability. These results can help guide empiric outpatient AFI management.
Topics: Bangladesh; COVID-19; Delivery of Health Care; Dengue; Fever; Hospitals; Humans; Leptospira; Outpatients; Pandemics; Rickettsia; Rickettsia Infections; Salmonella paratyphi A; Typhoid Fever
PubMed: 36048788
DOI: 10.1371/journal.pone.0273902 -
Proceedings (Baylor University. Medical... 2022Murine typhus is a rare condition caused by the gram-negative bacterium which classically presents with the triad of fever, rash, and headache. Herein we report a rare...
Murine typhus is a rare condition caused by the gram-negative bacterium which classically presents with the triad of fever, rash, and headache. Herein we report a rare presentation of murine typhus in an adult who presented predominantly with fever and gastrointestinal symptoms. Initial imaging showed cardiomegaly and hepatosplenomegaly, which led to further workup revealing rickettsial disease. Although this illness is considered a rare diagnosis in the emergency department, every person with a pet that might have fleas is susceptible to it.
PubMed: 35991722
DOI: 10.1080/08998280.2022.2078640 -
Journal of Global Infectious Diseases 2022Co-infection with different agents such as bacterial, viral, and Rickettsia is being increasingly recognized due to greater availability and utilization of the...
INTRODUCTION
Co-infection with different agents such as bacterial, viral, and Rickettsia is being increasingly recognized due to greater availability and utilization of the diagnostic tests among malaria patients.
METHODS
Consecutive admitted malarial cases were included and were subjected to test for general investigations, bacteria, typhoid, dengue, chikungunya, and rest for specific diagnosis. All patients were followed up till discharge or death and appropriate statistical tests were performed.
RESULTS
A total of 152 malaria patients were recruited and 27 (18.8%) had concurrent infections. It included 40.7% dengue only, 18.7% pneumonia, 11.1% urinary tract infection (UTI), 7.4% enteric fever, 3.7% leptospirosis, chikungunya, and tuberculous meningitis each, and 3.7% each of dengue with pneumonia and UTI. The organisms isolated were and The mean duration of fever was 6.33 ± 3.63 days with a range of 3-20 days. Blood culture grew in 2 cases and Dengue co-infections had significantly higher clinical and laboratory features of dengue and complications such as bleeding, jaundice, and cholecystitis, whereas rest concurrent infections had a significantly higher proportion of nausea and vomiting, convulsion, altered sensorium, productive cough, urinary symptoms, shock, acute kidney injury, anemia, and mean neutrophil count. There was significantly higher mortality among malaria-dengue concurrent infection group with 2 (15.4%) than malaria mono-infection group 3 (2.4%).
CONCLUSION
Co-infections with malaria are not uncommon, especially dengue fever and other bacterial infections. The dominant clinical picture is of the superimposed infection. Decision should be clinically guided adjunct with specific diagnostic tests, and timely treatment has favorable outcome.
PubMed: 35910822
DOI: 10.4103/jgid.jgid_279_21 -
The American Journal of Tropical... Jul 2022Murine typhus is an acute undifferentiated febrile illness caused by Rickettsia typhi. In the United States, its reemergence appears to be driven by a shift from the...
Murine typhus is an acute undifferentiated febrile illness caused by Rickettsia typhi. In the United States, its reemergence appears to be driven by a shift from the classic rat-rat flea cycle of transmission to one involving opossums (Didelphis virginiana) and cat fleas. Little is known of the ability of opossums to act as a reservoir and amplifying host for R. typhi. Here, we use Monodelphis domestica (the laboratory opossum) as a surrogate for D. virginiana. Opossums were inoculated via the intraperitoneal (IP) or intradermal (ID) route with 1 × 106 viable R. typhi. Blood and tissues were collected on days 6, 13, 20, and 27 or if moribund. Although one ID-infected opossum died, the remainder did not appear ill, whereas half of the IP-inoculated animals succumbed to infection. Rickettsemia was demonstrated in all animals through week 2 of infection and sporadically in weeks 3 and 4. Rickettsia typhi DNA was detected in all tissues, with most animals demonstrating the presence of bacteria into weeks 3 and 4. Histopathology and immunohistochemistry demonstrated typical findings of rickettsial infection. Akin to infection in rats, the demonstration of disseminated infection, typical inflammation, and prolonged rickettsemia with relatively few clinical effects (especially in the more natural route of ID inoculation) supports the potential of opossums to act as a competent mammalian reservoir and component of the zoonotic maintenance cycle of R. typhi. Understanding the dynamics of infection within opossums may have implications for the prevention and control of murine typhus.
Topics: Animals; Didelphis; Mice; Monodelphis; Rats; Rickettsia; Rickettsia Infections; Rickettsia typhi; Siphonaptera; Typhus, Endemic Flea-Borne
PubMed: 35895366
DOI: 10.4269/ajtmh.21-1076