Macròlids: mecanismes d'acció i de resistència

Els macròlids són agents descrits per primera vegada als anys cinquanta, molt emprats en el tractament de microorganismes grampositius. Actuen al ribosoma, unint-se de manera reversible a la subunitat 50S. Actualment se'n coneixen diferents mecanismes de resistència, que van des de la modificació de la diana fins a la desactivació de l'antibiòtic, passant per bombes d'expulsió o problemes de permeabilitat.Macrolides are agents described by first time in the 50s. These agents are extensively used in the infections by gram-positive microorganisms. They act in the ribosome, by means of a reversible union with the 50S subunit. Currently we know different resistance mechanisms, and those include target modification, antibiotic inactivation, efflux pumps or impermeability

The Role of Chiggers as Human Pathogens

Trombiculid mites (Acari: Trombiculidae) are distributed worldwide ectoparasites of a wide range of vertebrates. More than 50 species are known to bite humans, and about 20 have medical importance. The larval stages (chiggers) of the genus Leptotrombidium are vectors of Orientia tsutsugamushi, causative agent of scrub typhus. This life-threatening disease is widely endemic in Asian Pacific regions where more than one billion people are at risk of acquiring the infection and around one million new cases are estimated to occur annually. In addition, although underreported and often misdiagnosed, trombiculiasis, defined as a dermatitis caused by the salivary secretion of biting chiggers, is present in America and Europe

Human Rickettsia sibirica mongolitimonae Infection, Spain

Human Rickettsia sibirica mongolitimonae Infection, Spai

Role of Birds in Dispersal of Etiologic Agents of Tick-borne Zoonoses, Spain, 2009

We amplified gene sequences from Anaplasma phagocytophilum, Borrelia garinii, B. valaisiana, B. turdi, Rickettsia monacensis, R. helvetica, R. sibirica sibirica, and Rickettsia spp. (including Candidatus Rickettsia vini) in ticks removed from birds in Spain. The findings support the role of passerine birds as possible dispersers of these tick-borne pathogens

Bartonella spp. Prevalence (Serology, Culture, and PCR) in Sanitary Workers in La Rioja Spain

Bartonella spp. are increasingly implicated in association with a spectrum of zoonotic infectious diseases. One hundred sanitary workers in La Rioja, Spain, completed a questionnaire and provided blood specimens for Bartonella spp. serology and Bartonella Alpha-Proteobacteria growth medium (BAPGM) enrichment blood culture/PCR. Six immunofluorescence assays (IFA) were performed and aseptically obtained blood specimens were inoculated into liquid BAPGM and subcultured onto blood agar plates. Bartonella DNA was amplified using conventional and real-time PCR assays. The Bartonella spp., strain, or genotype was determined by DNA sequencing. Bartonella seroreactivity was documented in 83.1% and bloodstream infection in 21.6% of participants. Bartonella henselae, B. vinsonii subsp. berkhoffii genotypes I and III, and B. quintana were identified. IFA seroreactivity and PCR positivity were not statistically associated with self-reported symptoms. Our results suggest that exposure to and non-clinical infection with Bartonella spp. may occur more often than previously suspected in the La Rioja region.This research was funded by Bayer Animal Health GmbH (Leverkusen, Germany), grant number 2111116219

La pulga humana Pulex irritans (Siphonaptera: Pulicidae) en el noroeste argentino, una investigación de Bartonella y Rickettsia spp.

Pulex irritans es la única especie cosmopolita y la más estudiada dentro del género Pulex. Tiene importancia en la salud pública ya que comúnmente parasita a los seres humanos causando dermatitis y también ha sido implicada en la transmisión de patógenos bacterianos. Pulex irritans se ha confundido con la especie cercana Pulex simulans durante años. En este sentido, se identificaron los especímenes de Pulex recolectados de un zorro pampeano y un pecarí del Chaco del noroeste de la Argentina por comparación con los ejemplares tipo. Además, se investigó la presencia de Bartonella spp. y Rickettsia spp. utilizando ensayos de PCR. Nuestros resultados aportaron caracteres de importancia diagnóstica para identificar a P. irritans, que incluyen la forma del esternito VII en las hembras y del esclerito aedeagal, clasper y crochet en los machos. Además, se reporta por primera vez a P. irritans parasitando un pecarí. Este hallazgo refuerza la hipótesis del origen de esta pulga asociada con este mamífero y luego coloniza humanos y mamíferos domésticos. No hubo evidencia de ADN de Bartonella ni de Rickettsia en las pulgas analizadas. Esta información, si bien negativa, puede ser considerada relevante para P. irritans de Argentina.Pulex irritans is the only cosmopolitan flea species and the most studied one within the genus Pulex. It has importance in public health since it commonly parasitizes humans causing dermatitis, and it has been also implicated in the transmission of bacterial pathogens. Pulex irritans has been confused with the closely related Pulex simulans species for years. Herein, Pulex specimens collected from a Pampas fox and a Chacoan peccary from northwestern Argentina were identified by comparison with type specimens. In addition, the presence of Bartonella spp. and Rickettsia spp. was investigated using PCR assays. Our results provided characters of diagnostic importance to identify P. irritans, which include the shape of sternite VII in the females, and of the aedeagal sclerite, clasper and crochet in the males. Besides, we report for the first time P. irritans parasitizing a peccary. This finding reinforces the hypothesis of the origin of this flea associated with this mammal, and then colonizing humans and domestic mammals. There was no evidence of Bartonella or Rickettsia DNA in the analyzed fleas. This information even if negative may be considered relevant for P. irritans from Argentina.Fil: Lareschi, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Venzal, José M.. Universidad de la República; UruguayFil: Nava, Santiago. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mangold, Atilio Jose. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Portillo, Aránzazu. Universidad de la República; UruguayFil: Palomar Urbina, Ana María. Centro de Investigación Biomédica de La Rioja; EspañaFil: Oteo Revuelta, José Antonio. Centro de Investigación Biomédica de La Rioja; Españ

La pulga humana Pulex irritans (Siphonaptera: Pulicidae) en el noroeste argentino, una investigación de Bartonella y Rickettsia spp.

Pulex irritans is the only cosmopolitan flea species and the most studied one within the genus Pulex. It has importance in public health since it commonly parasitizes humans causing dermatitis, and it has been also implicated in the transmission of bacterial pathogens. Pulex irritans has been confused with the closely related Pulex simulans species for years. Herein, Pulex specimens collected from a Pampas fox and a Chacoan peccary from northwestern Argentina were identified by comparison with type specimens. In addition, the presence of Bartonella spp. and Rickettsia spp. was investigated using PCR assays. Our results provided characters of diagnostic importance to identify P. irritans, which include the shape of sternite VII in the females, and of the aedeagal sclerite, clasper and crochet in the males. Besides, we report for the first time P. irritans parasitizing a peccary. This finding reinforces the hypothesis of the origin of this flea associated with this mammal, and then colonizing humans and domestic mammals. There was no evidence of Bartonella or Rickettsia DNA in the analyzed fleas. This information even if negative may be considered relevant for P. irritans from Argentina.Pulex irritans es la única especie cosmopolita y la más estudiada dentro del género Pulex. Tiene importancia en la salud pública ya que comúnmente parasita a los seres humanos causando dermatitis y también ha sido implicada en la transmisión de patógenos bacterianos. Pulex irritans se ha confundido con la especie cercana Pulex simulans durante años. En este sentido, se identificaron los especímenes de Pulex recolectados de un zorro pampeano y un pecarí del Chaco del noroeste de la Argentina por comparación con los ejemplares tipo. Además, se investigó la presencia de Bartonella spp. y Rickettsia spp. utilizando ensayos de PCR. Nuestros resultados aportaron caracteres de importancia diagnóstica para identificar a P. irritans, que incluyen la forma del esternito VII en las hembras y del esclerito aedeagal, clasper y crochet en los machos. Además, se reporta por primera vez a P. irritans parasitando un pecarí. Este hallazgo refuerza la hipótesis del origen de esta pulga asociada con este mamífero y luego coloniza humanos y mamíferos domésticos. No hubo evidencia de ADN de Bartonella ni de Rickettsia en las pulgas analizadas. Esta información, si bien negativa, puede ser considerada relevante para P. irritans de Argentina.Centro de Estudios Parasitológicos y de Vectore

Old zoonotic agents and novel variants of tick-borne microorganisms from Benguela (Angola), July 2017

Anaplasmataceae; Ticks; Zoonotic agentsAnaplasmatàcies; Paparres; Agents zoonòticsAnaplasmatáceas; Garrapatas; Agentes zoonóticosBackground Ticks and tick-borne diseases constitute a real threat for the livestock industry, which is increasing in Angola. In addition, ticks are vectors of zoonoses of public health concern, and scarce information is available from this country. In an effort to contribute to the prevention of zoonotic infectious diseases affecting humans and animals, the molecular screening of certain tick-related microorganisms collected on cattle in Angola was performed under a ‘One Health’ scope. Methods Ticks collected from cattle in Cubal (Benguela Province, Angola) in July 2017 were analysed in pools using specific PCR assays for bacteria (Rickettsia, Anaplasmataceae, Borrelia, Coxiella and Spiroplasma) and protozoa (Theileria and Babesia) detection. Results A total of 124 tick specimens were grouped in 25 pools (two Amblyomma variegatum, three Hyalomma truncatum, 16 Rhipicephalus decoloratus, two Rhipicephalus duttoni, one Rhipicephalus evertsi mimeticus and one Rhipicephalus sp.). The amplified microorganisms were (pools): Rickettsia africae (two A. variegatum and one R. decoloratus), Rickettsia aeschlimannii (three H. truncatum), Ehrlichia spp. (six R. decoloratus), Coxiella spp. (all but H. truncatum), Francisella sp. (one H. truncatum), Spiroplasma sp. closely related to Spiroplasma ixodetis (three R. decoloratus), Babesia bigemina (two R. decoloratus) and Babesia spp. (two A. variegatum). The obtained nucleotide sequences from Ehrlichia spp., two Coxiella genotypes (from R. duttoni and Rhipicephalus sp.), Francisella sp. and Babesia spp. (from A. variegatum) reached low identities with known genetically characterized species. Conclusions This study demonstrates the circulation in Angola of the pathogen R. aeschlimannii and potential novel tick-related microorganisms belonging to Ehrlichia, Coxiella, Francisella, Spiroplasma and Babesia spp. and corroborates the presence of R. africae and B. bigemina. Our results should be considered in developing protocols for the management of fever of unknown origin and for veterinary practices. Further studies are required to evaluate the risk of tick-borne diseases in Angola.This work has been partially funded by European Regional Development Funds (FEDER)

Bartonella spp. Prevalence (Serology, Culture, and PCR) in Sanitary Workers in La Rioja Spain

This research was funded by Bayer Animal Health GmbH (Leverkusen, Germany), grant number 2111116219.Bartonella spp. are increasingly implicated in association with a spectrum of zoonotic infectious diseases. One hundred sanitary workers in La Rioja, Spain, completed a questionnaire and provided blood specimens for Bartonella spp. serology and Bartonella Alpha-Proteobacteria growth medium (BAPGM) enrichment blood culture/PCR. Six immunofluorescence assays (IFA) were performed and aseptically obtained blood specimens were inoculated into liquid BAPGM and subcultured onto blood agar plates. Bartonella DNA was amplified using conventional and real-time PCR assays. The Bartonella spp., strain, or genotype was determined by DNA sequencing. Bartonella seroreactivity was documented in 83.1% and bloodstream infection in 21.6% of participants. Bartonella henselae, B. vinsonii subsp. berkhoffii genotypes I and III, and B. quintana were identified. IFA seroreactivity and PCR positivity were not statistically associated with self-reported symptoms. Our results suggest that exposure to and non-clinical infection with Bartonella spp. may occur more often than previously suspected in the La Rioja region