Citomegalovirus: modalidades broncopulmonares de presentación

Citomegalovirus (CMV) es un herpesviridae, endémico de amplia distribución mundial, debido a su alta tasa de transmisión, especialmente en países de bajo nivel socioeconómico. CMV es un importante agente patógeno en el período embrionario-fetal, siendo el principal agente etiológico del síndrome de TORCH. Por su capacidad de infectar diferentes órganos puede producir una variedad de cuadros clínicos, las formas más graves y frecuentes afectan al aparato respiratorio, gastrointestinal, sistema nervioso central y la retina. En el aparato respiratorio CMV se manifiesta de diversas maneras, dependiendo de la edad y del estado inmunológico del huésped. En inmuno- deprimidos produce neumonías intersticiales graves; sin embargo, ocasionalmente afecta a individuos inmuno- competentes manifestándose como neumonía del primer trimestre, síndrome coqueluchoídeo o enfermedad pulmonar intersticial crónica. En la actualidad el método diagnóstico de elección es el cultivo acelerado de shell vial de muestra obtenida mediante lavado broncoalveolar, presenta alta sensibilidad y especificidad. El tratamiento con ganciclovir ha mejorado el pronóstico. El objetivo de este artículo es mostrar las diferentes formas de presentación clínica del CMV en el aparato respiratorio en pediatría y la respuesta al tratamiento utilizado.

Emerging Aspects of Coxiella burnetii and Molecular Identification along with Treatment Approaches

Q fever is an infectious disease caused by Coxiella burnetii which is an obligatory intracellular parasite. Globally Q fever is a widespread zoonosis. It is characterized by headaches, sudden fever and atypical pneumonia. In the rural environment, the main reservoir includes goats, sheep, cows, dogs, cats and rabbits. The main reservoir of this bacteria is considered domestic animals. They produce in a large number in amniotic fluid and placenta during childbirth. The main route of infection is inhalation. Q fever can cause both acute and chronic infection, mostly asymptomatic in humans and animals. Inactivated whole-cell bacteria vaccination strategy has been performed which provides effective outcomes in humans and animals but many side effects have been observed. The recombinant vaccine has been developed and provides many effective results in experimental conditions. One of the major challenges is the lack of accurate diagnosis facilities if it becomes possible, the prognosis of disease development can be reduced. Direct detection of bacteria is the accurate test for the diagnosis. Different procedures are involved in this method such as immunodetection, PCR amplification and shell vial cell culture. Due to the severe infectivity of C. burnetii all these procedures require a biosafety level 3 lab and qualified staff. Q fever is a challenging disease for scientists to reduce its burden globally. The review discloses the Coxiella burnetii genome, the clinical manifestation of Q fever as well as emerging issues, diagnosis, treatment, prevention and future directions.

High-Content Screening, a Reliable System for Coxiella burnetii Isolation from Clinical Samples

ABSTRACT Q fever, caused by Coxiella burnetii, is a worldwide zoonotic disease that may cause severe forms in humans and requires a specific and prolonged antibiotic treatment. Although current serological and molecular detection tools allow a reliable diagnosis of the disease, culture of C. burnetii strains is mandatory to assess their susceptibility to antibiotics and sequence their genome in order to optimize patient management and epidemiological studies. However, cultivating this fastidious microorganism is difficult and restricted to reference centers, as it requires biosafety level 3 laboratories and relies on cell culture performed by experienced technicians. In addition, the culture yield is low, which results in a small number of isolates being available. In this work, we developed a novel high-content screening (HCS) isolation strategy based on optimized high-throughput cell culture and automated microscopic detection of infected cells with specifically designed algorithms targeting cytopathic effects. This method was more efficient than the shell vial assay, at the level of time dependency, when applied to both frozen specimens (7 isolates recovered by HCS only, sensitivity 91% versus 78% for shell vial) and fresh samples (1 additional isolate using HCS, sensitivity 7% versus 5% for shell vial), for which most strains were recovered more rapidly with the new technique. In addition, detecting positive cultures by an automated microscope reduced the need for expertise and saved 24% of technician working time. Application of HCS to antibiotic susceptibility testing of 12 strains demonstrated that it was as efficient as the standard procedure that combines shell vial culture and quantitative PCR.

High Content Screening, a reliable system for Coxiella burnetii isolation from clinical samples

Q fever, caused by Coxiella burnetii, is a worldwide zoonotic disease that may cause severe forms in humans and requires a specific and prolonged antibiotic treatment. Although the current serological and molecular detection tools enable a reliable diagnosis of the disease, culture of C. burnetii strains is mandatory to evaluate their antibiotic susceptibility and sequence their genome in order to optimize patient management and epidemiological studies. However, cultivating this fastidious microorganism is difficult and restricted to reference centers as it requires biosafety-level 3 laboratories and relies on cell culture performed by experienced technicians. In addition, the culture yield is low, which results in a small number of isolates being available. In this work, we developed a novel high content screening (HCS) isolation strategy based on optimized high-throughput cell culture and automated microscopic detection of infected cells with specifically-designed algorithms targeting cytopathic effects. This method was more efficient than the shell-vial assay when applied to both frozen specimens (7 isolates recovered by HCS only, sensitivity 91% vs 78% for shell-vial) and fresh samples (1 additional isolate using HCS, sensitivity 7% vs 5% for shell-vial). In addition, detecting positive cultures by an automated microscope reduced the need for expertise and saved 24% of technician working time. Application of HCS to antibiotic susceptibility testing of 12 strains demonstrated that it was as efficient as the standard procedure that combines shell-vial culture and quantitative PCR. Overall, this high-throughput HCS system paves the way to the development of improved cell culture isolation of human viruses.

Transfection of Culicoides sonorensis biting midge cell lines with Wolbachia pipientis

Background Biting midges of the genus Culicoides vector multiple veterinary pathogens and are difficult to control. Endosymbionts particularly Wolbachia pipientis may offer an alternative to control populations of Culicoides and/or impact disease transmission in the form of population suppression or replacement strategies. Methods Culicoides sonorensis cell lines were transfected with a Wolbachia infection using a modified shell vial technique. Infections were confirmed using PCR and cell localization using fluorescent in situ hybridization (FISH). The stability of Wolbachia infections and density was determined by qPCR. qPCR was also used to examine immune genes in the IMD, Toll and JACK/STAT pathways to determine if Wolbachia were associated with an immune response in infected cells. Results Here we have transfected two Culicoides sonorensis cell lines (W3 and W8) with a Wolbachia infection (walbB) from donor Aedes albopictus Aa23 cells. PCR and FISH showed the presence of Wolbachia infections in both C. sonorensis cell lines. Infection densities were higher in the W8 cell lines when compared to W3. In stably infected cells, genes in the immune Toll, IMD and JAK/STAT pathways were upregulated, along with Attacin and an Attacin-like anti-microbial peptides. Conclusions The successful introduction of Wolbachia infections in C. sonorensis cell lines and the upregulation of immune genes, suggest the utility of using Wolbachia for a population replacement and/or population suppression approach to limit the transmission of C. sonorensis vectored diseases. Results support the further investigation of Wolbachia induced pathogen inhibitory effects in Wolbachia-infected C. sonorensis cell lines and the introduction of Wolbachia into C. sonorensis adults via embryonic microinjection to examine for reproductive phenotypes and host fitness effects of a novel Wolbachia infection.

Real-time PCR versus shell vial culture on urine of patients with suspected congenital cytomegalovirus infection

Aims: Cytomegalovirus (CMV) is the most common cause of congenital infection. Aim of this study is to support quantitative real-time polymerase chain reaction (PCR) versus shell vials culture for CMV screening in urine samples. Patients & methods: A retrospective study was conducted on 255 urine samples belonging to patients admitted to Bambino Gesù Pediatric Hospital, Rome, Italy, with suspected congenital CMV infection. Results & conclusion: Quantitative real-time PCR resulted more standardized, faster, less operator-dependent, less laborious and most of all cost saving and more sensitive than shell vial culture. Since a negative result for CMV in urine means no congenital infection, a more sensitive tool for detection of CMV DNA is essential to improve patient management and to reduce healthcare costs associated to a late diagnosis.