Postmortem interval assessment by MALDI-TOF mass spectrometry analysis in murine cadavers

Aims

This study assessed the use of matrix‐assisted laser desorption/ionization time of flight (MALDI‐TOF) mass spectrometry as an alternative method to identify species associated with the thanatomicrobiota and epinecrotic communities.

Methods and Results

The study was conducted on 10 murine cadavers, and microbiological swabs were collected from five external anatomical sites (eyes, ears, nose, mouth and rectum) and four internal organs (brain, spleen, liver, heart), during 16 and 30 days, for the thanatomicrobiota and epinecrotic communities, respectively. Our results revealed that the postmortem microbiota associated with the external cavities showed changes over time and reduced taxonomic diversity. The internal organs, initially sterile, showed signs of microbial invasion at 3 and 10 days postmortem for the liver‐spleen and heart‐brain, respectively. The postmortem microbiota was mainly dominated by Firmicutes and Proteobacteria.

Conclusions

MALDI‐TOF is a promising method for estimating postmortem interval (PMI), associated with rapid sample handling, good reproducibility and high productivity.

Significance and Impact of the Study

This study investigated microbial changes during the decomposition process and proposed a simple strategy for PMI estimation. Results introducing the application of the MALDI‐TOF method in the field of forensic.

Campylobacter jejuni bacteremia in Italian pediatric patients with acute lymphoblastic leukemia: Report of two cases

Infections caused by Campylobacter jejuni are rarely associated with extraintestinal complications. C. jejuni bacteremia is difficult to detect in patients with hematological malignancies undergoing chemotherapy where the choice of appropriate antibiotic treatment is extremely important. We report two cases of C. jejuni bacteremia in Italian pediatric patients affected by acute lymphoblastic leukemia (ALL). Agreeing with the most recent epidemiological data, both clinical isolates showed a typical phenotypic antimicrobial resistance patterns with combined resistance to ciprofloxacin and tetracycline. To our knowledge, this is the first report of C. jejuni isolation from the blood of ALL pediatric patients in Italy, and it provides important epidemiological information on this rare infection.

Dissecting the prevention of estrogen-dependent breast carcinogenesis through Nrf2-dependent and independent mechanisms

Breast cancer is the most common malignancy among women worldwide. Various studies indicate that prolonged exposure to elevated levels of estrogens is associated with development of breast cancer. Both estrogen receptor-dependent and independent mechanisms can contribute to the carcinogenic effects of estrogens. Among them, the oxidative metabolism of estrogens plays a key role in the initiation of estradiol-induced breast cancer by generation of reactive estrogen quinones as well as the associated formation of oxygen free radicals. These genotoxic metabolites can react with DNA to form unstable DNA adducts which generate mutations leading to the initiation of breast cancer. A variety of endogenous and exogenous factors can alter estrogen homeostasis and generate genotoxic metabolites. The use of specific phytochemicals and dietary supplements can inhibit the risk of breast cancer not only by the modulation of several estrogen-activating enzymes (CYP19, CYP1B1) but also through the induction of various cytoprotective enzymes (eg, SOD3, NQO1, glutathione S-transferases, OGG-1, catechol-O-methyltransferases, CYP1B1A, etc.) that reestablish the homeostatic balance of estrogen metabolism via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent and independent mechanisms.

Distribution of Hepatitis C Virus Genotypes and Subtypes in the Metropolitan Area of Naples, Italy, in the Era of Interferon-Free Regimens

AIMS

The objective of this work was to study the distribution of hepatitis C virus (HCV) genotypes and subtypes from 2010 to 2015 in 1,221 anti-HCV/HCV-RNA-positive specimens from patients living in the metropolitan area of Naples, since HCV genotypes and subtypes remain cornerstones in the management of chronic HCV infection even in the directly acting antivirals era.

METHODS

The study was carried out on 1,221 anti-HCV/HCV-RNA-positive plasma samples collected between April 2010 and December 2015.

RESULTS

Of the 1,221 patients enrolled, 633 (51.9%) were males and 588 (48.1%) were females, with a mean age of 60 ± 13 (SD) years. The most frequent HCV genotype observed was genotype 1 (68.1%; 1b in 55.3% and 1a in 9.5%); HCV genotype 2 was found in 289 samples (23.67%), genotype 3 in 6.47%, genotype 4 in only 19 samples, and only 2 samples were classified as genotype 5. The mean age of the patients with genotype 1a or 3 was lower (51 ± 12 and 49 ± 12 years, respectively) than those with genotype 1b (62 ± 11, p < 0.0001 for both) or 2 (62 ± 14, p < 0.0001 for both).

CONCLUSIONS

The data from the present study suggest that HCV genotype 1b remains the most prevalent in this area, followed by genotype 2, 1a, and 3a.

Immigrants living in an urban milieu with sanitation in Southern Italy: persistence and transmission of intestinal parasites

In the current era of globalization, the massive movement of populations to developed countries causes a greater attention to neglected tropical diseases in places where such diseases are considered unusual. The present study was planned to assess the persistence of intestinal parasitosis in immigrants stably living in the urban central area of Naples (Southern Italy) and the spread of infection within households with a lifestyle similar to that of the country of origin. A total of 2150 stool samples were analysed with the FLOTAC dual technique, and 415 subjects (19.3 %) tested positive for pathogenic intestinal parasites. One hundred ninety-six subjects were randomly selected and monitored again after 1 year in order to evaluate the persistence of intestinal parasites in immigrants having access to proper sanitation. No pathogenic parasites were found in these 196 samples. A total of 482 cohabitants of 151 positive subjects were recruited to evaluate the interfamilial spread of the identified parasites. Only in 18 households were there subjects infected with the same parasite. Monitoring of parasites in stool samples of immigrants showed a decrease of almost all pathogenic species over the years. From the analysis of households, it is not possible to assert that there is a familial transmission. Our study provides evidence that the prevalence of parasitic infections in immigrants is likely related to the poor sanitary habits of the country of origin and that acquisition of new sanitary regulations, together with the administration of pharmacological treatment, limits the transmission in the households and in the local population of their destination.

Microbe-host interactions: structure and role of Gram-negative bacterial porins

Gram negative bacteria have evolved many mechanisms of attaching to and invading host epithelial and immune cells. In particular, many outer membrane proteins (OMPs) are involved in this initial interaction between the pathogen and their host. The outer membrane (OM) of Gram-negative bacteria performs the crucial role of providing an extra layer of protection to the organism without compromising the exchange of material required for sustaining life. The OM, therefore, represents a sophisticated macromolecular assembly, whose complexity has yet to be fully elucidated. This review will summarize the structural information available for porins, a class of OMP, and highlight their role in bacterial pathogenesis and their potential as therapeutic targets. The functional role of porins in microbe-host interactions during various bacterial infections has emerged only during the last few decades, and their interaction with a variety of host tissues for adhesion to and invasion of the cell and for evasion of host-defense mechanisms have placed bacterial porins at the forefront of research in bacterial pathogenesis. This review will discuss the role that porins play in activating immunological responses, in inducing signaling pathways and their influence on antibiotic resistance mechanisms that involve modifications of the properties of the OM lipid barrier.

Microbe-host interactions: structure and role of Gram-negative bacterial porins

Gram negative bacteria have evolved many mechanisms of attaching to and invading host epithelial and immune cells. In particular, many outer membrane proteins (OMPs) are involved in this initial interaction between the pathogen and their host. The outer membrane (OM) of Gram-negative bacteria performs the crucial role of providing an extra layer of protection to the organism without compromising the exchange of material required for sustaining life. The OM, therefore, represents a sophisticated macromolecular assembly, whose complexity has yet to be fully elucidated. This review will summarize the structural information available for porins, a class of OMP, and highlight their role in bacterial pathogenesis and their potential as therapeutic targets. The functional role of porins in microbe-host interactions during various bacterial infections has emerged only during the last few decades, and their interaction with a variety of host tissues for adhesion to and invasion of the cell and for evasion of host-defense mechanisms have placed bacterial porins at the forefront of research in bacterial pathogenesis. This review will discuss the role that porins play in activating immunological responses, in inducing signaling pathways and their influence on antibiotic resistance mechanisms that involve modifications of the properties of the OM lipid barrier.