Penicillium commune, a mold frequently found on dry-cured meat products, is able to synthesize the mycotoxin cyclopiazonic acid (CPA). To evaluate the hazard due to CPA on such foods, the ability of P. commune to grow and produce CPA at water activities (a(w)) in the range of 0.99 to 0.90 with a meat extract-based medium from 12 to 30 degrees C was determined. CPA was quantified by high-pressure liquid chromatography and mass spectrometry. P. commune was able to grow at every a(w) and temperature tested. The optimal environmental conditions for growth were 20 to 25 degrees C, at 0.97 to 0.96 a(w), but the highest amount of CPA was produced at 30 degrees C, 0.96 a(w). No direct correlation between growth rate and CPA production was assessed. Temperature seems to be the most important factor influencing CPA production. However, there was an interaction between temperature and a(w) that significantly (P < 0.001) affected growth and CPA production. An a(w) of 0.90 had a marked effect, depressing growth and CPA production. Meat extract-based medium proved to be an appropriate substrate for CPA biosynthesis by P. commune under a wide range of conditions.

IntroductionGenomic analysis of hepatitis B virus (HBV) identifies phylogenetic variants, which may lead to distinct biological and clinical behaviors. The satellite hepatitis D virus (HDV) may also influence clinical outcomes in patients with hepatitis B. The aim of this study was to investigate HBV genetic variants, including clinically relevant mutations, and HDV infection in acute and chronic hepatitis B patients in central Argentina.MethodsA total of 217 adult HBV infected patients [acute (AHB): n = 79; chronic (CHB): n = 138] were studied; 67 were HBV/human immunodeficiency virus (HIV) coinfected. Clinical and demographic data were obtained from medical records. Serological markers were determined. Molecular detection of HBV and HDV was carried out by RT-Nested PCR, followed by sequencing and phylogenetic analysis.ResultsOverall, genotype (gt) F [sub-genotype (sgt) F1b] was the most frequently found. In AHB patients, the gts/sgts found were: F1b (74.7%) &gt; A2 (13.9%) &gt; F4 (7.6%) &gt; C (2.5%) &gt; A1 (1.3%). Among CHB patients: F1b (39.1%) &gt; A2 (23.9%) &gt; F4 (18.2%) &gt; D (9.4%) &gt; C and F6 (3.6% each) &gt; A1, A3 and B2 (0.7% each). The distribution of sgt A2 and gt D was significantly different between HBV mono and HBV/HIV coinfected patients [A2: 15.9% vs. 35.7% (p &lt; 0.05), respectively and D: 14.6% vs. 1.8% (p &lt; 0.05), respectively]. Mutation frequency in basal core promoter/pre-Core (BCP/pC) region was 35.5% (77/217) [AHB: 20.3% (16/79), CHB: 44.2% (61/138)]. In the open reading frame (ORF) S, mutations associated with vaccine escape and diagnostic failure were detected in 7.8% of the sequences (17/217) [AHB: 3.8% (3/79), CHB: 10.1% (14/138)]. ORF-P amino acid substitutions associated with antiviral resistance were detected in 3.2% of the samples (7/217) [AHB: 1.3% (1/79), CHB 4.3%, (6/138)]. The anti-HDV seropositivity was 5.2% (4/77); one sample could be sequenced, belonging to gt HDV-1 associated with sgt HBV-D3.DiscussionWe detected an increase in the circulation of genotype F in Central Argentina, particularly among AHB patients, suggesting transmission advantages over the other genotypes. A low rate of mutations was detected, especially those with antiviral resistance implications, which is an encouraging result. The evidence of HDV circulation in our region, reported for the first time, alerts the health system for its search and diagnosis.

The fungal protease EPg222 obtained from Penicillium chrysogenum Pg222 isolated from dry-cured ham, was assayed for proteolytic activity in a meat model system based on sterile pieces of pork loins for 32 days. Treated samples showed a significative reduction of total high ionic strength-soluble proteins during the incubation period, as compared with a control incubated without enzyme, both on the surface and in the depth. SDS-PAGE analysis of this protein fraction showed higher hydrolysis of the main myofibrillar proteins H-meromyosin, actin, and tropomyosin in treated samples. Non-protein and amino acidic nitrogen were detected in higher amounts in enzyme-added than in control pieces of loins, both on the surface and in the depth. Thus, addition of enzyme EPg222 to whole pieces of meat results in an increase of protein hydrolysis. The effect of this enzyme could be of great interest for stimulating proteolysis in whole dry-cured meat pieces.