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European Journal of Microbiology and Immunology
Authors:
Lynn Glyschewski
,
Andreas Hahn
,
Holger Rohde
,
Marc Lütgehetmann
,
Torsten Feldt
,
Fred Stephen Sarfo
,
Richard Odame Phillips
,
Albert Dompreh
,
Shadrack Osei Asibey
,
Richard Boateng
,
Felix Weinreich
,
Hagen Frickmann
, and
Kirsten Alexandra Eberhardt

Abstract

Background

The study assessed replicative human immunodeficiency virus-(HIV-) infection and replicative co-infections as well as molecular determinants of reduced susceptibility towards anti-retroviral therapy in a Ghanaian population of known HIV patients and a control group.

Methods

Real-time PCRs for HIV-1, HIV-2, hepatitis B virus (HBV) and hepatitis C virus (HCV) were run with serum samples from known Ghanaian HIV-patients (n = 975) and control individuals (n = 105). For 108 individuals, HIV-sequence analysis was performed.

Results

Prevalence of replicative HIV-1 infection was 59.8% (583/975) in the known HIV-positive population and 2.9% (3/105) in the controls. Prevalences of replicative HBV-infection were comparable with 3.4% (33/975) in the HIV-positive individuals and 3.8% (4/105) in the controls. HIV-2 and HCV sequences were not recorded. Almost perfect concordance between two compared HIV-1-PCR assays was indicated by Fleiss' Kappa >0.8. Sanger sequencing indicated CRF_02AG, G and A3 as the quantitatively dominating HIV-1 subtypes, a minority of 3.4% CXCR4 tropism and high detection rates of mutations mediating reduced susceptibility towards nucleoside reverse transcriptase inhibitors (71.9%, 64/89), non-nucleoside reverse transcriptase inhibitors (95.5%, 85/89), protease inhibitors (95.9%, 93/97) and integrase inhibitors (22.4%, 22/98).

Conclusions

The assessment did not suggest HIV-triggered increased replication of HBV and HCV in the investigated Ghanaian population.

Open access

Abstract

The number of human infections with multidrug-resistant (MDR) bacteria is increasing worldwide and constitutes a serious threat to human health. Given the lack of novel antibiotic compounds worsening this dilemma, alternative antibiotic-independent treatment and prevention strategies of infectious diseases applying natural compounds appear highly appreciable. Given the long-known health-beneficial and disease-alleviating properties of Cannabis, we performed a literature search summarizing current knowledge regarding the antibacterial effects of extracts from different parts of the Cannabis sativa plant and of defined Cannabis-derived molecules and their potential mode of action. The included studies revealed that various extracts and essential oils of C. sativa as well as major cannabinoids exerted potent activities against a broad spectrum of Gram-positive bacteria and against some Gram-negative bacterial species including MDR strains. Particularly the disruption of the bacterial cytoplasmic membrane by some cannabinoids resulted in potent antibacterial effects against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus. Furthermore, defined cannabinoids inhibited the formation of and eradicated existing bacterial biofilms. In conclusion, given their antibacterial properties distinct Cannabis-derived molecules expand the repertoire of antibiotics-independent treatment options in the combat of bacterial infectious diseases which should be further addressed in future studies including clinical trials.

Open access
European Journal of Microbiology and Immunology
Authors:
Vanessa Navabi
,
Dorothea Franziska Wiemer
,
Matthias Halfter
,
Ulrich Müseler
,
Susann Dupke
,
Anja Petrov-Salzwedel
,
Ulrich Schotte
, and
Hagen Frickmann

Abstract

Background

The exploratory study assessed trends in the abundance of CTX-M-type extended spectrum beta-lactamase (ESBL) and vancomycin-resistance genes vanA and vanB in the stool samples of German soldiers and police officers returning from predominantly tropical deployments next to the common diarrheagenic Escherichia (E.) coli pathovars enteropathogenic Escherichia coli (EPEC), enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC)) as well as rarely imported Vibrio spp. between 2006 and 2024.

Methods

Surveillance was performed applying real-time polymerase chain reaction and results were stratified by World Health Organization region of deployment as well as by deployment period. For the latter, the study interval was divided into three pre-COVID-19-pandemic periods, the COVID-19-pandemic period and the post-COVID-19-pandemic period. Averaged prevalences were used as references.

Results

In stool samples of 1817 deployed German soldiers and 117 police officers, averaged prevalences were 47.9% and 24.8% for the ESBL-type beta-lactamase bla CTX-M, 30.2% and 14.5% for vanB, 9.0% and 17.9% for EPEC, 3.4% and 12.8% for ETEC, 4.0% and 3.4% for EAEC as well as 2.0% and 3.4% for Vibrio spp., respectively. While resistance genes peaked during early deployments, maximum prevalences for enteropathogens were seen later.

Conclusions

The assessment suggested time- and region-dependence of the assessed parameters.

Open access
Progress in Agricultural Engineering Sciences
Authors:
Szabolcs Homolya
,
Eszter Vozáry
,
Katalin Badak Kerti
,
Tímea Kaszab
,
Mohsen Mardani
, and
Anikó Lambert Meretei

Abstract

In the confectionery industry large quantities of palm fat in the fillings of chocolate products are used. Based on today's nutritional science results, it is desirable to replace palm oil with healthier fats. Oleogels can provide a kind of solution for this replacement. In our work the rheological, textural and thermal properties of oleogels containing high oleic sunflower oil, beeswax and monoglycerides were determined. In the samples we examined, the gelator concentrations were: 20% beeswax, 15% beeswax and 5% monoglyceride, 10% beeswax and 10% monoglyceride, 5% beeswax and 15% monoglyceride, and 20% monoglyceride. Based on our results, the oleogel containing 15% beeswax and 5% monoglyceride seems an eutectic crystal of beeswaxes and monoglyceride. It has relative high hardness, high storage modulus and high viscosity therefore it can replace the Chocofill filling fat, which contains mainly palm fat, used in large quantities in sweets.

Open access

Abstract

Introduction

Allergic contact dermatitis of the feet is a significant problem that affects the quality of life and requires attention from the medical community due to the number of studied and still unidentified allergens. The purpose of this review article is to summarize the available scientific data regarding the most common allergens that cause ACD of the feet.

Methods

Nickel sulphate, neomycin sulphate, thiuram mix and colophony occupy a significant place in the prevalence of allergies. The prevalence of sensitization to rubber and leather products can vary depending on the ethno-demographic characteristics of the country, as well as the specifics of a person's professional activity, such as the use of protective waterproof shoes, increased humidity of the microclimate, and atopy in anamnesis.

Results

Patch testing has been shown to be an important method for identifying allergens, however, not all footwear components are tested during patch testing with standard allergen series, requiring the use of patches made from patient shoe samples.

Conclusions

Expanding the scope of patch testing to include other possible allergens is important for the accurate diagnosis of ACD of the feet and a more detailed study of those allergens that were previously considered rare.

Open access
European Journal of Microbiology and Immunology
Authors:
Juan Diego Ribeiro de Almeida
,
Raissa Sayumy Kataki Fonseca
,
Naira Sulany Oliveira de Sousa
,
Ana Cláudia Alves Cortez
,
Emerson Silva Lima
,
Juliana Gomes de Souza Oliveira
,
Érica Simplício de Souza
,
Hagen Frickmann
, and
João Vicente Braga de Souza

Abstract

Background

The rising prevalence of fungal infections and challenges such as adverse effects and resistance against existing antifungal agents have driven the exploration of new antifungal substances.

Methods

We specifically investigated naphthoquinones, known for their broad biological activities and promising antifungal capabilities. It specifically examined the effects of a particular naphthoquinone on the cellular components of Candida albicans ATCC 60193. The study also assessed cytotoxicity in MRC-5 cells, Artemia salina, and the seeds of tomatoes and arugula.

Results

Among four tested naphthoquinones, 2,3-DBNQ (2,3-dibromonaphthalene-1,4-dione) was identified as highly effective, showing potent antifungal activity at concentrations between 1.56 and 6.25 μg mL−1. However, its cytotoxicity in MRC-5 cells (IC50 = 15.44 µM), complete mortality in A. salina at 50 μg mL−1, and significant seed germination inhibition suggest limitations for its clinical use.

Conclusions

The findings indicate that primary antifungal mechanism of 2,3-DBNQ might involve disrupting fungal membrane permeability, which leads to increased nucleotide leakage. This insight underscores the need for further research to enhance the selectivity and safety of naphthoquinones for potential therapeutic applications.

Open access

Abstract

Tigecycline-resistant Acinetobacter baumannii (TRAB) is increasing in Thailand, complicating antibiotic treatment due to limited antibiotic options. The specific resistance mechanism behind tigecycline resistance is still unclear, necessitating further investigation. We investigated the presence of OXA-type carbapenemases, the antimicrobial susceptibility profile, the inhibitory effect of carbonyl cyanide m-chlorophenylhydrazone (CCCP) on tigecycline susceptibility, the expression levels of RND-type efflux pumps and amino acid substitutions within a two-component regulatory system on 30 Thai clinical isolates. Our investigation revealed that most of (73.3%) TRAB isolates expressed at least one member of the Ade efflux pumps. The ade B was most frequently expressed (63.3%), followed by ade R (50%), ade S (43.3%), ade J (30%) and ade G (10%). Overexpression of the AdeABC was associated with increased tigecycline minimum inhibitory concentrations (MICs) and amino acid substitutions within the AdeRS. Notably, isolates harbouring simultaneous mutations in these genes exhibited an increase in the transcription level of the ade B. Our findings highlight the significant role of the AdeABC system in tigecycline resistance among Thai clinical TRAB isolates. This is supported by point mutations within the AdeRS and upregulated expression of the ade B. These results provide valuable insights for understanding resistance mechanisms and developing novel therapeutic strategies.

Open access

Abstract

The present work aimed to study the yeast communities of whole crop corn silages (CS) that were previously contaminated with aflatoxin-producing Aspergillus flavus (CSCA). In addition, the effect of lactic acid bacterium (LAB) inoculation on the aflatoxin B1 (AFB1) content, genotoxicity, yeast load, and diversity of yeast communities were also investigated. In A. flavus contaminated silages, after two months, the AFB1 content was 40% lower with LAB inoculation, also a lower level of genotoxicity was determined. The number of yeasts cultured from the initial mixture of chopped whole crop corn was 4.8 × 107 CFU g−1 wet mass, while only 2.4 × 106 CFU g−1 from the CSCA and 7.1 × 105 CFU g−1 from the LAB-inoculated CSCA could be cultured. Based on 144 randomly isolated strains, the yeast community of the initial mixture consisted of 8 species. In contrast, the yeast community of CSCA consisted only of 4 species determined by 132 randomly selected isolates. LAB-inoculated CSCA consisted also of 4 species based on 158 randomly isolated strains. Saccharomyces cerevisiae and Pichia kudriavzevii proved to be predominant in the CSCA, while S. cerevisiae and Meyerozyma guilliermondii were the most abundant in the LAB-inoculated CSCA. The species richness was also confirmed by alpha diversity values (1.827, 1.188, and 1.123 as Shannon's indices for CS, CSCA, and LAB-inoculated CSCA, respectively). In response to LAB inoculation, the species diversity decreased considerably.

Open access

Abstract

This study aims to predict drought periods affecting the Tokaj-Hegyalja wine region and the application of this in crop protection. The Tokaj-Hegyalja wine region is the only closed wine region in Hungary with a specific mesoclimate and a corresponding wine grape variety composition, in which climate change strongly threatens cultivation. The probability that a randomly selected day in the vegetation period will fall into a drought period in the future was estimated using the daily precipitation amount and daily maximum temperature data from the Hungarian Meteorological Service for the period 2002–2020. The Markov model, a relatively new mathematical method for the statistical investigation of weather phenomena, was used for this. Markov chains can, therefore, be a valuable tool for organizing integrated pest management. This can be used to plan irrigation, control fungal pathogens infecting the vines, and plan the success of a given vintage.

Open access