Review on Major Food-Borne Zoonotic Bacterial Pathogens

Detoxification of Aflatoxin B1 and Ochratoxin A Using Salvia farinacea and Azadirachta indica Water Extract and Application in Meat Products

Seventy-five samples of selected meat products, including luncheon, beef burger, sausage, basterma, and kofta, were collected from Alexandria and New Borg El-Arab cities (Egypt). The samples were subjected to mycological examination as well as for detection of aflatoxin B1 (AFB1) and ochratoxin A (OTA) residues. Besides, the study evaluated the effect of aqueous leaf extracts from mealycup sage (Salvia farinacea) and neem (Azadirachta indica), individually and in combination, on the growth of human pathogens Aspergillus parasiticus and Aspergillus flavus producing AFB1, as well as Aspergillus ochraceus and Aspergillus niger which produce OTA. The obtained results revealed that sausage samples had the highest mould count with a mean value of 13.20×102/g, followed by basterma samples 12.05×102/g, then beef burger 7.39×102/g. In contrast, luncheon and kofta samples had the lowest count with a mean value of 5.51×102/g and 2.82×102/g. The findings revealed the antifungal potential of tested extracts. The total inhibition of A. parasitcus and A. niger growth was observed at 2 mg/mL of the combined extract. Salvia farinacea extract had the highest total phenolic content and total flavonoid content with a value of 174.1 and 52.6 mg g-1, respectively. Rutin was the major phenolic component in neem and combined extracts, accounting for 19123 and 8882 μg/g, respectively. Besides, the study investigated detoxification of AFB1 and OTA using combined extract in albino rats. The results confirmed the convenient and safe use of Salvia farinacea and Azadirachta indica extract and their combination as natural antifungal and antioxidant agents. The combined extract could be used as a natural preservative in food processing to control or prevent contamination.

The molecular interplay of the establishment of an infection - gene expression of Diaphorina citri gut and Candidatus Liberibacter asiaticus

BACKGROUND

Candidatus Liberibacter asiaticus (CLas) is one the causative agents of greening disease in citrus, an unccurable, devastating disease of citrus worldwide. CLas is vectored by Diaphorina citri, and the understanding of the molecular interplay between vector and pathogen will provide additional basis for the development and implementation of successful management strategies. We focused in the molecular interplay occurring in the gut of the vector, a major barrier for CLas invasion and colonization.

RESULTS

We investigated the differential expression of vector and CLas genes by analyzing a de novo reference metatranscriptome of the gut of adult psyllids fed of CLas-infected and healthy citrus plants for 1-2, 3-4 and 5-6 days. CLas regulates the immune response of the vector affecting the production of reactive species of oxygen and nitrogen, and the production of antimicrobial peptides. Moreover, CLas overexpressed peroxiredoxin, probably in a protective manner. The major transcript involved in immune expression was related to melanization, a CLIP-domain serine protease we believe participates in the wounding of epithelial cells damaged during infection, which is supported by the down-regulation of pangolin. We also detected that CLas modulates the gut peristalsis of psyllids through the down-regulation of titin, reducing the elimination of CLas with faeces. The up-regulation of the neuromodulator arylalkylamine N-acetyltransferase implies CLas also interferes with the double brain-gut communication circuitry of the vector. CLas colonizes the gut by expressing two Type IVb pilin flp genes and several chaperones that can also function as adhesins. We hypothesized biofilm formation occurs by the expression of the cold shock protein of CLas.

CONCLUSIONS

The thorough detailed analysis of the transcritome of Ca. L. asiaticus and of D. citri at different time points of their interaction in the gut tissues of the host led to the identification of several host genes targeted for regulation by L. asiaticus, but also bacterial genes coding for potential effector proteins. The identified targets and effector proteins are potential targets for the development of new management strategies directed to interfere with the successful utilization of the psyllid vector by this pathogen.

Camostat mesilate inhibits pro-inflammatory cytokine secretion and improves cell viability by regulating MFGE8 and HMGN1 in lipopolysaccharide-stimulated DF-1 chicken embryo fibroblasts

Camostat mesilate (CM) possesses potential anti-viral and anti-inflammatory activities. However, it remains unknown whether CM is involved in lipopolysaccharide (LPS)-mediated inflammatory responses and cell injury. In this project, differentially expressed proteins (DEPs, fold change ≥ 1.2 or ≤ 0.83 and Q value ≤ 0.05) in response to LPS stimulation alone or in combination with CM were identified through tandem mass tags (TMT)/mass spectrometry (MS)-based proteomics analysis in DF-1 chicken embryo fibroblasts. The mRNA expression levels of filtered genes were determined by RT-qPCR assay. The results showed that CM alleviated the detrimental effect of LPS on cell viability and inhibited LPS-induced TNF-α and IL-6 secretions in DF-1 chicken embryo fibroblasts. A total of 141 DEPs that might be involved in mediating functions of both LPS and CM were identified by proteomics analysis in DF-1 chicken embryo fibroblasts. LPS inhibited milk fat globule EGF and factor V/VIII domain containing (MFGE8) expression and induced high mobility group nucleosome binding domain 1 (HMGN1) expression, while these effects were abrogated by CM in DF-1 chicken embryo fibroblasts. MFGE8 knockdown facilitated TNF-α and IL-6 secretions , reduced cell viability, stimulated cell apoptosis in DF-1 chicken embryo fibroblasts co-treated with LPS and CM. HMGN1 loss did not influence TNF-α and IL-6 secretions, cell viability, and cell apoptosis in DF-1 chicken embryo fibroblasts co-treated with LPS and CM. In conclusion, CM exerted anti-inflammatory and pro-survival activities by regulating MFGE8 in LPS-stimulated DF-1 chicken embryo fibroblasts, deepening our understanding of the roles and molecular basis of CM in protecting against Gram-negative bacteria.

Prevalence and epidemiological distribution of selected foodborne pathogens in human and different environmental samples in Ethiopia: a systematic review and meta-analysis

Bacterial Foodborne Pathogens (FBP) are the commonest cause of foodborne illness or foodborne diseases (FBD) worldwide. They contaminate food at any stages in the entire food chain, from farm to dining-table. Among these, the Diarrheagenic Escherichia coli (DEC), Non typhoidal Salmonella (NTS), Shigella spp. and Campylobacter spp. are responsible for a large proportion of illnesses, deaths; and, particularly, as causes of acute diarrheal diseases. Though existing studies indicate the problem may be severe in developing countries like Ethiopia, the evidence is commonly based on fragmented data from individual studies. A review of published and unpublished manuscripts was conducted to obtain information on major FBP and identify the gaps in tracking their source attributions at the human, animal and environmental interface. A total of 1753 articles were initially retrieved after restricting the study period to between January 2000 and July 2020. After the second screening, only 51 articles on the humans and 43 on the environmental sample based studies were included in this review. In the absence of subgroups, overall as well as human stool and environmental sample based pooled prevalence estimate of FBP were analyzed. Since, substantial heterogeneity is expected, we also performed a subgroup analyses for principal study variables to estimate pooled prevalence of FBP at different epidemiological settings in both sample sources. The overall random pooled prevalence estimate of FBP (Salmonella, pathogenic Escherichia coli (E. coli), Shigella and Campylobacter spp.) was 8%; 95% CI: 6.5-8.7, with statistically higher (P <  0.01) estimates in environmental samples (11%) than in human stool (6%). The subgroup analysis depicted that Salmonella and pathogenic E. coli contributed to 5.7% (95% CI: 4.7-6.8) and 11.6% (95% CI: 8.8-15.1) respectively, of the overall pooled prevalence estimates of FBD in Ethiopia. The result of meta-regression showed, administrative regional state, geographic area of the study, source of sample and categorized sample size all significantly contributed to the heterogeneity of Salmonella and pathogenic E. coli estimates. Besides, the multivariate meta- regression indicated the actual study year between 2011 and 2015 was significantly associated with the environmental sample-based prevalence estimates of these FBP. This systematic review and meta-analysis depicted FBP are important in Ethiopia though majority of the studies were conducted separately either in human, animal or environmental samples employing routine culture based diagnostic method. Thus, further FBD study at the human, animal and environmental interface employing advanced diagnostic methods is needed to investigate source attributions of FBD in one health approach.

Incidence, Enumeration and Confirmation of Listeria and its Species in Ready-to-eat Street Vended Salads Sold at Various Outlets of Faisalabad City, Pakistan

The desire for a healthy lifestyle and faster mode of preparation has supported the consumption of ready to eat fresh salad. Street vended salads are recognized as a source of pathogenic transamination in different parts of the world. The present study was designed to evaluate the safety status of fresh vegetable and Russian salads being sold at various food outlets of Faisalabad. Samples of freshly prepared salads were collected from representative selected different areas of Faisalabad city divided into four different zones (zone 1, zone 2, zone 3 and zone 4). Prevalence and enumeration of Listeria was done through microbial testing via the spread plate method. Among samples of vegetable salad, highest prevalence of Listeria was found in the zone 2 (75%) whereas Russian salad samples from zones 1 and 3 exhibited 62% prevalence, the highest among all 4 zones of study. On the whole, the lowest prevalence of Listeria was found in zone 4 (50% vegetable salad and 58% Russian salad). Biochemical conformation of Listeria done through different tests for the identification of various Listeria species, exhibited that Listeria monocytogenes and Listeria innocua were highly prevalent in samples from zones 1 and 3 respectively. The results will help to improve safety concerns associated with street vended foods.

Consumer perceptions of food safety in animal source foods choice and consumption in Nairobi's informal settlements

Background

Animal-source foods (ASFs) are high-quality nutrient-dense products key to reducing stunting and micronutrient deficiencies. However, their consumption among the poorest households in urban informal settlements is low. Several drivers beyond price, including health considerations have been reported to drive ASF choice and consumption among consumers. This current study explores consumer perceptions of food safety associated with animal source foods (ASFs) consumption in urban informal settlements with a view to unpacking the health considerations driving their choice and consumption.

Methods

Coupled households with children 6–59 months formed the study sample. The Food Environments Working Group (FEWG) Framework of the Agriculture and Nutrition for Health academy (ANH) was used to guide the study which utilized qualitative methods namely, 60 in-depth interviews (IDIs), 19 focus group discussions, and 19 key informant interviews (KIIs) complemented by unstructured observations. Data were transcribed and analysed according to emerging themes.

Results

Consumer perceptions of food safety are driven by concerns about food production, processing, handling, storage and the health risks associated with consumption of the ASFs. For all the ASFs, lack of traceability of source, unhygienic environments in which they were sold and health risks around consuming too much or improperly cooked products were key perceptions from the community. To mitigate against food safety risks, consumers used strategies such as boiling the ASFs, purchasing their products from trusted retailers, avoiding vendors in unhygienic environments and reducing the amount and frequency of consumption of ASFs or totally avoiding their consumption.

These consumer perceptions are increasingly influencing the ASFs choice and consumption in low-income populations besides other drivers. Notably, given limited incomes that influence their purchasing power and the need for nutritious diets that included ASFs, the dilemma of quality vis-a-vis quantity persists and consumers still accessed and consumed these ASF products to supplement their diets.

Conclusions

To enhance food safety for ASFs, as well as assure consumer access to safe ASFs from informal markets, there is need to contextualize the value chain as informed by consumer perceptions on food safety as these influence their ASFs choice and consumption.

Assessing the efficiency of essential oil and active compounds/poly (lactic acid) microcapsules against common foodborne pathogens

Essential oils' active compounds present great potential as a bactericidal agent in active packaging. The encapsulation in polymeric walls promotes their protection against external agents besides allowing controlled release. This work produced PLA capsules with three different active compounds, Cinnamomum cassia essential oil (CEO), eugenol (EEO), and linalool (LEO), by emulsion solvent evaporation method. Characterizations included SEM, Zeta potential, FTIR, TGA, and bactericidal activity against E. coli, S. aureus, L. monocytogenes, and Salmonella. The active compounds showed microbiological activity against all pathogens. CEO capsules showed superior colloidal stability. The active compounds' presence in all capsules was confirmed by FTIR analysis, with possible physical interaction between CEO, EEO, and the polymeric matrix, while LEO had a possible chemical interaction with PLA. TGA analysis showed a plasticizing effect of active compounds, and the loading efficiency was 39.7%, 50.7%, and 22.3% for CEO-PLA, EEO-PLA, and LEO-PLA, respectively. The capsules presented two release stages, sustaining activity against pathogens for up to 28 days, indicating a satisfactory internal morphology. This study presented methodology for encapsulation of antimicrobial compounds that can be suitable for active food packaging. CEO-PLA capsules regarding stability and antibacterial activity achieved the best results.

Antibiotic resistance patterns of Staphylococcus spp. isolated from fast foods sold in different restaurants of Mymensingh, Bangladesh

OBJECTIVE

Fast foods are often responsible for staphylococcal foodborne illness. The present study was carried out to isolate Staphylococcus spp. from various fast foods sold in Mymensingh and to determine their antibiogram.

MATERIALS AND METHODS

Overall, 60 samples of fast foods sold in different restaurants were screened by culture, biochemical tests, and polymerase chain reaction (PCR) to isolate and identify Staphylococcus spp., followed by employing of disk diffusion method to determine their antibiotic resistance patterns.

RESULTS

Among these 60 samples, 8 [13.33%, 95% confidence interval (CI): 6.91%-24.17%] were positive for Staphylococcus spp. by cultural and biochemical properties. By PCR, four (6.67%, 95% CI: 2.62%-15.93%) isolates were confirmed as Staphylococcus aureus by targeting nuc gene. Additionally, all the S. aureus isolates were coagulase-positive. By antibiogram profiles, all the Staphylococcus isolates exhibited resistance to azithromycin and erythromycin (95% CI: 67.56%-100.00%), and frequently resistance to cefixime (75%, 95% CI: 40.93%-95.56%), ampicillin (50%, 95% CI: 21.52%-78.48%), and amoxicillin (37.5%, 95% CI: 13.68%-69.43%); moderate to lower resistance was found against cefotaxime, gentamicin, and doxycycline. In addition, all the isolates were sensitive to ciprofloxacin and chloramphenicol. Interestingly, 75% (6/8; 95% CI: 40.93%-95.56%) isolates were multidrug-resistant (MDR) in nature. Furthermore, the indices of multiple antibiotic resistance (MAR) were ranged from 0.2 to 0.6.

CONCLUSION

This study revealed that fast foods sold in restaurants were contaminated with MDR and MAR Staphylococcus isolates, having potential public health significance.

ProkEvo: an automated, reproducible, and scalable framework for high-throughput bacterial population genomics analyses

Whole Genome Sequence (WGS) data from bacterial species is used for a variety of applications ranging from basic microbiological research, diagnostics, and epidemiological surveillance. The availability of WGS data from hundreds of thousands of individual isolates of individual microbial species poses a tremendous opportunity for discovery and hypothesis-generating research into ecology and evolution of these microorganisms. Flexibility, scalability, and user-friendliness of existing pipelines for population-scale inquiry, however, limit applications of systematic, population-scale approaches. Here, we present ProkEvo, an automated, scalable, reproducible, and open-source framework for bacterial population genomics analyses using WGS data. ProkEvo was specifically developed to achieve the following goals: (1) Automation and scaling of complex combinations of computational analyses for many thousands of bacterial genomes from inputs of raw Illumina paired-end sequence reads; (2) Use of workflow management systems (WMS) such as Pegasus WMS to ensure reproducibility, scalability, modularity, fault-tolerance, and robust file management throughout the process; (3) Use of high-performance and high-throughput computational platforms; (4) Generation of hierarchical-based population structure analysis based on combinations of multi-locus and Bayesian statistical approaches for classification for ecological and epidemiological inquiries; (5) Association of antimicrobial resistance (AMR) genes, putative virulence factors, and plasmids from curated databases with the hierarchically-related genotypic classifications; and (6) Production of pan-genome annotations and data compilation that can be utilized for downstream analysis such as identification of population-specific genomic signatures. The scalability of ProkEvo was measured with two datasets comprising significantly different numbers of input genomes (one with ~2,400 genomes, and the second with ~23,000 genomes). Depending on the dataset and the computational platform used, the running time of ProkEvo varied from ~3-26 days. ProkEvo can be used with virtually any bacterial species, and the Pegasus WMS uniquely facilitates addition or removal of programs from the workflow or modification of options within them. To demonstrate versatility of the ProkEvo platform, we performed a hierarchical-based population structure analyses from available genomes of three distinct pathogenic bacterial species as individual case studies. The specific case studies illustrate how hierarchical analyses of population structures, genotype frequencies, and distribution of specific gene functions can be integrated into an analysis. Collectively, our study shows that ProkEvo presents a practical viable option for scalable, automated analyses of bacterial populations with direct applications for basic microbiology research, clinical microbiological diagnostics, and epidemiological surveillance.

A comprehensive review on the applications of nano-biosensor-based approaches for non-communicable and communicable disease detection

The outstretched applications of biosensors in diverse domains has become the reason for their attraction for scientific communities. Because they are analytical devices, they can detect both quantitative and qualitative biological components through the generation of detectable signals. In the recent past, biosensors witnessed significant changes and developments in their design as well as features. Nanotechnology has revolutionized sensing phenomena by increasing biodiagnostic capacity in terms of specificity, size, and cost, resulting in exceptional sensitivity and flexibility. The steep increase of non-communicable diseases across the world has emerged as a matter of concern. In parallel, the abrupt outbreak of communicable diseases poses a serious threat to mankind. For decreasing the morbidity and mortality associated with various communicable and non-communicable diseases, early detection and subsequent treatment are indispensable. Detection of different biological markers generates quantifiable signals that can be electrochemical, mass-based, optical, thermal, or piezoelectric. Speculating on the incumbent applicability and versatility of nano-biosensors in large disciplines, this review highlights different types of biosensors along with their components and detection mechanisms. Moreover, it deals with the current advancements made in biosensors and the applications of nano-biosensors in detection of various non-communicable and communicable diseases, as well as future prospects of nano-biosensors for diagnostics.

Harnessing Clinical Trial Capacity to Mitigate Zoonotic Diseases: The Role of Expert Scientists in Ethiopia

Background: The emergence and resurgence of zoonotic diseases have continued to be a major threat to global health and the economy. Developing countries are particularly vulnerable due to agricultural expansions and domestication of animals with humans. Scientifically sound clinical trials are important to find better ways to prevent, diagnose, and treat zoonotic diseases, while there is a lack of evidence to inform the clinical trials' capacity and practice in countries highly affected with the diseases. This study aimed to investigate expert scientists' perceptions and experiences in conducting clinical trials toward zoonotic diseases in Ethiopia.

Methods: This study employed a descriptive, qualitative study design. It included major academic and research institutions in Ethiopia that had active engagements in veterinary and public health researches. It included the National Veterinary Institute, the National Animal Health Diagnostic and Investigation Center, the College of Veterinary Medicine at Addis Ababa University, the Ethiopian Public Health Institute, the Armauer Hansen Research Institute, and the College of Health Sciences at Addis Ababa University. In-depth interviews were conducted with expert scientists. Data were collected from October 2019 to April 2020. Data analysis was undertaken using open code 4.03 for qualitative data analysis.

Results: Five major themes, with 18 sub-themes, emerged from the in-depth interviews. These were: challenges in the prevention, control, and treatment of zoonotic diseases; One Health approach to mitigate zoonotic diseases; personal and institutional experiences in conducting clinical trials on zoonotic diseases; barriers in conducting clinical trials toward zoonotic diseases; and strategies that promote conducting clinical trials on zoonotic diseases. Conducting clinical trials on zoonotic diseases in Ethiopia is hampered by a lack of clearly articulated ethics and regulatory frameworks, trial experts, financial resources, and good governance.

Conclusion: In Ethiopia, conducting clinical trials on zoonotic diseases deserves due attention. Strengthening institutional and human resources capacity is a pre-condition to harness effective implementation of clinical trials on zoonotic diseases in the country. In Ethiopia where skilled human resource is scarce, One Health approach has the potential to form multidisciplinary teams to systematically improve clinical trials capacity and outcomes in the country.

Molecular characterization of Salmonella spp. isolates from river and dam water, irrigated vegetables, livestock, and poultry manures in Jordan

Background and Aim

Salmonellosis is an important food-borne and zoonotic disease with high morbidity and mortality rates. The objectives of this study were to isolate, serotype, and genetically characterize Salmonella spp. from Zarqa river and King Talal dam waters, vegetables irrigated by such waters, and manure of poultry and livestock farms located in the Zarqa river basin in Jordan. In addition, certain virulence factors and antimicrobial resistance patterns of isolated Salmonella strains were determined.

Materials and Methods

A total of 250 samples were cultured using routine microbiological methods. Suspected Salmonella spp. were identified based on colony morphology and confirmed using biochemical and molecular methods. Virulence genes including invA, stn, and pCT plasmid were detected using multiplex PCR. Phylogenetic analysis was performed using pulsed-field gel electrophoresis (PFGE).

Results

In total, 32/250 (12.8%) Salmonella spp. isolates were recovered from different sources. Of these, the most common serotype was Salmonella subspecies 1 (23 isolates), followed by Salmonella enterica serovar Typhimurium (4 isolates), Salmonella enterica serovar Typhi (3 isolates), and finally Salmonella enterica serovar Enteritidis (2 isolates). The PFGE indicated that Salmonella enterica serovar Typhimurium isolated from poultry manure and from parsley were closely related (84.6%). Salmonella enterica serovar Enteritidis isolated from the dam water was closely related to Salmonella enterica serovar Enteritidis isolated from spearmint (73.8%). Salmonella enterica serovar Typhi isolated from the river and dam water were 100% related to Salmonella enterica serovar Typhi isolated from lettuce. In the antimicrobial sensitivity test, 14 out of 32 (43.8%) isolated Salmonella strains were resistant to two or more of the major antimicrobial agent groups. However, the majority of isolates were sensitive to ceftriaxone, ciprofloxacin, cefuroxime, and gentamicin (97%, 93.8%, and 87.5%, 84.4%, respectively). All isolates were resistant to erythromycin and amoxicillin.

Conclusion

Results of this study indicate a serious potential threat to public health associated with consuming leafy green vegetables grown on the banks of Zarqa river and its dam because of widespread Salmonella spp. contamination. Appropriate monitoring of irrigation water must be applied to reduce the possibility of cross-contamination.

Non-Digestible Oligosaccharides and Short Chain Fatty Acids as Therapeutic Targets against Enterotoxin-Producing Bacteria and Their Toxins

Enterotoxin-producing bacteria (EPB) have developed multiple mechanisms to disrupt gut homeostasis, and provoke various pathologies. A major part of bacterial cytotoxicity is attributed to the secretion of virulence factors, including enterotoxins. Depending on their structure and mode of action, enterotoxins intrude the intestinal epithelium causing long-term consequences such as hemorrhagic colitis. Multiple non-digestible oligosaccharides (NDOs), and short chain fatty acids (SCFA), as their metabolites produced by the gut microbiota, interact with enteropathogens and their toxins, which may result in the inhibition of the bacterial pathogenicity. NDOs characterized by diverse structural characteristics, block the pathogenicity of EPB either directly, by inhibiting bacterial adherence and growth, or biofilm formation or indirectly, by promoting gut microbiota. Apart from these abilities, NDOs and SCFA can interact with enterotoxins and reduce their cytotoxicity. These anti-virulent effects mostly rely on their ability to mimic the structure of toxin receptors and thus inhibiting toxin adherence to host cells. This review focuses on the strategies of EPB and related enterotoxins to impair host cell immunity, discusses the anti-pathogenic properties of NDOs and SCFA on EPB functions and provides insight into the potential use of NDOs and SCFA as effective agents to fight against enterotoxins.

Elicitation of Stress-Induced Phenolic Metabolites for Antimicrobial Applications against Foodborne Human Bacterial Pathogens

Foodborne bacterial pathogens in consumed foods are major food safety concerns worldwide, leading to serious illness and even death. An exciting strategy is to use novel phenolic compounds against bacterial pathogens based on recruiting the inducible metabolic responses of plant endogenous protective defense against biotic and abiotic stresses. Such stress-inducible phenolic metabolites have high potential to reduce bacterial contamination, and particularly improve safety of plant foods. The stimulation of plant protective response by inducing biosynthesis of stress-inducible phenolics with antimicrobial properties is among the safe and effective strategies that can be targeted for plant food safety and human gut health benefits. Metabolically driven elicitation with physical, chemical, and microbial elicitors has shown significant improvement in the biosynthesis of phenolic metabolites with antimicrobial properties in food and medicinal plants. Using the above rationale, this review focuses on current advances and relevance of metabolically driven elicitation strategies to enhance antimicrobial phenolics in plant food models for bacterial-linked food safety applications. Additionally, the specific objective of this review is to explore the potential role of redox-linked pentose phosphate pathway (PPP) regulation for enhancing biosynthesis of stress-inducible antibacterial phenolics in elicited plants, which are relevant for wider food safety and human health benefits.

Antimicrobial Resistance in Escherichia coli Strains Isolated from Humans and Pet Animals

Throughout scientific literature, we can find evidence that antimicrobial resistance has become a big problem in the recent years on a global scale. Public healthcare systems all over the world are faced with a great challenge in this respect. Obviously, there are many bacteria that can cause infections in humans and animals alike, but somehow it seems that the greatest threat nowadays comes from the Enterobacteriaceae members, especially Escherichia coli. Namely, we are witnesses to the fact that the systems that these bacteria developed to fight off antibiotics are the strongest and most diverse in Enterobacteriaceae. Our great advantage is in understanding the systems that bacteria developed to fight off antibiotics, so these can help us understand the connection between these microorganisms and the occurrence of antibiotic-resistance both in humans and their pets. Furthermore, unfavorable conditions related to the ease of E. coli transmission via the fecal-oral route among humans, environmental sources, and animals only add to the problem. For all the above stated reasons, it is evident that the epidemiology of E. coli strains and resistance mechanisms they have developed over time are extremely significant topics and all scientific findings in this area will be of vital importance in the fight against infections caused by these bacteria.

Whole Genome Sequence-Based Prediction of Resistance Determinants in High-Level Multidrug-Resistant Campylobacter jejuni Isolates in Lithuania

Spread of antibiotic resistance via mobile genetic elements associates with transfer of genes providing resistance against multiple antibiotics. Use of various comparative genomics analysis techniques enables to find intrinsic and acquired genes associated with phenotypic antimicrobial resistance (AMR) in Campylobacter jejuni genome sequences with exceptionally high-level multidrug resistance. In this study, we used whole genome sequences of seven C. jejuni to identify isolate-specific genomic features associated with resistance and virulence determinants and their role in multidrug resistance (MDR). All isolates were phenotypically highly resistant to tetracycline, ciprofloxacin, and ceftriaxone (MIC range from 64 to ≥256 µg/mL). Besides, two C. jejuni isolates were resistant to gentamicin, and one was resistant to erythromycin. The extensive drug-resistance profiles were confirmed for the two C. jejuni isolates assigned to ST-4447 (CC179). The most occurring genetic antimicrobial-resistance determinants were tetO, beta-lactamase, and multidrug efflux pumps. In this study, mobile genetic elements (MGEs) were detected in genomic islands carrying genes that confer resistance to MDR, underline their importance for disseminating antibiotic resistance in C. jejuni. The genomic approach showed a diverse distribution of virulence markers, including both plasmids and phage sequences that serve as horizontal gene transfer tools. The study findings describe in silico prediction of AMR and virulence genetics determinants combined with phenotypic AMR detection in multidrug-resistant C. jejuni isolates from Lithuania.

A Significant Question in Cancer Risk and Therapy: Are Antibiotics Positive or Negative Effectors? Current Answers and Possible Alternatives

Cancer is predominantly considered as an environmental disease caused by genetic or epigenetic alterations induced by exposure to extrinsic (e.g., carcinogens, pollutants, radiation) or intrinsic (e.g., metabolic, immune or genetic deficiencies). Over-exposure to antibiotics, which is favored by unregulated access as well as inappropriate prescriptions by physicians, is known to have led to serious health problems such as the rise of antibiotic resistance, in particular in poorly developed countries. In this review, the attention is focused on evaluating the effects of antibiotic exposure on cancer risk and on the outcome of cancer therapeutic protocols, either directly acting as extrinsic promoters, or indirectly, through interactions with the human gut microbiota. The preponderant evidence derived from information reported over the last 10 years confirms that antibiotic exposure tends to increase cancer risk and, unfortunately, that it reduces the efficacy of various forms of cancer therapy (e.g., chemo-, radio-, and immunotherapy alone or in combination). Alternatives to the current patterns of antibiotic use, such as introducing new antibiotics, bacteriophages or enzybiotics, and implementing dysbiosis-reducing microbiota modulatory strategies in oncology, are discussed. The information is in the end considered from the perspective of the most recent findings on the tumor-specific and intracellular location of the tumor microbiota, and of the most recent theories proposed to explain cancer etiology on the notion of regression of the eukaryotic cells and systems to stages characterized for a lack of coordination among their components of prokaryotic origin, which is promoted by injuries caused by environmental insults.

Multi-Sample Preparation Assay for Isolation of Nucleic Acids Using Bio-Silica with Syringe Filters

The spin-column system for the isolation of nucleic acids (NAs) from multiple samples presents the inconvenience of repeated experimentation, time-consumption, and the risk of contamination in the process of the spin-column exchange. Herein, we propose a convenient and universal assay that can be used to diagnose multiple pathogens using a multi-sample preparation assay. The multi-sample preparation assay combines a 96-well filter/membrane plate, a bio-micromaterial lattice-like micro amine-functional diatomaceous earth (D-APDMS), and homobifunctional imidoesters (HI) for the processing of pathogen enrichment and extraction for multiple samples simultaneously. The purity and quantity of the extracted NAs from pathogens (E. coli and Brucella) using the proposed assay is superior to that of the commercialized spin-column kit. The assay also does not require the replacement of several collection tubes during the reaction processing. For the multi-sample testing, we used as many as six samples simultaneously with the proposed assay. This assay can simultaneously separate up to 96 NAs from one plate, and the use of multichannel pipettes allows faster and simpler experimentation. Therefore, we believe it is a convenient and easy process, and can be easily integrated with other detection methods for clinical diagnostics.