Clostridium perfringens-Opportunistic Foodborne Pathogen, Its Diversity and Epidemiological Significance

The C. perfringens species is associated with various environments, such as soils, sewage, and food. However, it is also a component of the gastrointestinal (GI) microflora (i.e., microbiota) of sick and healthy humans and animals. C. perfringens is linked with different systemic and enteric diseases in livestock and humans, such as gas gangrene, food poisoning, non-foodborne diarrhoea, and enterocolitis. The strains of this opportunistic pathogen are known to secrete over 20 identified toxins that are considered its principal virulence factors. C. perfringens belongs to the anaerobic bacteria community but can also survive in the presence of oxygen. The short time between generations, the multi-production capability of toxins and heat-resistant spores, the location of many virulence genes on mobile genetic elements, and the inhabitance of this opportunistic pathogen in different ecological niches make C. perfringens a very important microorganism for public health protection. The epidemiological evidence for the association of these strains with C. perfringens-meditated food poisoning and some cases of non-foodborne diseases is very clear and well-documented. However, the genetic diversity and physiology of C. perfringens should still be studied in order to confirm the importance of suspected novel virulence traits. A very significant problem is the growing antibiotic resistance of C. perfringens strains. The aim of this review is to show the current basic information about the toxins, epidemiology, and genetic and molecular diversity of this opportunistic pathogen.

Probiotic Potential of Clostridium spp.-Advantages and Doubts

Clostridium spp. is a large genus of obligate anaerobes and is an extremely heterogeneous group of bacteria that can be classified into 19 clusters. Genetic analyses based on the next-generation sequencing of 16S rRNA genes and metagenome analyses conducted on human feces, mucosal biopsies, and luminal content have shown that the three main groups of strict extremophile anaerobes present in the intestines are Clostridium cluster IV (also known as the Clostridium leptum group), Clostridium cluster XIVa (also known as the Clostridium coccoides group) and Bacteroides. In addition to the mentioned clusters, some C. butyricum strains are also considered beneficial for human health. Moreover, this bacterium has been widely used as a probiotic in Asia (particularly in Japan, Korea, and China). The mentioned commensal Clostridia are involved in the regulation and maintenance of all intestinal functions. In the literature, the development processes of new therapies are described based on commensal Clostridia activity. In addition, some Clostridia are associated with pathogenic processes. Some C. butyricum strains detected in stool samples are involved in botulism cases and have also been implicated in severe diseases such as infant botulism and necrotizing enterocolitis in preterm neonates. The aim of this study is to review reports on the possibility of using Clostridium strains as probiotics, consider their positive impact on human health, and identify the risks associated with the expression of their pathogenic properties.

Enterococci-Involvement in Pathogenesis and Therapeutic Potential in Cancer Treatment: A Mini-Review

Enterococcus spp. are Gram-positive, heterogeneous lactic acid bacteria inhabiting various environments. Several species of Enterococci are considered to be able to stimulate the immune system and play an important role in intestinal homeostasis. Some Enterococci can be used as probiotics. Some strains of E. faecium are components of pharmaceutical products used to treat diarrhea, antibiotic-associated diarrhea, or irritable bowel syndrome (IBS). However, it has been proved that they are responsible for food contamination, and are sometimes undesirable from the point of view of food technology. Additionally, the virulence and multi-drug resistance of Enterococci potentially pose a risk of an epidemic, especially in hospital environments. Moreover, there are indications of their negative role in colon tumorigenesis; however, some nterococci are proved to support immunotherapy in cancer treatment. In general, it can be concluded that this group of microorganisms, despite its nature, has properties that can be used to support cancer treatment—both aggressive chemotherapy and cutting-edge therapy targeting immune checkpoints (IC).

Effect of heat treatments on the physicochemical and sensory properties of the longissimus thoracis muscle in unweaned Limousin calves

The aim of the study was to assess the effect of methods of heat treatment on selected quality parameters of longissimus thoracis muscle of Limousin calves, subjected to grilling, steaming, and sous vide cooking. The type of heat treatment did not significantly affect shear force or water activity. Cooking loss in the grilled and steamed meat was significantly higher than in the sous vide. While the content of vitamin E was significantly lower in the cooked meat, it was retained to the greatest degree in the grilled meat and least in the steamed meat. The TBARS index significantly increased during all cooking methods with the highest level in steamed meat. The sensory analysis revealed a preference for the sous vide and grilled meat, while the steamed meat received the lowest scores. Although veal is commonly assumed to be highly nutritious and palatable, its quality can be significantly influenced by the type of heat treatment.

Botulinum toxin in cancer therapy-current perspectives and limitations

Abstract

Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle spasms or movement disorders, and, for the two last decades, more and more often, to provide support in cancer therapy, especially so as to obtain analgesic effects upon spastic conditions. The limited literature data also suggests that the addition of BoNTs to the culture of cancer cell lines reduces cell growth, and mitotic activity, and promotes their apoptosis. BoNTs have several advantages that can be emphasized: BoNTs act on both perfusion and oxygenation; moreover, BoNTs are considered to be safe and free of systemic side effects upon administration. Recently, advances in molecular biology techniques have allowed a wide variety of novel BoNT constructs with alternative functions. These constructs could be assessed as potential new classes of anti-cancer drugs. This creates new potential perspectives in the wider use of non-toxic modified BoNT constructs in cancer therapy. In the light of the mentioned premises and existing literature reports, the aim of this review is to summarize current data and reports considering BoNT use in cancer therapy.

Key points

•Botulinum toxin (BoNTs) may be useful in cancer treatment.

•Botulinum toxin can serve as an analgesic after cancer radiotherapy.

•Botulinum toxin has the ability to inhibit tumor growth and promote apoptosis of neoplastic cells.

Clostridium botulinum spores in Polish honey samples

The aim of this study was an examination of 240 multifloral honey samples collected from Polish apiaries to determine Clostridium botulinum occurrence. Honey was collected from apiaries directly after the extraction process. Samples were inoculated by using the dilution and centrifugation method. Suspected isolates were examined by using mouse bioassay, polymerase chain reaction (PCR), and real-time PCR methods. C. botulinum type A and B strains were detected in 5 of 240 examined honey samples (2.1%). Bacterial strains were also detected that were phenotypically similar to C. botulinum but that did not exhibit the ability to produce botulinum toxins and did not show the presence of the botulinum cluster (ntnh and bont genes) or expression of the ntnh gene. The methods used in the examination, especially the expression analysis of ntnh gene, enabled specific analysis of suspected strains and could be used routinely in environmental isolate analyses of C. botulinum occurrence.

Prevalence of C. Botulinum and C. Perfringens Spores in Food Products Available on Polish Market

Introduction

The aim of this study was to evaluate the prevalence of Clostridium botulinum and Clostridium perfringens in food samples purchased from Polish producers.

Material and Methods

The analyses were performed on 260 food samples collected in Lublin and Subcarpathian regions: 56 of smoked meat, 21 of pork meat, 20 of dairy products, 26 of vegetable and fruit preserves, 40 of ready-to-eat meals, 27 of fish preserves, and 70 of honey collected directly from apiaries.

Results

C. botulinum strains were isolated from 2.3% (6/260) of samples and the isolates were classified as toxin types A (4/260) and B (2/260). C. perfringens strains were isolated from 14% (37/260) of samples. All the isolates were classified as toxin type A, 28 of them were able also to produce α toxin and 9 – β2 toxin.

Conclusion

On the basis of the obtained results it could be suggested that risk assessment, especially regarding the entire honey harvesting process, should be provided in order to ensure the microbiological safety of the products to be consumed by infants and people with a weakened immune system.

Molecular diversity of Clostridium botulinum and phenotypically similar strains

This study was undertaken to examine phenotypic and genetic features of strains preliminary classified as Clostridium botulinum species. The phenotypic characteristics were assessed with different culture media and biochemical tests. The genetic characterization included detection of botulinum toxin genes by PCR and macrorestriction analysis with SmaI, XhoI and SacII by PFGE (Pulsed-field Gel Electrophoresis). Despite similar biochemical properties of all analysed strains, only 47% of them contained genes determining toxicity specific to C. botulinum species. The most valuable differentiation of C. botulinum and C. botulinum-like strains was obtained after SmaI digestion. The highest affinity was observed among C. botulinum type B profiles which was even up to 100%. It was found 100% of affinity between C. botulinum and C. botulinum-like strains, however, the similarity among C. botulinum and C. botulinum-like was generally lower than 80%.

Optimisation of protocol for Clostridium botulinum detection in mink feed

As the test material mink feed with natural microflora was used. The analyses were conducted using Wrzosek and TPGY broth media, and Willis–Hobbs and Zeissler differential agar media. Wrzosek, Willis–Hobbs, and Zeissler media are described in Polish Standards approved by the National Standards Body in Poland and routinely used in detection of anaerobic bacteria in Poland. Detection and identification of C. botulinum was performed with a previously validated real-time PCR method based on ntnh gene detection, which is common in all C. botulinum toxotypes. The use of Wrzosek broth and Zeissler agar in routine analyses for detection and identification of C. botulinum was ineffective and limited. The obtained results showed the highest culturing process effectiveness in TPGY broth with 72 h incubation at 30°C and isolation on Willis–Hobbs agar. The real-time PCR method based on ntnh gene detection used in this study could be utilised as a supplementary tool to the mouse lethality assay.

Contamination of honey produced in the Republic of Kazakhstan with Clostridium botulinum

The paper presents the first results of a study on the contamination of honey produced in the Republic of Kazakhstan with C. botulinum spores known to pose a potential infection threat to infants. During microbiological analysis, culturing methods with TPGY, Willis-Hobbs agar, FAA agar connected with PCR, sequencing, and a mouse bioassay were used. The C. botulinum contamination rate of honey was relatively low as determined, at 0.91%. Nonetheless, the potential danger of the bacteria to childrens’ health should not be neglected

The first case of a major avian type C botulism outbreak in Poland

Major outbreaks of avian type C botulism have been rarely reported from Central Europe. In this paper, we report the first severe outbreak of avian type C botulism in Poland. In 2011-12, two epizootics caused by Clostridium botulinum took place at Jeziorsko dam reservoir and affected an estimated number of 5500 birds in 2011 and 1600 birds in 2012. In total, 24 species ofwaterbirds were affected, including mainly waterfowl (37.0%), shorebirds (27.0%), rallids (25.7%), and larids (9.1%). Mallards (Anas platyrhynchos) and coots (Fulica atra) were most commonly represented among all affected species (27.5% and 25.0% of all recorded carcasses, respectively). Laboratory analyses confirmed the presence of type C botulinum toxin in the internal organs of paralyzed birds. This case study from the Jeziorsko dam reservoir demonstrates that this type of shallow-water habitat is especially prone to avian botulism outbreaks in the climatic conditions of Central Europe.