Exploring Yak (Bos grunniens) Rumen Bacterial and Fungal Communities from 5 Days after Birth to Adulthood

The gut microbial community of mammals, especially ruminants, plays an important role at different ages of the host. Ruminants have a unique compartment in their digestive tract; the rumen, comprising microorganisms that can effectively decompose plant fibers for the host to transform into milk and for growth and development, which is important for meat production. Colonization of rumen microorganisms is closely related to host developmental stage and affects host performance production. There is little information regarding initial colonization and subsequent changes of the rumen microbial population in wild grazing animals, from birth to adulthood. This study investigated the rumen bacterial and fungal populations of grazing yaks in five experimental groups, ranging from a few days after birth to adulthood using amplicon sequencing. Results indicated that rumen microbial communities of these yaks undergo a gradual change from 5 to 180 days after birth, with the bacterial and fungal diversity stabilizing at the age of 2 years. Additionally, Ruminococcus was detected in 5-day-old yak rumens, with a high percentage of Penicillium and other microbial species are important for normal rumen function detected in the adult rumen. The changes to the yak rumen microbial community after birth were reflected in the increased anaerobic fiber degradation group, and decreased aerobic and facultative anaerobic bacteria. Microbial diversity and abundance in the yak rumen increased with age. Rumen microbial composition of 6-month and 2-year-old yaks had obvious homogeneity. There were some differences in dominant rumen microorganisms among the different age groups. Further studies are required to confirm the functions of these differential and dominant microorganisms in each age group.

Actinomycosis in head and neck region of pediatric patients: a review

The majority of cases of actinomycosis are of odontogenic origin and related to the perimandibular region with other sites of primary actinomycosis in the head and neck region include the tongue, paranasal sinuses, middle ear, larynx, lacrimal passage, and thyroid gland. Actinomycosis is an uncommon infection caused by Actinomyces species, facultative anaerobic bacteria that are part of the normal flora in the oropharynx, gastrointestinal tract, and female genital tract. The risk factors for actinomycosis in the pediatric age group are dental caries, trauma, debilitation, and poorly controlled diabetes mellitus. The pathogenesis of the actinomycosis in the head and neck region is often unclear. The hallmark of actinomycosis is the spread of infection which fails to respect the tissue or fascial planes. The organism causing actinomycosis is often difficult to isolate from culture and the differential diagnosis is extensive which prompts clinicians to name the actinomycosis the masquerader of the head and neck area. This clinical entity in pediatric patients may mimic malignancy or granulomatous disease in the head and neck region. Clinicians must be aware of typical presentations of actinomycosis in the head and neck region. Bacterial cultures and histopathological study are the cornerstones of the diagnosis of actinomycosis, however, particular conditions are needed to find the exact diagnosis. The treatment of actinomycosis includes a combination of surgery and antibiotic therapy. Surgery is an important adjunctive to medical therapy in patients with extensive lesions of actinomycosis. Actinomyces species are uniformly susceptible to penicillin. This review article discusses the etiopathology, epidemiology, clinical manifestations, diagnosis, and current treatment of the actinomycosis in the head and neck region of pediatric patients.

Optimized Attenuated Salmonella Typhimurium Suppressed Tumor Growth and Improved Survival in Mice

The gram-negative facultative anaerobic bacteria Salmonella enterica serovar Typhimurium (hereafter S. Typhimurium) has always been considered as one candidate of anti-tumor agents or vectors for delivering drug molecules. In this study, we compared several widely studied S. Typhimurium strains in their anti-tumor properties aiming to screen out the best one for further optimization and use in cancer therapy. In terms of the motility, virulence and anti-tumor efficacy, the three strains 14028, SL1344, and UK-1 were similar and obviously better than LT-2, and UK-1 showed the best phenotypes among them. Therefore, the strain UK-1 (D) was selected for the following studies. Its auxotrophic mutant strain (D1) harboring ∆aroA and ∆purM mutations was further optimized through the modification of lipid A structure, generating a new strain named D2 with stronger immunostimulatory activity. Finally, the ∆asd derivative of D2 was utilized as one live vector to deliver anti-tumor molecules including the angiogenesis inhibitor endostatin and apoptosis inducer TRAIL and the therapeutic and toxic-side effects were evaluated in mouse models of colon carcinoma and melanoma. After intraperitoneal infection, engineered Salmonella bacteria equipped with endostatin and/or TRAIL significantly suppressed the tumor growth and prolonged survival of tumor-bearing mice compared to PBS or bacteria carrying the empty plasmid. Consistently, immunohistochemical studies confirmed the colonization of Salmonella bacteria and the expression of anti-tumor molecules inside tumor tissue, which were accompanied by the increase of cell apoptosis and suppression of tumor angiogenesis. These results demonstrated that the beneficial anti-tumor efficacy of attenuated S. Typhimurium bacteria could be improved through delivery of drug molecules with powerful anti-tumor activities.

Species Composition and Susceptibility to Antibiotics of Microorganisms Isolated from Tooth Sockets of Extracted Teeth in Cases of Alveolar Osteitis

Alveolar osteitis (AO) is one of the most common infectious complications after dental extractions. The data on the species composition of AO pathogens and their susceptibility to antimicrobial drugs can be the basis for their empirical use in case of inflammatory process aggravation. Objective. To determine the species composition and susceptibility to the antimicrobial agents of microorganisms, which were detected in patients with AO, who sought medical help in the oral surgery department of the dental medical center of Bogomolets National Medical University. Methods. Throughout 2018–2021, microbiological examination of tooth sockets from 30 patients with AO and 20 patients without AO was performed. The studied biological material was plated on appropriate nutrient media for isolation of aerobic, facultative and obligate-anaerobic microorganisms. Anaerobic conditions were achieved in GENbox 7.0 L and GENbox 2.5 L aerostats using GENbox anaerobic packages (“Biomerieux”, France). The genus and species identity of the bacteria were determined according to Bergey. Antibiotic susceptibility of the isolated strains was determined by disk diffusion method. Results. It was found that most commonly microorganisms from tooth sockets in case of AO are: Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus spp., Escherichia coli, Bacteroides spp., Clostridium spp., and Candida species, as well as their mixed cultures of 3–5 species of microorganisms. These aerobic and facultative anaerobic bacteria were susceptible to amoxicillin, ceftriaxone and ciprofloxacin in 92.6–100% of cases. The growth of anaerobic bacteria in 100% of cases was inhibited by colistin and meropenem. Conclusions. AO developing is caused by pathological colonization of socket of the extracted tooth by representatives of endogenous microbiota, namely Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus spp., Escherichia coli, which are present mainly in the mixed cultures with Candida albicans. For empirical antibiotic therapy of complicated forms of AO, amoxicillin or ceftriaxone or ciprofloxacin in complex with colistin or meropenem should be used, since these drugs suppress the growth of 92.6–100% of strains of aerobic, facultative and obligate anaerobic microorganisms, which are potential pathogens of the purulent forms of AO.

A New PNA-FISH Probe Targeting Fannyhessea vaginae

Bacterial vaginosis (BV) is the most common vaginal infection in women of reproductive age and has been associated with serious health complications, mainly in pregnant women. It is characterized by a decrease in the number of Lactobacillus species in the healthy vaginal microbiota and an overgrowth of strict and facultative anaerobic bacteria that develop a polymicrobial biofilm. Despite over 60 years of research investigating BV, its etiology is not fully understood. Gardnerella spp. is a crucial microorganism that contributes to the formation of the biofilm and the development of BV, but the role of other BV-associated bacteria is not clear. Nevertheless, Fannyhessea vaginae (previously known as Atopobium vaginae) is a highly specific species for BV, and co-colonization with Gardnerella is thought to be a very specific diagnostic marker. The diagnosis of BV still presents some limitations, since currently used methods often fail to accurately detect BV. This work aims to develop a novel peptide nucleic acid (PNA) probe targeting F. vaginae. This probe was further validated in a multiplex assay, which included a Gardnerella-specific PNA probe, as a possible method for diagnosis of BV, and was compared with quantification by qPCR. The new PNA probe showed excellent sensitivity and specificity and could discriminate F. vaginae-Gardnerella biofilms, confirming the potential to be used for the detection of BV-associated pathogens.

ANTIBACTERIAL EFFECTIVENESS OF LERAK FRUIT ETHANOL EXTRACT (Sapindus rarak DC) AND 2% CHLORHEXIDINE IN Enterococcus faecalis

The failure of a root canal treatment can be caused by the facultative anaerobic bacteria Enterococcus faecalis, which should be eliminated throughout root canal irrigation. Chlorhexidine 2% is a popular antibacterial liquid used in root canal irrigation. Natural substances can also be used to make antibacterial irrigation liquids. One natural substance with antibacterial properties is lerak fruit extract (Sapindus rarak DC), containing 28 per cent of saponins, alkaloid compounds, polyphenols, antioxidant chemicals, and flavonoid groups and tannins. This study was conducted to determine the effectiveness of 25% lerak fruit extract (Sapindus rarak DC) against E. faecalis compared to 2% Chlorhexidine. This study is a pure experimental study using the agar diffusion method against three experimental groups chlorhexidine 2% as a positive control, lerak fruit extract (Sapindus rarak DC) as a treatment group, and aquadest as a negative control. Each group was repeated ten times on Muller Hinton Agar (MHA) media which was applied using a paper disc. Then the diameter of the inhibition zone was calculated using a caliper. The results in this study, 25% lerak (Sapindus rarak DC) fruit extract had an average inhibition zone diameter of 11.775 mm, and an average inhibition zone diameter of 2% chlorhexidine was 19.745 mm. The difference in the diameter of the inhibition zone was significantly different in all groups. Conclusion ethanol extract of lerak fruit (Sapindus rarak DC) 25% can inhibit the growth of E. faecalis and can be used as an alternative to other antimicrobial agents as disinfection of root canal irrigation.

Investigation of the Long-Term Antibacterial Properties of Titanium by Two-Step Micro-Arc Oxidation Treatment

Recently, biofilm formation caused by bacterial adhesion and colonization has been recognized as the major cause of failure in orthopedic and dental implant surgeries. In this study, a customized micro-arc oxidation (MAO) treatment technique was developed to obtain desirable antibacterial properties on Ti surfaces. The two-step MAO treatment was applied in the fabrication of specimens with Ag and with/without Zn in their surface oxide layer. In order to simulate practical usage, surface analyses and immersion tests were performed to evaluate the incorporation of Ag and Zn into the resulting oxide layer and ion release behavior, respectively. Additionally, the antibacterial properties of the specimens after long-term immersion in physiological saline were evaluated using Gram-negative facultative anaerobic bacteria. The MAO-treated specimens containing Ag and Zn exhibited excellent antibacterial properties against Escherichia coli, which were sustained even after 6 months of immersion in physiological saline to simulate practical usage. Moreover, the Ag ions released from the surface oxide indicate the antibacterial properties of the specimen in the early stage, while the release of the corrosion products of Zn demonstrates its antibacterial properties in the later stage.

Primary mammary actinomycosis challenged with penicillin allergy

Actinomycosis is a subacute-to-chronic bacterial infection caused by gram-positive, filamentous, non-acid-fast, facultative anaerobic bacteria. It is a normal commensal bacterium found in the oral cavity and the lower reproductive tract of women. We present a case of primary actinomycosis of the breast. A postmenopausal woman, complicated by penicillin allergy, presented with a left breast lump clinically simulating malignancy. The first line of treatment for actinomycosis is penicillin. Due to a penicillin allergy, the patient was initially treated with doxycycline. However, doxycycline was discontinued due to tremors, and was replaced by clindamycin. The patient had a good clinical response with resolution of the abscess.

Unraveling the Etiology of Periodontitis

Across the globe, incidence of oral afflictions like gingivitis and periodontitis are increasing at a very fast pace. Evidencearethere to support the fact that despite of being an oro-dental infection, periodontitis is associated with the systemic diseases too. Different ecological niches of oral cavity can harbor both pathogenic and non-pathogenic micro-organisms. Although the main cause of the disease is the anaerobic or the facultative anaerobic bacteria, other factors such as poor personal hygiene, diet and immune related disorders are also responsible for the progression of the disease. The vicious circle starts from deposition of the bacterial plaque/biofilm on the tooth surface then leading to gingivitis. If left untreated, it progresses to the development of periodontal pockets and ultimately tooth loss. However traditional treatment modalities like high dose of systemic antibiotics are available but antimicrobial resistance and virulence of the periodontal pathogens is the major cause of the treatment failures. This review primarily focuses on the etiology, pathogenesis and microbiology of the periodontitis. It also discusses the virulence and antimicrobial resistance factors of the periodontopathic micro-organisms. It is an attempt to develop the thorough understanding of the disease so that better therapeutic outcomes of periodonto-therapy can be attained.