Streptococcus pluranimalium: Emerging Animal Streptococcal Species as Causative Agent of Human Brain Abscess

Antimicrobial susceptibility rates in gram-positive catalase-negative cocci from sheep and goat genital microbiota

Gram-positive catalase-negative cocci (GPCNCs) are significant components of the genital microbiota in sheep and goats. However, characterizing them can be difficult due to overlapping culture features and the limited information on their susceptibility to antibiotics. In this study, 97 foreskin and 13 vaginal swabs were investigated using a culturomic approach. Of 110 animals, 76 (69.09 %) hosted GPCNCs, including strains from Streptococcaceae (37, 33.64 %), Aerococcaceae (30, 27.27 %), Enterococcaceae (6, 5.45 %) and other minor species. With increasing antimicrobial resistance rates in livestock, surveillance programs are globally required, so we conducted a pilot study on GPCNCs isolated from the genital mucosa surfaces of sheep and goats using the minimal inhibitory concentration assay (MIC). Due to gaps in interpretative standard breakpoints, normalized resistance interpretation was used for setting epidemiological susceptibility cut-off values (COWTs). Of 57 suitable strains, the majority (80.71 %) showed high COWTs with decrease susceptibility to at least one antimicrobial class, with 22.81 % displaying multiresistant profiles. Of interest, combined resistances to beta-lactams, macrolides, lincosamides, and tetracyclines were detected in strains of Streptococcus plurianimalium. Further combinations, including resistance to beta-lactams, pleuromutilins, aminoglycosides, and lincosamides, were also recorded in both Streptococcus uberis and Enterococcus spp. strains. Being beta-lactams, macrolides, and tetracyclines the most used antibiotics in livestock worldwide, our results highlight the need for their prudent use. Collectively, our findings highlight that small ruminant genital microbiota can serve as reservoirs for opportunistic severe pathogens, often zoonotic, carrying multidrug resistances, thus standing for high risks for both animals and humans.

The pseudokinase MLKL contributes to host defense against Streptococcus pluranimalium infection by mediating NLRP3 inflammasome activation and extracellular trap formation

Host innate immunity plays a pivotal role in the early detection and neutralization of invading pathogens. Here, we show that pseudokinase mixed lineage kinase-like protein (MLKL) is required for host defence against Streptococcus pluranimalium infection by enhancing NLRP3 inflammasome activation and extracellular trap formation. Notably, Mlkl deficiency leads to increased mortality, increased bacterial colonization, severe destruction of organ architecture, and elevated inflammatory cell infiltration in murine models of S. pluranimalium pulmonary and systemic infection. In vivo and in vitro data provided evidence that potassium efflux-dependent NLRP3 inflammasome signalling downstream of active MLKL confers host protection against S. pluranimalium infection and initiates bacterial killing and clearance. Moreover, Mlkl deficiency results in defects in extracellular trap-mediated bactericidal activity. In summary, this study revealed that MLKL mediates the host defence response to S. pluranimalium, and suggests that MLKL is a potential drug target for preventing and controlling pathogen infection.

Biological Properties of Streptococcus pluranimalium as the New Human Pathogen

BACKGROUND: The limited amount of information available today does not fully reflect the biological properties of Streptococcus pluranimalium as a pathogen new to humans, its pathogenicity factors, and, as a consequence, the pathogenesis of diseases, which is causes AIM: The aim of this research was to study the biological properties of S. pluranimalium, its sensitivity to antibiotics and antiseptics, as well as its adhesive properties. METHODS: Two hundred samples were collected from the coronal pockets in patients with acute purulent pericoronitis during 2019–2021 years. Among them, five clinical strains of S. pluranimalium were isolated. Final identification was carried out using a Vitec-2compact bioMérieux automatic bacteriological analyzer. The sensitivity of the studied microbial strains to antibiotics of various groups was determined by the disk diffusion method. The adhesive properties of S. pluranimalium were determined according to the standard Brilis method. RESULTS: It possesses typical morphological and cultural properties characteristics of the genus Streptococcus representatives. This microorganism virtually does not break down carbohydrates, but it produces arylamidases that enables it to be differentiated from other streptococci. S. pluranimalium demonstrates variable sensitivity to antibiotics; the lowest sensitivity has been found out to the second-generation fluoroquinolones. In addition, the clinical isolates studied show high adhesive properties to human red blood cells. CONCLUSIONS: S. pluranimalium is increasingly acting as the causative agent of human infectious diseases. The information available today fully reflects the biological properties of a pathogen new to humans, its pathogenicity factors.

Post-traumatic endophthalmitis caused by streptococcus species in preschool children: clinical features, antibiotic susceptibilities and outcomes

BACKGROUND/OBJECTIVES

Streptococcus is a common cause of post-traumatic endophthalmitis in children. This study aimed to analyse the clinical features, antibiotic susceptibilities and outcomes of traumatic endophthalmitis caused by streptococcus in preschool children.

SUBJECTS/METHODS

Patients aged ≤6 years with traumatic streptococcal endophthalmitis seen at Zhongshan Ophthalmic Center between January 2013 and December 2018 were included in this retrospective study.

RESULTS

In total, 21 patients (21 eyes) were included. The mean age of the patients was 3.3 ± 1.7 years, where 57.1% were males. Scissors (28.6%, n = 6) were the most common cause of injury; 86.7% of patients were injured at home. Zone I (80.9%) was the most common wound site; 90.5% of patients presented with a traumatic cataract. In general, Streptococcus pneumoniae (47.6%) was the most common isolate. Viridans group streptococci accounted for 58.3% of cases in children aged 0-3 years, while S. pneumoniae accounted for 66.7% of cases in children aged 4-6 years. The susceptibility rates of streptococcus to cefuroxime, levofloxacin and ofloxacin were 100%, 95.0% and 90.5%, respectively. Although all the patients underwent vitrectomy combined with silicone oil tamponade, the final visual outcomes were no better than counting fingers.

CONCLUSIONS

Although S. pneumoniae was the most prevalent organism in general, the dominant species varied between different age groups. The commonly used antibiotics, cefuroxime and fluoroquinolone, showed higher antibiotic susceptibility. Despite prompt treatment, the visual outcomes of paediatric post-traumatic endophthalmitis in preschool children were poor.

Streptococcus pluranimalium meningoencephalitis in a horse

A 3-y-old, female Quarter Horse with a history of acute neurologic signs was found dead and was submitted for postmortem examination. Areas of petechial and ecchymotic hemorrhage were present on cross-sections of the cerebrum, cerebellum, and brainstem. Histologic examination of the brain revealed severe, purulent meningoencephalitis and vasculitis with a myriad of intralesional gram-positive cocci. Streptococcus pluranimalium was identified from formalin-fixed, paraffin-embedded tissue obtained from sites with active lesions by PCR and nucleotide sequencing of bacterial 16S ribosomal RNA. S. pluranimalium should be considered as a cause of meningoencephalitis in a horse.

Brain abscess burr hole aspiration in children with congenital heart disease in low facility centers: case series

This is a prospective cross-sectional study on brain abscess burr hole aspiration in children with congenital heart disease (CHD) performed from January 2018 to March 2019. All patients were operated on through a burr hole, and then received intravenous antibiotics for 6 weeks and orally for 2 weeks either empirically or according to the results of abscess culture, if positive. The follow-up of cranial computed tomography or brain magnetic resonance image with contrast was obtained after 2 months (post-operatively) to assess the effectiveness of the procedure and to look for any residual or recurrent abscesses. Data were collected in a designed data collection sheet and analysed using Statistical Package for the Social Sciences-20. Thirteen patients were found to satisfy inclusion criteria. The most common presenting symptoms were fever (n = 11/13, 84.6%), vomiting (n = 7/13, 53.8%), headache (n = 6/13, 46.2%), convulsions (n = 6/13, 46.2%), focal weakness (n = 3/13, 23.1%), and impaired level of consciousness (n = 1/13, 7.7%). No bacterial growth was detected in two-thirds of the cases (69.2%), while the culture was positive in the remaining one-third (30.8%). The follow-up images showed complete resolution of the abscesses except in one case (n = 1/13, 7.7%), which required a second session of aspiration. One patient died (n = 1/13, 7.7%) on the 19th post-operative day due to severe pneumonia. Aspiration of brain abscess in children with CHD through a burr hole is a safe and effective procedure in terms of operative time, duration of anaesthesia and postoperative complications.

Microbial Communities of Meat and Meat Products: An Exploratory Analysis of the Product Quality and Safety at Selected Enterprises in South Africa

Consumption of food that is contaminated by microorganisms, chemicals, and toxins may lead to significant morbidity and mortality, which has negative socioeconomic and public health implications. Monitoring and surveillance of microbial diversity along the food value chain is a key component for hazard identification and evaluation of potential pathogen risks from farm to the consumer. The aim of this study was to determine the microbial diversity in meat and meat products from different enterprises and meat types in South Africa. Samples (n = 2017) were analyzed for Yersinia enterocolitica, Salmonella species, Listeria monocytogenes, Campylobacter jejuni, Campylobacter coli, Staphylococcus aureus, Clostridium perfringens, Bacillus cereus, and Clostridium botulinum using culture-based methods. PCR was used for confirmation of selected pathogens. Of the 2017 samples analyzed, microbial ecology was assessed for selected subsamples where next generation sequencing had been conducted, followed by the application of computational methods to reconstruct individual genomes from the respective sample (metagenomics). With the exception of Clostridium botulinum, selective culture-dependent methods revealed that samples were contaminated with at least one of the tested foodborne pathogens. The data from metagenomics analysis revealed the presence of diverse bacteria, viruses, and fungi. The analyses provide evidence of diverse and highly variable microbial communities in products of animal origin, which is important for food safety, food labeling, biosecurity, and shelf life limiting spoilage by microorganisms.

The first report of Streptococcus pluranimalium infection from Iran: A case report and literature review

The Streptococcus pluranimalium was isolated from both of animals and human infection. There is limited information about pathogenicity of S pluranimalium. As fastidious bacteria, S pluranimalium is not isolated in the routinely culture media and easily misidentified with other streptococci species with conventional microbiology test. According to review of the literatures, the cephalosporins, aminoglycosides, vancomycin, and linezolid are the first choice agents for treatment of infection caused by S pluranimalium.

Streptococcus pluranimalium infective endocarditis and brain abscess

Infective endocarditis is an infection of the endocardium of the heart typically seen in individuals with underlying risk factors. We report a rare case of Streptococcus pluranimalium bacteremia causing infective endocarditis and brain abscess. Only 3 cases were reported in the literature on infective endocarditis in patients secondary to S. pluranimalium.

Characterization of Streptococcus pluranimalium from a cattle with mastitis by whole genome sequencing and functional validation

Background

Streptococcus pluranimalium is a new member of the Streptococcus genus isolated from multiple different animal hosts. It has been identified as a pathogen associated with subclinical mastitis, valvular endocarditis and septicaemia in animals. Moreover, this bacterium has emerged as a new pathogen for human infective endocarditis and brain abscess. However, the patho-biological properties of S. pluranimalium remain virtually unknown. The aim of this study was to determine the complete genome sequence of S. pluranimalium strain TH11417 isolated from a cattle with mastitis, and to characterize its antimicrobial resistance, virulence, and carbon catabolism.

Results

The genome of S. pluranimalium TH11417, determined by single-molecule real-time (SMRT) sequencing, consists of 2,065,522 base pair (bp) with a G + C content of 38.65%, 2,007 predicted coding sequence (CDS), 58 transfer RNA (tRNA) genes and five ribosome RNA (rRNA) operons. It contains a novel ISSpl1 element (a memeber of the IS3 family) and a Ф11417.1 prophage that carries the mef(A), msr(D) and lnu(C) genes. Consistently, our antimicrobial susceptibility test confirmed that S. pluranimalium TH11417 was resistant to erythromycin and lincomycin. However, this strain did not show virulence in murine pneumonia (intranasal inoculation, 10⁷ colony forming unit – CFU) and sepsis (intraperitoneal inoculation, 10⁷ CFU) models. Additionally, this strain is able to grow with glucose, lactose or galactose as the sole carbon source, and possesses a lactose-specific phosphoenolpyruvate-dependent phosphotransferase system (PTS).

Conclusions

We reported the first whole genome sequence of S. pluranimalium isolated from a cattle with mastitis. It harbors a prophage carrying the mef(A), msr(D) and lnu(C) genes, and is avirulent in the murine infection model.