Genomic relatedness and clinical significance of Streptococcus mitis strains isolated from the urogenital tract of sexual partners.

Research into the lower urinary tract (LUT) microbiota has primarily focused on its relationship to LUT symptoms (LUTS), taking snapshots of these communities in individuals with and without LUTS. While certain bacterial taxa have been associated with LUTS, or the lack thereof, the temporal dynamics of this community were largely unknown. Recently, we conducted a longitudinal study and found that vaginal intercourse resulted in a shift in species richness and diversity within the LUT microbiota. This is particularly relevant as frequent vaginal intercourse is a major risk factor for urinary tract infection (UTI) in premenopausal women (Aydin et al. Int Urogynecol J 2015;26:795-804). To further investigate the relationship between vaginal intercourse and LUT microbiota, here we present the results of a 3 week study in which daily urogenital specimens were collected from a female participant and her male sexual partner. Consistent with our previous findings, the LUT microbiota changed after vaginal intercourse, most notably a high abundance of Streptococcus mitis was observed post-coitus. We isolated and sequenced S. mitis from both sexual partners finding that: (i) the S. mitis isolates from the female partner's urogenital tract were genomically similar throughout the duration of the study, and (ii) they were related to one isolate from the male partner's oral cavity collected at the end of the study, suggesting transmission between the two individuals. We hypothesize that blooms in S. mitis after vaginal intercourse may play a role in coitus-related UTI. We found that a S. mitis isolate, in contrast to a Lactobacillus jensenii isolate displaced after vaginal intercourse, cannot inhibit the growth of uropathogenic Escherichia coli. Thus, this bloom in S. mitis may provide a window of opportunity for a uropathogen to colonize the LUT.

A case report of streptococcal toxic shock syndrome caused by Streptococcus mitis in a healthy adult.

BACKGROUND: Streptococcal toxic shock syndrome (STSS) is an acute, multisystem and toxin-mediated disease that usually causes shock and multiple organ failure in the early stages of its clinical course. It is associated with a substantial increase in mortality rate. The disease has been associated with invasive group A Streptococcus and is rarely caused by Streptococcus mitis (S. mitis). In healthy adults, S. mitis is closely related to endocarditis but rarely related to STSS. CASE PRESENTATION: We report a case of STSS caused by S. mitis in a healthy 45-year-old woman. She presented with fever 14 h after surgery and with hypotension 24 h later, and she subsequently suffered from septic shock, low albumin, dysfunction of coagulation, acute kidney dysfunction, respiratory alkalosis and metabolic acidosis, acute respiratory distress syndrome and cellulitis of the incision. The diagnosis was obtained through clinical manifestation and blood culture examination. The patient was treated with aggressive fluid resuscitation, adequate antibiotics for a total of 4 weeks, respiratory support, and surgical debridement and drainage of the incision. She was discharged after her vital signs returned to normal and the incision healed on day 40 after surgery. CONCLUSIONS: The diagnosis of STSS is often delayed or missed, which leads to a high mortality rate. It is possible to cure patients if the disease can be identified early and treated with aggressive fluid resuscitation, adequate antibiotics and control of the source of infection. Clinicians should consider the disease in the differential diagnosis of septic shock to prevent death.

Identification of Streptococcus pneumoniae and other Mitis streptococci: importance of molecular methods.

The Mitis group of streptococci includes an important human pathogen, Streptococcus pneumoniae (pneumococcus) and about 20 other related species with much lower pathogenicity. In clinical practice, some representatives of these species, especially Streptococcus pseudopneumoniae and Streptococcus mitis, are sometimes mistaken for S. pneumoniae based on the results of classical microbiological methods, such as optochin susceptibility and bile solubility. Several various molecular approaches that address the issue of correct identification of pneumococci and other Mitis streptococci have been proposed and are discussed in this review, including PCR- and gene sequencing-based tests as well as new developments in the genomic field that represents an important advance in our understanding of relationships within the Mitis group.

An oral health optimized diet reduces the load of potential cariogenic and periodontal bacterial species in the supragingival oral plaque: A randomized controlled pilot study.

This study aimed to investigate the effects of an oral health optimized diet on the composition of the supragingival oral plaque in a randomized controlled trial. Participants of the standard diet group (n = 5) had a diet high in processed carbohydrates and did not change their dietary behavior during the observation. The healthy diet group (n = 9) had to change the diet after 2 weeks from a diet high in processed carbohydrates to a diet low in carbohydrates, rich in omega-3 fatty acids, rich in vitamins C and D, antioxidants and fiber for 4 weeks. Saliva and supragingival plaque samples were taken at the end of week two and eight of the observation period to investigate the composition of microbiota in saliva and supragingival plaque. Data were subjected to an exploratory analysis to identify significant differences. Statistically significant differences were only found in the healthy diet group between the baseline (week 2) and the final sample (week 8) for specific species in plaque and saliva samples. A reduction of the total counts of Streptococcus mitis group, Granulicatella adiacens, Actinomyces spp., and Fusobacterium spp. was found in plaque samples of the healthy diet group. In saliva samples of the healthy diet group, the total counts of Actinomyces spp. and Capnocytophaga spp. decreased. A diet low in carbohydrates, rich in omega-3 fatty acids, rich in vitamins C and D, and rich in fiber reduced Streptococcus mitis group, Granulicatella adiacens, Actinomyces spp., and Fusobacterium spp. in the supragingival plaque.

Relationships among streptococci from the mitis group, misidentified as Streptococcus pneumoniae.

The aim of our study was to investigate phenotypic and genotypic features of streptococci misidentified (misID) as Streptococcus pneumoniae, obtained over 20 years from hospital patients in Poland. Sixty-three isolates demonstrating microbiological features typical for pneumococci (optochin susceptibility and/or bile solubility) were investigated by phenotypic tests, lytA and 16S rRNA gene polymorphism and whole-genome sequencing (WGS). All isolates had a 6-bp deletion in the lytA 3' terminus, characteristic for Mitis streptococc and all but two isolates lacked the pneumococcal signature cytosine at nucleotide position 203 in the 16S rRNA genes. The counterparts of psaA and ply were present in 100% and 81.0% of isolates, respectively; the spn9802 and spn9828 loci were characteristic for 49.2% and 38.1% of isolates, respectively. Phylogenetic trees and networks, based on the multilocus sequence analysis (MLSA) scheme, ribosomal multilocus sequence typing (rMLST) scheme and core-genome analysis, clearly separated investigated isolates from S. pneumoniae and demonstrated the polyclonal character of misID streptococci, associated with the Streptococcus pseudopneumoniae and Streptococcus mitis groups. While the S. pseudopneumoniae clade was relatively well defined in all three analyses, only the core-genome analysis revealed the presence of another cluster comprising a fraction of misID streptococci and a strain proposed elsewhere as a representative of a novel species in the Mitis group. Our findings point to complex phylogenetic and taxonomic relationships among S. mitis-like bacteria and support the notion that this group may in fact consist of several distinct species.

Rapid and Accurate Species Identification of Mitis Group Streptococci Using the MinION Nanopore Sequencer.

Differentiation between mitis group streptococci (MGS) bacteria in routine laboratory tests has become important for obtaining accurate epidemiological information on the characteristics of MGS and understanding their clinical significance. The most reliable method of MGS species identification is multilocus sequence analysis (MLSA) with seven house-keeping genes; however, because this method is time-consuming, it is deemed unsuitable for use in most clinical laboratories. In this study, we established a scheme for identifying 12 species of MGS (S. pneumoniae, S. pseudopneumoniae, S. mitis, S. oralis, S. peroris, S. infantis, S. australis, S. parasanguinis, S. sinensis, S. sanguinis, S. gordonii, and S. cristatus) using the MinION nanopore sequencer (Oxford Nanopore Technologies, Oxford, UK) with the taxonomic aligner "What's in My Pot?" (WIMP; Oxford Nanopore's cloud-based analysis platform) and Kraken2 pipeline with the custom database adjusted for MGS species identification. The identities of the species in reference genomes (n = 514), clinical isolates (n = 31), and reference strains (n = 4) were confirmed via MLSA. The nanopore simulation reads were generated from reference genomes, and the optimal cut-off values for MGS species identification were determined. For 31 clinical isolates (S. pneumoniae = 8, S. mitis = 17 and S. oralis = 6) and 4 reference strains (S. pneumoniae = 1, S. mitis = 1, S. oralis = 1, and S. pseudopneumoniae = 1), a sequence library was constructed via a Rapid Barcoding Sequencing Kit for multiplex and real-time MinION sequencing. The optimal cut-off values for the identification of MGS species for analysis by WIMP and Kraken2 pipeline were determined. The workflow using Kraken2 pipeline with a custom database identified all 12 species of MGS, and WIMP identified 8 MGS bacteria except S. infantis, S. australis, S. peroris, and S. sinensis. The results obtained by MinION with WIMP and Kraken2 pipeline were consistent with the MGS species identified by MLSA analysis. The practical advantage of whole genome analysis using the MinION nanopore sequencer is that it can aid in MGS surveillance. We concluded that MinION sequencing with the taxonomic aligner enables accurate MGS species identification and could contribute to further epidemiological surveys.

Delayed diagnosis of right-sided valve endocarditis causing recurrent pulmonary abscesses: a case report.

BACKGROUND: Pulmonary valve infective endocarditis is a rare diagnosis that is usually associated with immunocompromised states or structurally abnormal hearts. It is unusual for it to occur in structurally normal hearts or to cause recurrent symptoms after targeted antibiotics. Although guidelines suggest follow-up with repeat echocardiography and inflammatory marker surveillance, this case demonstrates that these are not always useful investigations, and instead imaging of the chest may be more appropriate. CASE PRESENTATION: We describe a case of a 74-year-old man who presented with respiratory symptoms and was originally misdiagnosed with pneumonia but later found to have a large pulmonary valve vegetation caused by Streptococcus mitis. Despite initially responding to antibiotic therapy, the vegetation continued to cause pulmonary emboli and cavitating lung abscesses months later, necessitating pulmonary valve replacement. CONCLUSIONS: This case demonstrates that pulmonary valve endocarditis can present atypically with recurrent respiratory symptoms, and in such cases, echocardiography should be considered to investigate for right-sided infective endocarditis. In addition, despite correct treatment, with normalization of inflammatory markers and improvement in vegetation size, infective endocarditis can continue to cause systemic symptoms. Finally, clinicians should consider chest computed tomography routinely as part of right-sided infective endocarditis follow-up.

Osteomyelitis of the mandible secondary to malignant infantile osteopetrosis in an adult.

Malignant infantile osteopetrosis (MIOP), an autosomal-recessive disorder, is extremely rare, presenting early in life with extreme sclerosis of the skeleton and reduced activity of osteoclasts. It was first described by Albers Schonberg in 1904. Disease manifestations include compensatory extramedullary haematopoiesis at sites such as the liver and spleen, hepatosplenomegaly, anaemia and thrombocytopaenia. Neurological manifestations can also occur due to narrowing of osseous foramina resulting in visual impairment, hearing loss, facial palsy and hydrocephalus. In addition, growth retardation and recurrent infections requiring long-term antibiotic use are common. The incidence of MIOP is 1/2 000 000 and if untreated, then it has a fatal outcome, with the majority of cases occurring within the first 5 years of life. At present, the only potentially curative option is a haematopoietic stem cell transplant. We present a 21-year-old woman, diagnosed with malignant infantile osteopetrosis, due to a mutation in the T-cell immune regulator 1 gene when aged 6 weeks, presenting with chronic osteomyelitis of her left mandible. As malignant infantile osteopetrosis has a high mortality in infancy, we felt it prudent to report this rare case in a patient surviving to adulthood.

Isolated Pulmonic Valve Endocarditis.

BACKGROUND Infective endocarditis (IE) has a high mortality rate, even when treated with appropriate antibiotic therapy and surgical intervention. Right-sided endocarditis is in itself rare, with some studies reporting an incidence of 5-10%. The majority of these cases involve the tricuspid valve, and isolated pulmonary valve endocarditis (PVE) is an extremely rare entity affecting less than 2% of patients with infective endocarditis. Identification and early management are crucial to prevent long-term complications and reduce mortality. CASE REPORT We present a patient with a history of essential hypertension and no underlying valvular disease, who underwent dental cleaning and subsequently developed low-grade fever, myalgia, and malaise. This occurred during the flu season, and was initially diagnosed and treated as flu, without any improvement. The patient was later found to be bacteremic with S. mitis, with no identifiable source, and a normal transthoracic echocardiogram (TTE). He was later hospitalized, had a transesophageal echocardiogram, and was found to have a large pulmonic valve vegetation. CONCLUSIONS This case presents an interesting and rare finding of endocarditis, isolated to the pulmonic valve, in an otherwise healthy individual with no predisposing risk factors. The lack of peripheral stigmata, as well as an unremarkable initial outpatient TTE, made the diagnosis more difficult. It should also be noted that current guidelines do not specifically address right-sided endocarditis, and do not specify the role of surgical intervention.

Tumefacción en región malar en un neonato / Swelling in the malar region in a neonate

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Mutations in cdsA and pgsA Correlate with Daptomycin Resistance in Streptococcus mitis and S. oralis.

We investigated the ability of several recent clinical viridans group streptococci (VGS) bloodstream isolates (Streptococcus mitis/S. oralis subgroup) from daptomycin (DAP)-naive patients to develop DAP resistance in vitro All strains rapidly developed high-level and stable DAP resistance. Substitutions in two enzymes involved in the cardiolipin biosynthesis pathway were identified, i.e., CdsA (phosphatidate cytidylyltransferase) and PgsA (CDP-diacylglycerol-glycerol-3-phosphate-3-phosphatidyltransferase). These mutations were associated with complete disappearance of phosphatidylglycerol and cardiolipin from cell membranes. DAP interactions with the cell membrane differed in isolates with PgsA versus CdsA substitutions.

A Descriptive Study of Chlorhexidine as a Disinfectant in Cleft Palate Surgery.

OBJECTIVES: Chlorhexidine is seen as the golden standard of disinfectants. It is widely used to clean surgical sites; however, many studies indicate resistance of pathogens to chlorhexidine. One study indicated that pathogenic microorganisms were isolated from the soft palate cleft region in 57% of patients with facial clefts. The objectives of our study were to determine (1) if chlorhexidine application is effective in removing pathogens from the surgical site in these patients, and (2) if any pathogens are isolated, determine if they are resistant to other antimicrobials. DESIGN: A descriptive observational study. SETTINGS: A private practice that specializes in facial cleft surgery, with a country-wide patient base. All procedures were executed by one oral and maxillofacial surgeon. PARTICIPANTS: All patients (N=50) who presented for primary repair of the soft palate cleft were included in the study. INCLUSION CRITERIA: written consent from parent(s), and patient cleared as systemically healthy by a pediatric physician. EXCLUSION CRITERIA: patient(s) with systemic infections (eg, flu) and/or any local infections (eg, tonsillitis). There were 25 males and 25 females with an average age of 7 months and 16 days included in the study. METHODS: Swabs were taken from the surgical site of all 50 patients with cleft soft palate and were sent for culture, identification and antimicrobial sensitivity. The swabs were taken before disinfecting the site as well as after 2 minutes of disinfecting the surgical site with chlorhexidine. Results were compared against each other. RESULTS: Positive cultures with 28 different pathogenic microorganisms that were identified in 47 patients before cleaning the surgical site with the chlorhexidine. The most dominant pathogens were K. pneumonia (n=22), H. influenza (n=18) and S. aureus (n=10). Of the pathogens found, 13 (46%) were still present on the swabs taken after disinfecting with chlorhexidine. K. pneumonia (n= 13), H. influenza (n=11) and S. aureus (n=9) were still the most prevalent pathogens. CONCLUSIONS: This study demonstrated that 61 of the total of 113 pathogens isolated (54%), survived after 2 minutes of disinfecting the surgical and surrounding area with chlorhexidine, thus intensifying the chances of post-operative infection.

A Case Report of Penicillin-Tolerant Streptococcus mitis Endocarditis Chang-Hua Chen, MD, MSc, PhD.

There is no clear relationship between the serum inhibition test and clinical outcome for Streptococcus mitis (S. mitis) endocarditis. We report an 84-year-old male with endocarditis caused by penicillin-tolerant S. mitis. The results for the serum inhibitory test (SIT) and serum bactericidal test (SBT) showed a trough level of SIT = 1:256 and SBT = 1:4 and a peak level of SIT ≥ 1:1024 and SBT = 1:16. In addition, the SIT/SBT ratio was 64 at peak level and more than 64 at trough level, which is compatible with penicillin-tolerant S. mitis. Following a 42-day high-dose penicillin treatment (24 M IU/day, via a continuous drip), the patient made a good recovery. In vitro inhibitory and bactericidal test results were not a valid predictor of medical treatment failure. Physicians need to continue to evaluate the surgical indications when treating patients with S. mitis endocarditis.

Case Report: Iatrogenic Infection from Traditional Treatment of Stingray Envenomation.

A 47-year-old man was stung on the left ankle by a stingray while on vacation on the Island of Bubaque, Guinea-Bissau. The affected limb was initially treated with an attempt to suck out the venom and application of chewed plant root. The following 3 days, local pain gradually diminished, but then high fever erupted together with generalized symptoms and intense pain from the ankle. After initiating antibiotic treatment, the patient was evacuated. Because of sustained symptoms and fever, the wound was surgically debrided, and culture revealed infection with oral flora bacteria. Attempts to suck out venom are not recommended.