Molecular and sequencing study and identification of novel SeM-type in beta-hemolytic streptococci involving the upper respiratory tract in Iran.

BACKGROUND: Beta-hemolytic streptococci involving the upper respiratory tract cause strangles and strangles-like diseases in horses and cause severe economic damage to the equestrian club each year. Therefore, careful epidemiological study of these bacteria, evaluation of phylogenetic connections and SeM-typing can be useful to determine the source and epidemiological characteristics of the disease outbreak. Isolates were analyzed using molecular and phylogenetic methods and to determine antibiotic resistance pattern in Iranian isolates. Molecular and phylogenetic methods were used to evaluate Iranian streptococcal isolates, and the similarity of the Iranian SeM-97 sequence with other alleles was assessed using the Neighbor-joining method with the Kimura 2 Parameter statistical model. The amino acid sequence of this gene was compared with the predicted SeM-3 reference amino acid sequence (FM204883) using MEGA 7 software. RESULTS: One type of SeM was found among streptococcal isolates. This type (SeM-97) was reported for the first time and was a new SeM. The relationship between streptococcal isolates and age, sex, race, clinical signs and geographical area was investigated. A significant relationship was observed between streptococcal isolates with age variables and clinical symptoms. CONCLUSIONS: In our study, a Streptococcus equi subsp. equi genotype was identified. The 97 allele of this gene has not been officially reported anywhere and is only registered in the Public databases for molecular typing and microbial genome diversity (PubMLST)-SeM database by Katy Webb. This was the first isolate reported and registered in the mentioned database. The isolate (Tabriz61) had the SeM-97 allele with clinical signs including mucopurulent discharge, abnormal sounds in lung hearing, warmth and enlargement or discharge and abscess of retropharyngeal lymph node and fever. This isolate was sensitive to penicillin, meropenem, ampicillin, cefotaxime, tetracycline, erythromycin, azithromycin, chloramphenicol, enrofloxacin and ciprofloxacin antibiotics and resistant to trimethoprim-sulfamethoxazole and gentamicin antibiotics.

Microbiological Epidemiology of Invasive Infections Due to Non-Beta-Hemolytic Streptococci, France, 2021.

Non-beta-hemolytic streptococci (NBHS), also referred to as viridans streptococci, represent an underestimated cause of human invasive diseases. Their resistance to antibiotics, including beta-lactam agents, often complicate their therapeutic management. A prospective multicenter study was conducted by the French National Reference Center for Streptococci between March and April 2021 to describe the clinical and microbiological epidemiology of invasive infections due to NBHS, excluding pneumococcus. A total of 522 NBHS invasive cases were collected. Distribution among streptococcal groups was: Streptococcus anginosus (33%), Streptococcus mitis (28%), Streptococcus sanguinis (16%), Streptococcus bovis/equinus (15%), Streptococcus salivarius (8%), and Streptococcus mutans (<1%). Median age of infection was 68 years old (range <1 day to 100 years). Cases were more frequent in male patients (gender ratio M/F 2.1:1) and manifested mainly as bacteremia without focus (46%), intra-abdominal infections (18%) and endocarditis (11%). All isolates were susceptible to glycopeptides and displayed low-level inherent gentamicin resistance. All isolates of the S. bovis/equinus, S. anginosus, and S. mutans groups were susceptible to beta-lactams. Conversely, nonsusceptibility to beta-lactams was found in 31%, 28%, and 52% of S. mitis, S. salivarius, and S. sanguinis isolates, respectively. The screening for beta-lactam resistance using the recommended one unit benzylpenicillin disk screening failed to detect 21% of resistant isolates (21/99). Last, overall resistance rates to the alternative anti-streptococcal molecules clindamycin and moxifloxacin were 29% (149/522) and 1.6% (8/505), respectively. IMPORTANCE NBHS are recognized as opportunistic pathogens particularly involved in infections of the elderly and immunocompromised patients. This study underlines their importance as common causes of severe and difficult-to-treat infections such as endocarditis. Although species of the S. anginosus and S. bovis/equinus groups remain constantly susceptible to beta-lams, resistance in oral streptococci exceeds 30% and screening techniques are not fully reliable. Therefore, accurate species identification and antimicrobial susceptibility testing by MICs determination appears essential for the treatment of NBHS invasive infections, together with continued epidemiological surveillance.

Influence of a guideline or an additional rapid strep test on antibiotic prescriptions for sore throat: the cluster randomized controlled trial of HALS (Hals und Antibiotika Leitlinien Strategien).

BACKGROUND: Pharyngitis due to Group A beta-hemolytic streptococci (GAS) is seen as the main indication for antibiotics for sore throat. In primary care settings prescription rates are much higher than the prevalence of GAS. Recommendations in international guidelines differ considerably. A German guideline suggested to consider antibiotics for patients with Centor or McIsaac scores ≥ 3, first choice being penicillin V for 7 days, and recommended analgesics for all. We investigated, if the implementation of this guideline lowers the antibiotic prescription rate, and if a rapid antigen detection strep-test (RADT) in patients with scores ≥ 3 lowers the rate further. METHODS: HALS was an open pragmatic parallel group three-arm cluster-randomized controlled trial. Primary care practices in Northern Germany were randomized into three groups: Guideline (GL-group), modified guideline with a RADT for scores ≥ 3 (GL-RADT-group) or usual care (UC-group). All practices were visited and instructed by the study team (outreach visits) and supplied with material according to their group. The practices were asked to recruit 11 consecutive patients ≥ 2 years with an acute sore throat and being at least moderately impaired. A study throat swab for GAS was taken in every patient. The antibiotic prescription rate at the first consultation was the primary outcome. RESULTS: From October 2010 to March 2012, 68 general practitioners in 61 practices recruited 520 patients, 516 could be analyzed for the primary endpoint. Antibiotic prescription rates did not differ between groups (p = 0.162) and were about three times higher than the GAS rate: GL-group 97/187 patients (52%; GAS = 16%), GL-RADT-group 74/172 (43%; GAS = 16%) and UC-group 68/157 (43%; GAS = 14%). In the GL-RADT-group 55% of patients had scores ≥ 3 compared to 35% in GL-group (p < 0.001). After adjustment, in the GL-RADT-group the OR was 0.23 for getting an antibiotic compared to the GL-group (p = 0.010), even though 35 of 90 patients with a negative Strep-test got an antibiotic in the GL-RADT-group. The prescription rates per practice covered the full range from 0 to 100% in all groups. CONCLUSION: The scores proposed in the implemented guideline seem inappropriate to lower antibiotic prescriptions for sore throat, but better adherence of practitioners to negative RADTs should lead to fewer prescriptions. TRIAL REGISTRATION: DRKS00013018, retrospectively registered 28.11.2017.

Tetracycline, Macrolide and Lincosamide Resistance in Streptococcus canis Strains from Companion Animals and Its Genetic Determinants.

Growing antimicrobial resistance (AMR) in companion-animal pathogens, including Streptococcus canis (S. canis), is a significant concern for pet treatment as well for public health. Despite the importance of S. canis in veterinary and human medicine, studies concerning the AMR of this bacterium are still scarce. A total of 65 S. canis strains, isolated from dogs and cats, were assessed to test for susceptibility to six clinically relevant antimicrobials via a microdilution method. The prevalence of the selected acquired-resistance genes was also investigated via PCR. High MIC50 and MIC90 values (≥128 µg/mL) were noted for tetracycline, erythromycin and clindamycin. Only a few strains were resistant to the tested beta-lactams (6.2%). Tetracycline resistance was found in 66.2% of the strains. Resistance to erythromycin and clindamycin (ML resistance) was found in 55.4% of the strains. Strains with a phenotype showing concurrent resistance to tetracycline and ML were predominant (53.8%). AMR in the tested S. canis strains was associated with a variety of acquired and potentially transferable genes. Tetracycline resistance was conferred by tet(O) (40.0%), tet(M) (9.2%), and tet(T) (1.5%), which is reported for the first time in S. canis. In most cases, the tet(M) gene was detected in relation to the conjugative transposon Tn916. The MLSB phenotype was confirmed in the strains harboring erm(B) (43.1%) and erm(TR) (7.7%). To conclude, a high rate of S. canis strains occurring in dogs and cats displayed resistance to antimicrobials important for treatment; moreover, they are a potential reservoirs of various resistance determinants. Therefore, AMR in these pathogens should be continuously monitored, especially regarding the One Health concept.

Antimicrobial Resistance among Beta-Hemolytic Streptococcus in Brazil: An Overview.

Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus dysgalactiae subsp. equisimilis (SDSE) are the beta-hemolytic streptococci species with the most clinical relevance to humans. These species are responsible for several infections, ranging from mild to life-threatening diseases. Although resistance to recommended drugs has not been so critical as detected in other species, it has occurred in diverse regions. In Brazil, it is possible to observe an increasing macrolide and lincosamide resistance trend due to the spread of polyclonal strains. Macrolide-lincosamide-streptogramin B (MLS) resistance phenotypes have been prevalent among S. agalactiae and S. pyogenes, while M phenotype (resistance only to macrolides) has prevailed among SDSE resistant isolates. Fluoroquinolone resistance is rare in this country, reported only in S.agalactiae and S.pyogenes. This is due to nucleotide substitutions in gyrA and parC genes. Reduced penicillin susceptibility and vancomycin resistance, detected in other regions, have not yet been reported in Brazil. Tetracycline is not a therapeutical option, and resistance has occurred at high levels, especially among S.agalactiae. These findings highlight the need for continuous monitoring in order to track the occurrence of antimicrobial resistance among beta-hemolytic streptococci species circulating in this country.

Streptococcal Infection as a Major Historical Cause of Stuttering: Data, Mechanisms, and Current Importance.

Stuttering is one of the most well-known speech disorders, but the underlying neurological mechanisms are debated. In addition to genetic factors, there are also major non-genetic contributions. It is here proposed that infection with group A beta-hemolytic streptococcus (GAS) was a major underlying cause of stuttering until the mid-1900s when penicillin was introduced in 1943. The main mechanism proposed is an autoimmune reaction from tonsillitis, targeting specific molecules, for example within the basal ganglia. It is here also proposed that GAS infections may have continued to cause stuttering to some extent, to the present date, though more rarely. If so, early diagnosis of such cases would be of importance. Childhood cases with sudden onset of stuttering after throat infection may be particularly important to assess for possible GAS infection. The support for this hypothesis primarily comes from three lines of argument. First, medical record data from the 1930s strongly indicates that there was one type of medical event in particular that preceded the onset of childhood stuttering with unexpected frequency: diseases related to GAS throat infections. In particular, this included tonsillitis and scarlet fever, but also rheumatic fever. Rheumatic fever is a childhood autoimmune sequela of GAS infection, which was a relatively widespread medical problem until the early 1960s. Second, available reports of changes of the childhood prevalence of stuttering indicate striking parallels between stuttering and the incidence of rheumatic fever, with: (1) decline from the early 1900s; (2) marked decline from the introduction of penicillin in the mid 1940s; and (3) reaching a more stable level in the 1960s. The correlations between the data for stuttering and rheumatic fever after the introduction of penicillin are very high, at about 0.95. Third, there are established biological mechanisms linking GAS tonsillitis to immunological effects on the brain. Also, a small number of more recent case reports have provided further support for the hypothesis linking stuttering to GAS infection. Overall, it is proposed that the available data provides strong evidence for the hypothesis that GAS infection was a major cause of stuttering until the mid-1900s, interacting with genetic predisposition.

Beta-Hemolytic Streptococcal Infective Endocarditis: Characteristics and Outcomes From a Large, Multinational Cohort.

BACKGROUND: Beta-hemolytic streptococci (BHS) are an uncommon cause of infective endocarditis (IE). The aim of this study was to describe the clinical features and outcomes of patients with BHS IE in a large multinational cohort and compare them with patients with viridans streptococcal IE. METHODS: The International Collaboration on Endocarditis Prospective Cohort Study (ICE-PCS) is a large multinational database that recruited patients with IE prospectively using a standardized data set. Sixty-four sites in 28 countries reported patients prospectively using a standard case report form developed by ICE collaborators. RESULTS: Among 1336 definite cases of streptococcal IE, 823 were caused by VGS and 147 by BHS. Patients with BHS IE had a lower prevalence of native valve (P < .005) and congenital heart disease predisposition (P = .002), but higher prevalence of implantable cardiac device predisposition (P < .005). Clinically, they were more likely to present acutely (P < .005) and with fever (P = .024). BHS IE was more likely to be complicated by stroke and other systemic emboli (P < .005). The overall in-hospital mortality of BHS IE was significantly higher than that of VGS IE (P = .001). In univariate analysis, variables associated with in-hospital mortality for BHS IE were age (odds ratio [OR], 1.044; P = .004), prosthetic valve IE (OR, 3.029; P = .022), congestive heart failure (OR, 2.513; P = .034), and stroke (OR, 3.198; P = .009). CONCLUSIONS: BHS IE is characterized by an acute presentation and higher rate of stroke, systemic emboli, and in-hospital mortality than VGS IE. Implantable cardiac devices as a predisposing factor were more often found in BHS IE compared with VGS IE.

Colonization of ß-hemolytic streptococci in patients with erysipelas-a prospective study.

Erysipelas is a common skin infection causing significant morbidity. At present there are no established procedures for bacteriological sampling. Here we investigate the possibility of using cultures for diagnostic purposes by determining the perianal colonization with beta-hemolytic streptococci (BHS) in patients with erysipelas. Patients with erysipelas and a control group of patients with fever without signs of skin infection were prospectively included and cultures for BHS were taken from the tonsils, the perianal area, and wounds. BHS were grouped according to Lancefield antigen, species-determined, and emm-typed. Renewed cultures were taken after four weeks from patients with erysipelas and a positive culture for BHS. 25 patients with erysipelas and 25 with fever were included. In the group with erysipelas, 11 patients (44%) were colonized with BHS, ten patients were colonized in the perianal area, and one patient in the throat. In contrast, only one patient in the control group was colonized (p = 0.005 for difference). All of the patients with erysipelas colonized with BHS had an erythema located to the lower limb. The BHS were then subjected to MALDI-TOF MS and most commonly found to be Streptococcus dysgalactiae. Renewed cultures were taken from nine of the 11 patients with BHS and three of these were still colonized. Streptococcus dysgalactiae colonizes the perianal area in a substantial proportion of patients with erysipelas. The possibility of using cultures from this area as a diagnostic method in patients with erysipelas seems promising.

Differences in gram-positive bacterial colonization and antimicrobial resistance among children in a high income inequality setting.

BACKGROUND: Staphylococcus aureus and beta-hemolytic streptococci (BHS) diseases disproportionately affect populations in middle/low-income countries. To assess if this disparity is reflected in colonization by these organisms, we compared their colonization frequency among children from different socioeconomic status (SES) communities in a city with high income inequality. METHODS: Between May-August 2014, we collected nasal and throat swabs to investigate S. aureus and BHS colonization among children who attended private and public pediatric clinics. Patients were classified as high SES, middle/low SES, and slum residents. We investigated the antimicrobial resistance profile, the SCCmec types and the presence of PVL genes among methicillin-resistant S. aureus (MRSA). We also examined the antimicrobial resistance profile and serogroups of BHS. RESULTS: Of 598 children, 221 (37%) were colonized with S. aureus, of which 49 (22%) were MRSA. MRSA colonization was higher in middle/low SES (n = 18; 14%) compared with high SES (n = 17; 6%) and slum (n = 14; 8%) residents (p = 0.01). All MRSA strains were susceptible to clindamycin, nitrofurantoin, and rifampin. The highest non-susceptibility frequency (42.9%) was observed to erythromycin. SCCmec type V was only found in isolates from high SES children; types I and II were found only in middle/low SES children. Ten (20%) MRSA isolates carried PVL genes. Twenty-four (4%) children were BHS carriers. All BHS (n = 8) found in high SES children and six (67%) isolates from slum patients belonged to group A. All group B streptococci were from middle/low SES children, corresponding to five (71%) of the seven BHS isolated in this group. BHS isolates were susceptible to all drugs tested. CONCLUSIONS: Children from different SES communities had distinct bacterial colonization profiles, including MRSA carriage. Public health officials/researchers should consider SES when assessing disease transmission and control measures.

Panophthalmitis caused by Streptococcus dysgalactiae subsp. equisimilis: A case report and literature review.

Lancefield group G ß-hemolytic Streptococcus dysgalactiae subspecies equisimilis (SDSE) has become a leading causative pathogen of invasive streptococcal infection. In this report, we describe a case of disseminated SDSE infection complicated by endogenous endophthalmitis, resulting in panophthalmitis and blindness. A 65-year-old man who underwent mitral valve replacement surgery two months previously was hospitalized due to high fever and right visual loss. A systemic investigation revealed endophthalmitis complicated by mediastinal abscess, prosthetic infective endocarditis, cerebral emboli and hemorrhage, and multiple arthritis. The patient underwent various surgeries, including vitrectomy, mediastinal lavage, mitral valve replacements, joint lavages, as well as an intensive antibiotic treatment. His general condition gradually improved, but the ocular infection developed to panophthalmitis, which ultimately required ophthalmectomy. A literature review regarding Group G-associated endogenous endophthalmitis suggested that the disease occurs in elderly people, is frequently complicated with endocarditis, and yields poor visual prognosis regardless of appropriate antibiotic treatment and surgical therapies. In this aging society, invasive infections with SDSE should be much more recognized among medical practitioners in order to improve patient prognosis.

Perianal infectious dermatitis: An underdiagnosed, unremitting and stubborn condition.

Perianal infectious dermatitis (PID) represents a superficial inflammation of the perianal skin, which is of bacterial origin (classically, group A beta-hemolytic streptococci). This narrative review aims to critically review and summarize the available scientific literature regarding pediatric PID, being the first of its kind, to the best of the author's knowledge. It also reports the first cases of Romanian children with PID. Multiple databases were subjected to systematic literature search (from 1966 to April 30, 2018) to identify studies and case reports of children with PID. As such, this review provides updated information about essential aspects of PID (epidemiology, etiology, pathogenesis, as well as clinical features, required investigations and therapeutic options) and of diagnostic pitfalls. Although a well-defined entity, PID remains largely underdiagnosed. PID may mimic other common conditions with skin manifestations (like candidiasis, pinworms, eczema, irritant dermatitis, anal fissure, hemorrhoids, Crohn's disease, psoriasis, seborrheic dermatitis, zinc deficiency dermatosis and even sexual abuse), with consequent unnecessary, sometimes expensive and invasive investigations and futile therapies, which cause patients and families discomfort and distress. Since PID has an unremitting course, early recognition is imperative, as it allows for prompt and efficacious antibiotic therapy. However, PID represents a stubborn condition and, even if properly treated, its recurrence rate remains high. Further well-designed prospective randomized controlled trials, with adequate follow-up, are required in order to formulate the optimum personalized antibiotic therapy (oral alone or in association with topical medication), able to prevent recurrences. Awareness of this condition by healthcare professionals should improve patient outcomes.

Clinical outcomes in patients hospitalized with cellulitis treated with oral clindamycin and trimethoprim/sulfamethoxazole: The role of weight-based dosing.

OBJECTIVES: Trimethoprim/sulfamethoxazole (TMP/SMX) and clindamycin are frequently prescribed to treat cellulitis. The primary objective was to determine if weight-based dosing of these antibiotics is associated with better outcomes in cellulitis. The secondary objective was to assess variables associated with clinical failure among hospitalized patients with cellulitis with or without cutaneous abscess. METHODS: This multi-center retrospective cohort study was conducted from January 1, 2010 to September 4, 2014. Adult patients admitted for cellulitis who received a minimum of seven days of therapy and discharged on oral clindamycin or TMP/SMX were included. Binary univariate and multivariate logistic regression analyses were performed to identify risk factors for clinical failure, including the impact of dose adequacy of clindamycin and TMP/SMX on clinical outcomes. RESULTS: A total of 208 cases met inclusion criteria. Of these cases, 120 (57.7%) received inadequate dosing of clindamycin (<10 mg/kg/day) or TMP/SMX (<5 mg TMP/kg per day) while 88 (42.3%) received adequate dosing. Clinical failure occurred in 36/120 (30%) and 15/88 (17%) of patients receiving inadequate and adequate doses, respectively (p = 0.032). Upon univariate analysis length of stay ≥ 7 days (OR = 2.96, p = 0.046) and inadequate dosing (OR = 2.09, p = 0.034) were associated with clinical failure. Upon multivariate analysis, inadequate dosing was independently associated with clinical failure (OR = 2.01, p = 0.032). CONCLUSION: Inadequate dosing of clindamycin and TMP/SMX is independently associated with clinical failure in patients hospitalized with cellulitis. Further prospective studies evaluating weight-based dosing of clindamycin and TMP/SMX in the setting of cellulitis are warranted.

Throat culture positivity rate and antibiotic susceptibility pattern of beta-hemolytic streptococci in children on secondary prophylaxis for rheumatic heart disease.

BACKGROUND: Among children diagnosed to have chronic rheumatic valvular heart disease (RHD) in Ethiopia, many have been observed to develop recurrence of rheumatic fever (RF) despite secondary prophylaxis. This study determined the throat culture positivity rate and drug susceptibility pattern of beta hemolytic streptococci (BHS) isolated from children attending a specialized cardiac clinic in Ethiopia. METHODS: Throat swabs were collected from 233 children receiving benzathine penicillin injection as secondary prophylaxis for RHD and cultured. The bacterial isolates were characterized using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry. Drug susceptibility was tested with the Kirby Bauer disc diffusion method. Anti-streptolysin O (ASO) titers were determined using ASO latex reagents. RESULTS: The throat culture positivity rate for BHS was 24 % (56/233). Among the BHS bacterial strains isolated, four were characterized as S. pyogenes and another four as S. dysgalactiae subsp. equisimilis (Lancefield group A, C and G). All BHS were susceptible to penicillin except one isolate of S. agalactiae. Among 233 children enrolled, 46(19.7 %) showed increased ASO titer. Children who received antibiotic prophylaxis within 2-weeks of last injection had significantly lower BHS throat culture positivity rate than those injected every 4-weeks (p = 0.02). Children who missed at least one prophylaxis within the last 6 months had a higher BHS culture positivity rate than those who did not miss any (p = 0.0003). CONCLUSIONS: The presence of groups A, C and G streptococci in the throat of children under secondary prophylaxis for RHD and increased ASO titer suggests failure of the regimen. This calls for further investigation into the causes of inadequate prophylaxis (including bioavailability of drugs used, optimal duration and patient compliance) and intervention.

Traumatic endophthalmitis following a crane pecking injury - An unusual mode.

PURPOSE: To report a case of beta-hemolytic streptococcal endophthalmitis following crane-pecking injury. CASE REPORT: A twelve-year-old boy was brought to us by his father with history of crane beak injury in his right eye. On examination, his vision was 6/24 Snellen's acuity. Anterior segment examination showed a full thickness two mm corneo-limbal tear at 1 o'clock with iris prolapse. Pupil showed peaking through the wound with a clear crystalline lens. There was no evidence of hypopyon in the anterior chamber and B-scan ultrasonography showed acoustically clear vitreous with an attached retina. Left eye was within normal limits. Primary corneo-limbal tear repair was performed within 24 hours from the time of presentation. Intra-operatively, the corneal surgeon noted turbid aqueous with minimal hypopyon. In view of clinical suspicion of infection, an intravitreal tap for culture was taken during the primary repair, and prophylactic intravitreal antibiotics were given. The culture report showed beta-hemolytic streptococci. Pars plana vitrectomy with intravitreal antibiotics was performed after 2 days as serial ultrasound scans showed appearance and worsening of endophthalmitis. A month after the surgery, his best corrected visual acuity improved to 6/12. CONCLUSION: Ocular injuries resulting from bird pecking are very rare. We treated a case of full thickness corneo-limbal tear with endophthalmitis caused by beta-hemolytic streptococci following a crane-pecking injury. We recommend that injecting intravitreal antibiotics along with primary globe repair in case of severe/contaminated injuries and early pars plana core-vitrectomy would result in better outcome like in our case.

Recurrent bacteremia with Streptococcus dysgalactiae: a case-control study.

Beta-hemolytic streptococci of groups C and G, designated as Streptococcus dysgalactiae (SD), can cause severe and recurring invasive infections. In this case-control study, we aimed to identify clinical and molecular risk factors for recurrence of SD bacteremia. Twenty-two cases of recurrent SD bacteremia were identified, and median time between episodes was 6 months. The most frequent clinical manifestation was skin and soft tissue infection. Cases and 92 controls, with single-episode SD bacteremia, showed similar demographics, had similar Charlson comorbidity scores, and had similar clinical presentations. Thirty-day fatality was 13% among controls, whereas none of 22 cases died. In 19 cases (86%), the same emm type was encountered in both episodes. SD isolates from recurrent episodes and from single episodes had a similar emm type distribution. Thus, we did not identify clinical risk factors for recurrences. The high proportion of identical emm types in recurrent episodes indicates a host-specific colonization.

PREVALENCE, PATHOLOGY, AND RISK FACTORS ASSOCIATED WITH STREPTOCOCCUS PHOCAE INFECTION IN SOUTHERN SEA OTTERS (ENHYDRA LUTRIS NEREIS), 2004-10.

Recent studies have implicated beta-hemolytic streptococci as opportunistic pathogens of marine mammals, including southern sea otters (Enhydra lutris nereis), but little is known about their prevalence or pathophysiology. Herein, we focus on risk factors for sea otter infection by a single beta-hemolytic streptococcal species, Streptococcus phocae. Streptococcus phocae was first identified as a marine mammal pathogen in 1994, and the first report in southern sea otters was in 2009. Its broad host range encompasses fish, pinnipeds, cetaceans, and mustelids, with S. phocae now recognized as an important pathogen of marine species worldwide. We assessed risk factors and lesion patterns for S. phocae infection in southern sea otters. Using archival necropsy data, S. phocae prevalence was 40.5% in fresh dead otters examined 2004-10. Skin trauma of any type was identified as a significant risk factor for S. phocae infection. The risk of infection was similar regardless of the cause and relative severity of skin trauma, including mating or fight wounds, shark bite, and anthropogenic trauma. Streptococcus phocae-infected sea otters were also more likely to present with abscesses or bacterial septicemia. Our findings highlight the importance of S. phocae as an opportunistic pathogen of sea otters and suggest that the most likely portal of entry is damaged skin. Even tiny skin breaks appear to facilitate bacterial colonization, invasion, abscess formation, and systemic spread. Our data provide important insights for management and care of marine species.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the identification of beta-hemolytic streptococci.

OBJECTIVE: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as promising technology for species identification. The purpose of this investigation was to compare the performance of MS and the traditional method for identification of beta-hemolytic streptococci (BHS). METHODS: Clinical BHS isolates were identified by the BD Phoenix SMIC/ID Streptococcal panels, and two MALDI-TOF MS platforms: the VITEK MS and the Bruker MALDI Biotyper systems respectively. In case of discordant results, 16sRNA sequencing was performed to provide the reference ID. RESULTS: A total of 96 isolates of BHS were analyzed. Thirty-six isolates (20.8%) were re-tested by BD Phoenix for identification failure; and four isolates (4.2%) were rerun on the Bruker system for low identification score. No isolate need a second run for identification by Vitek MS system. Overall, BD Phoenix, BioTyper and Vitek MS automated system accurately identified 76 strains (79.2%), 91 (94.7%) strains and 92 (95.8%) strains, respectively. CONCLUSIONS: Our study suggests that MALDI-TOF MS is a superior method to conventional phenotypic methods for BHS identification.

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry identification of large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G.

BACKGROUND: The aim of this study was to investigate whether large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G can be adequately identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF). Previous studies show varying results, with an identification rate from below 50% to 100%. METHODS: Large colony beta-hemolytic streptococci containing Lancefield groups A, C, and G isolated from blood cultures between January 1, 2007 and May 1, 2012 were included in the study. Isolates were identified to the species level using a combination of phenotypic characteristics and 16s rRNA sequencing. The isolates were subjected to MALDI-ToF analysis. We used a two-stage approach starting with the direct method. If no valid result was obtained we proceeded to an extraction protocol. Scores above 2 were considered valid identification at the species level. RESULTS: A total of 97 Streptococcus pyogenes, 133 Streptococcus dysgalactiae, and 2 Streptococcus canis isolates were tested; 94%, 66%, and 100% of S. pyogenes, S. dysgalactiae, and S. canis, respectively, were correctly identified by MALDI-ToF. DISCUSSION: In most instances when the isolates were not identified by MALDI-ToF this was because MALDI-ToF was unable to differentiate between S. pyogenes and S. dysgalactiae. By removing two S. pyogenes reference spectra from the MALDI-ToF database the proportion of correctly identified isolates increased to 96% overall. MALDI-ToF is a promising method for discriminating between S. dysgalactiae, S. canis, and S. equi, although more strains need to be tested to clarify this.