Lancefield Classification Research Articles

Lancefield classification and antimicrobial resistance of hemolytic streptococci isolated from bovine mastitis.

Streptococcal species are known to be responsible for bovine mastitis. The aim of the present study was to determine antimicrobial drug resistance patterns of hemolytic streptococci distributed according to Lancefield serogrouping. Streptococcus sp. strains were isolated from 124 bovine milk samples from 31 cows with subclinical or clinical mastitis submitted to Mehmet Akif Ersoy University Faculty of Veterinary Medicine, Department of Microbiology Laboratory in Burdur province, Turkey from January 2015 to January 2017. A total of 63 Streptococcus sp. were isolated and the most frequently obtained isolates were classified as Lancefield's serogroup B (84.13%), the remaining isolates as serogroup F (15.87%). Out of 63 isolates, 53 (84.13%) showed beta‑hemolytic activity whereas 10 (15.87%) alpha‑hemolytic activity. Antimicrobial resistance was assessed by disk diffusion test against the most common antibiotics used in the field. Among the 63 Streptococcus sp. tested, the highest antimicrobial resistance patterns were observed for neomycin (95.24%), trimethoprim sulphamethoxazole (87.30%) and gentamicin (69.84%). None of the isolates showed resistance to amoxicillin‑clavulanic acid, except for one serogroup F isolate. The resistance rates for the other antimicrobials ranged from 1.59% to 38.04%. A total of 50 isolates exibited multi‑drug resistance to ≥ 3 antimicrobial agents tested. Overall, our results suggested that there is an urgent need to enhance awareness among the dairy farmers in choosing the appropriate drug for treating mastitis.

Isolation and molecular detection of Streptococcus agalactiae from popped eye disease of cultured Tilapia and Vietnamese koi fishes in Bangladesh.

ObjectivePresent research aims to isolate, identify, and determine the virulence of the Streptococcus agalactiae (group B Streptococcus; GBS), isolated from popped eye disease affected Tilapia and Vietnamese Koi (V. Koi) fishes.Materials and MethodsA total of 330 fish samples were collected, of which Tilapia (n = 180) and V. Koi (n = 150), were collected from 35 affected ponds of four selected districts of Bangladesh. Isolation of the bacterium was done using different culture media (Nutrient broth, Plate count agar, Tryptic Soy Agar, and Blood agar), and identification by using various biochemical tests (conventional and using API 20 Strep kit) and polymerase chain reaction (PCR) using primers against 16S rRNA gene of S. agalactiae. Antibiotic susceptibility of the bacteria was performed using seven different antibiotics disc (Tetracycline, Oxytetracycline, Chlortetracycline, Streptomycin, Ciprofloxacin, Gentamicin, and Neomycin). Virulence of the isolated S. agalactiae was determined by infecting healthy Tilapia and V. Koi fishes through experimental infection.ResultsIsolated bacteria were found Gram-positive paired and chained cocci, β-hemolytic and non-motile. Findings of biochemical and serological tests indicate that the isolated bacterium belongs to Group B Streptococcus of Lancefield classification. PCR result also confirmed that the bacteria were S. agalactiae. The bacterial isolates possessed resistance property against all the seven antibiotics used in this study. The isolated GBS was found highly virulent and showed 80%–90% mortality for Tilapia and V. Koi fishes in experimental infection within 1–6 days of post-infection.ConclusionFrom the findings of this study, it may be concluded that isolated GBS from the Tilapia and V. Koi fishes were highly virulent and possessed multidrug-resistance properties.

Unexpected fatal empyema in a previously healthy woman

Streptoccoccus pyogenes is gram + aerob coccus and it is described as group A Streptococcus (GAS) according to the Lancefield classification. GAS may cause pneumonia and pleural effusion rarely.Herein we reported a 43 years old previously healthy woman presented to the Emergency Department (ED) with the complaint of chest-back pain and shortness of breath. During her follow up she developed septic shock due to the empyema. 13rd hour of her admission, cardiopulmonary arrest developed and she died in spite of the appropriate and immediate treatment. 2 days later after her admission, streptoccoccus pyogenes was detected in her pleural effusion and blood culture. In conclusion clinicians should be aware of this potential fatal condition also in healthy patients and start the treatment immediately.

Streptococcus dysgalactiae subsp. equisimilis Isolated From Infections in Dogs and Humans: Are Current Subspecies Identification Criteria accurate?

Streptococcus dysgalactiae is a pyogenic species pathogenic both for humans and animals. Until recently, it has been considered an exclusive animal pathogen causing infections in wild as well as domestic animals. Currently, human infections are being reported with increasing frequency, and their clinical picture is often similar to the ones caused by Streptococcus pyogenes. Due to the fact that S. dysgalactiae is a heterogeneous species, it was divided into two subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD). The first differentiation criterion, described in 1996, was based on strain isolation source. Currently applied criteria, published in 1998, are based on hemolysis type and Lancefield group classification. In this study, we compared subspecies identification results for 36 strains isolated from clinical cases both in humans and animals. Species differentiation was based on two previously described criteria as well as MALDI-TOF and genetic analyses: RISA and 16S rRNA genes sequencing. Antimicrobial susceptibility profiles were also determined according to CLSI guidelines. The results presented in our study suggest that the subspecies differentiation criteria previously described in the above two literature positions seem to be inaccurate in analyzed group of strains, the hemolysis type on blood agar, and Lancefield classification should not be here longer considered as criteria in subspecies identification. The antimicrobial susceptibility tests indicate emerging of multiresistant human SDSE strains resistant also to vancomycin, linezolid and tigecycline, which might pose a substantial problem in treatment.

Artritis piógena por Streptococcus agalactiae. Aportación de cuatro casos y revisión de la literatura

Most infections by group B streptococcus of the Lancefield classification ( Streptococcus agalactiae), were reported in pregnant women or during the puerperal period, as well as in neonates. During the past three decades there have been reports of increasingly invasive infections in adults unrelated to pregnancy, although arthritis and osteomyelitis are still very rare. In this article, we describe four new adult patients with arthritis by S. agalactiae (two postmenopausal women and two men), two of them with affection of the sternoclavicular joint. We also review the medical literature.

Streptococcus equi Primary Bacteremia in a Hepatitis-C Cirrhotic Patient

Streptococcus equi belongs to the pyogenic group of Streptococci and to group C of the Lancefield classification. These are bacteria typically associated with disease in animals but are emerging as important human pathogens. It consists of three subspecies of zoonotic agents, Streptococcus equisimilis, Streptococcus zooepidemicus, and Streptococcus dysgalactiae. We report a case of primary bacteremia caused by S. equi subsp. Zooepidemicus in a chronic hepatitis C patient awaiting liver transplantation. This has not been previously recognized as an infectious agent in this context. Case Report A 49-year-old White male with medical history of systemic hypertension, type II diabetes mellitus, and chronic hepatitis C virus liver disease was admitted to hospital with a change in mental status. He was diagnosed with hepatitis C virus (genotype 1a) cirrhosis approximately 2 years previously. He was a donkey breeder by occupation and had multiple abrasions on his hands and arms. At the time of admission, he was febrile to 102 F, with otherwise normal vital signs. There were no symptoms or signs of neurological deficit suggestive of stroke. Laboratory investigations revealed the following: leukocyte count 9700/mm3, hemoglobin level 16.4 g/dL, platelet count 58,000/mm3, glucose 193 mg/dL, total bilirubin 1.9 mg/dL, alkaline phosphatase 173 IU/L, aspartate aminotransferase 113 IU/L, alanine aminotransferase 146 IU/L, and blood ammonia levels of 36 μg/dL. Lumbar puncture, diagnostic paracentesis, and urine analysis were unremarkable. Blood cultures were obtained, and he was started on broad spectrum antibiotics. Blood cultures were positive for catalase-negative, β-hemolytic, gram-positive Streptococcus equi subsp. zooepidemicus. The bacterium was susceptible to ampicillin, cefazolin, clindamycin, erythromycin, levofloxacin, penicillin-G, trimethoprim, and vancomycin. Patient recovered well with a 2-week course of levofloxacin. Group C β-hemolytic Streptococci have been identified as part of the normal human flora of the nasopharynx, skin, and genital tract; the organism has also been cultured from umbilical specimens in newborns and in routine puerperal vaginal cultures. The three different species of group C Streptococci differ in their biochemical characteristics. Streptococcus equi subsp. zooepidemicus ferments sorbitol but not trehalose, produces a novel hemolysin but not streptolysin O or S, does not produce streptokinase, and is an uncommon human pathogen (1). Infections reported include pharyngitis, cellulitis, puerperal sepsis, urinary tract infection, epiglottitis, sinusitis, meningitis, intraabdominal abscesses, pneumonitis, pericarditis, endocarditis, poststreptococcal glomerulonephritis, primary bacteremia (2), and epidural abscess. Cases of bacteremia of unknown source have also been observed in neutropenic patients with underlying leukemia and dialysis-associated infection (3). Risk factors, such as chronic cardiopulmonary disease, malignancy, chronic dermatologic conditions, long term immunosuppressive therapy and alcoholism, have been reported to predispose to group C Streptococcal infection (3, 4). In this case, hepatitis C virus cirrhosis was presumably the predisposing condition. This association has never been reported previously. Human infections caused by S. equi subsp. equi, and S. equi subsp. zooepidemicus have been reported in outbreaks of food borne diseases or prior exposure to animals (5, 6). In this case, the source of patient’s infection was most likely his occupational exposure as a donkey breeder. Prior exposure to animals can be traced only in 24% of human infections (4). Himanshu Aggarwal Department of Surgery Duke University Medical Center Durham, NC Alastair D. Smith Department of Medicine Duke University Medical Center Durham, NC Paul C. Kuo Deepak S. Vikraman Department of Surgery Duke University Medical Center Durham, NC

FatalStreptococcus equisubsp.ruminatorumInfection in a Man

Fatal<i>Streptococcus equi</i>subsp.<i>ruminatorum</i>Infection in a Man

Streptococcus canis infections in humans: Retrospective study of 54 patients

This 5-year retrospective study reports 54 patients with infection, caused by Streptococcus canis, a pyogenic Lancefield group G streptococcus initially isolated from various animal sources. During 1997-2002, Streptococcus canis accounted for 1% of all streptococci isolated. The clinical signs, outcome and bacteriological characteristics were reviewed. All except eight were symptomatic. Clinical manifestations were: soft tissue infection (n=35), bacteremia (n=5), urinary infection (n=3), bone infection (n=2) and pneumonia (n=1). The course was favorable in 52 cases while two died from sepsis. Cultures were often polymicrobial (n=42, 77.8%) apart from hemocultures. The isolates were sensitive to most antibiotics. Presence of the bacteria did not always signify infection owing to the possible occurrence of colonization. The frequency of S. canis infections is rare and likely underestimated owing to the fact that streptococci are sought only on the basis of the Lancefield classification. The search for S. canis is recommended whenever patients present with symptoms evocative of exposure to a potentially contaminated animal.

Extension of the Lancefield Classification for Group A Streptococci by Addition of 22 New M Protein Gene Sequence Types from Clinical Isolates: emm103 to emm124

Classic M protein serotyping has been invaluable during the past 60 years for the determination of relationships between different group A streptococci (GAS) strains and the varied clinical manifestations inflicted by these organisms worldwide. Nonetheless, during the past 20 years, the difficulties of continued expansion of the serology-based Lancefield classification scheme for GAS have become increasingly apparent. By use of a less demanding sequence-based methodology that closely adheres to previously established strain criteria while being predictive of known M protein serotypes, we recently added types emm94-emm102 to the Lancefield scheme. Continued expansion by the addition of types emm103 to emm124 are now proposed. As with types emm94-emm102, each of these new emm types was represented by multiple independent isolates recovered from serious disease manifestations, each was M protein nontypeable with all typing sera stocks available to international GAS reference laboratories, and each demonstrated antiphagocytic properties in vitro by multiplying in normal human blood.

Streptococcal infections of skin and soft tissues.

Streptococcus pyogenes (group A in the Lancefield classification) is one of the most common human pathogens. Although this ubiquitous organism is responsible for a wide array of illnesses, most attention has focused on its relation to acute pharyngitis, because of the frequency of that condition and its potential for inciting acute rheumatic fever. The recent resurgence of invasive group A streptococcal infections,1,2 however, is a reminder that the pathogen can cause a variety of skin and soft-tissue infections, some of which are severe and even life-threatening.Streptococcal PyodermaPyoderma, or impetigo, is a localized, purulent infection of the . . .

Group C streptococcal colonization in a newborn nursery.

An episode of group C streptococcal colonization occurred in a newborn nursery. Because these organisms were sensitive to bacitracin in the concentration used in the disk method, they were presumptively identified as group A streptococci. This was interpreted as the onset of a nursery outbreak of group A streptococcal infection. The presence of bacitracin-sensitive group C streptococci in a potentially significant clinical situation emphasizes the importance of performing Lancefield classification before positively identifying organisms as group A streptococci.

A study on the variation of viridans streptococcus into hemolytic streptococcus in strains isolated from an acute oral suppurative disease.

Most of the bacterial strains isolated from the acute oral diseases are streptococci and staphylococci, and a greater part of these bacteria accounts for hemolytic streptococci. Generally speaking, hemolytic streptococci responsible for the incidence of sup-purative diseases in man are chiefly streptococci pyogenes and they are immunologically representated by Group A of the Lancefield's classification. However, those hemolytic streptococci which are found in the oral suppurative diseases differ greatly in terms of their biological properties from the streptococci pyogenes. As a matter of fact, if we except the fact of hemolysis these hemolytic streptococci are very much similar to those in the viridans group. When examined in terms of their antigen, they do not come under any of Lancefield's A, B, C, D, E and F groups and thus they are rich in the strain specificities. In the previously published researches conducted by the author and his collaborators [1-5], many cases were pointed out which gave rise to a suspicion that these hemolytic streptococci might be variationally derived from viridans streptococci that were invariably found in the infected canal or foci of the root inflammation. This thinking has important bearings on the incidence mechanism of the acute oral suppurative diseases and, as a consequence of a series of experiments, the author has been able to devise a method by means of which streptococci viridans can be variationally changed into hemolytic streptococci as follows.

Teichoic acid and the group antigen of group D streptococci.

THE immunological specificity of carbohydrates in the cell walls of streptococci characterizes groups A, C, E and G in Lancefield's classification of these micro-organisms1–3. Group D is different. Here the cell wall carbohydrate is type-specific, and a component the chemical nature of which has hitherto been in doubt characterizes the group4. The results of the present work indicate that this substance, the group D antigen, is probably a polymer of glucosyl glycerophosphate.

Fibrinolysis of Hemolytic Streptococci and Their Variability

Our interest in the above correlation takes origin as follows: For the past 8 or 9 years one of us (Mellon) has studied with encouraging results a new serum approach to the therapeusis of hemolytic streptococcal infections. Treatment of the cases has been conducted exclusively in this hospital. Accompanying the serum's use we have frequently observed an in vivo dissociation of smooth (or smoothmucoid) cultures into more saprophytic colony types—sometimes characterized by rough-colonied hemolytic streptococci, sometimes by typical non-hemolytic diphtheroids, wholly avirulent. Of special significance is the fact that such dissociation seems to be a direct sequence of a clinical crisis on the part of the severe cases, whose ultimate recovery is thereafter no longer in doubt. Obviously, a serum approach that would transform virulent organisms into their non-virulent phases, is rather different from the conventional bactericidal or antitoxic ones. Only an occasional observer (Hadfield, et al.) in the field of fibrinolysis has directed attention to a correlation of virulence (as indicated by colony type) and fibrinolysis. Recently Tunnicliff has shown correlation in a general way between R and S streptococci with respect to the increasing lysis and virulence as one proceeds from R to S. Reich has shown that serial animal passage transformed a fibrinolytic strain of human origin into a non-fibrinolytic one suggesting a bovine origin; (Lancefield classification), and which on serial subculture returned to its original fibrinolytic state. Accordingly, we have wondered if this correlation might extend to certain variants such as the above; more particularly to diphtheroids whose in vivo dissociation from the streptococci had been confirmed by their occurrence in vitro, under controlled conditions.