Draft Genome Sequence of Streptococcus agalactiae Serotype Ia Strain M19, a Multidrug-Resistant Isolate from a Cow with Bovine Mastitis

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Yang, Feng; Li, Hongsheng; Zhang, Shidong; Wang, Xurong

2016-01-01

Streptococcus agalactiae is a major contagious pathogen causing bovine mastitis worldwide. We report here the draft sequence of S.?agalactiae Ia strain M19, a multidrug-resistant isolate from a bovine mastitis case in Ningxia Hui autonomous region, China.

Human Streptococcus agalactiae strains in aquatic mammals and fish

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2013-01-01

Background In humans, Streptococcus agalactiae or group B streptococcus (GBS) is a frequent coloniser of the rectovaginal tract, a major cause of neonatal infectious disease and an emerging cause of disease in non-pregnant adults. In addition, Streptococcus agalactiae causes invasive disease in fish, compromising food security and posing a zoonotic hazard. We studied the molecular epidemiology of S. agalactiae in fish and other aquatic species to assess potential for pathogen transmission between aquatic species and humans. Methods Isolates from fish (n = 26), seals (n = 6), a dolphin and a frog were characterized by pulsed-field gel electrophoresis, multilocus sequence typing and standardized 3-set genotyping, i.e. molecular serotyping and profiling of surface protein genes and mobile genetic elements. Results Four subpopulations of S. agalactiae were identified among aquatic isolates. Sequence type (ST) 283 serotype III-4 and its novel single locus variant ST491 were detected in fish from Southeast Asia and shared a 3-set genotype identical to that of an emerging ST283 clone associated with invasive disease of adult humans in Asia. The human pathogenic strain ST7 serotype Ia was also detected in fish from Asia. ST23 serotype Ia, a subpopulation that is normally associated with human carriage, was found in all grey seals, suggesting that human effluent may contribute to microbial pollution of surface water and exposure of sea mammals to human pathogens. The final subpopulation consisted of non-haemolytic ST260 and ST261 serotype Ib isolates, which belong to a fish-associated clonal complex that has never been reported from humans. Conclusions The apparent association of the four subpopulations of S. agalactiae with specific groups of host species suggests that some strains of aquatic S. agalactiae may present a zoonotic or anthroponotic hazard. Furthermore, it provides a rational framework for exploration of pathogenesis and host-associated genome content of S

New Mutations of Penicillin-Binding Proteins in Streptococcus agalactiae Isolates from Cattle with Decreased Susceptibility to Penicillin.

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Hu, Yun; Kan, Yunchao; Zhang, Zhengtian; Lu, Zhanning; Li, Yanqiu; Leng, Chaoliang; Ji, Jun; Song, Shiyang; Shi, Hongfei

2018-02-23

Streptococcus agalactiae is a causal agent of bovine mastitis and is treated by β-lactam antibiotics (BLAs). Compared to penicillin-resistant S. agalactiae from humans, resistant strains in bovine are rarely reported. In this study, we aimed to investigate BLA resistance and mutations in penicillin-binding proteins (PBPs) of S. agalactiae in central and northeast China. The minimum inhibitory concentrations (MICs) of 129 penicillin-resistant S. agalactiae isolates from cows with mastitis were determined, and the related PBP genes were detected and sequenced. All strains were unsusceptible to penicillin G and mostly resistant to ampicillin, cefalexin, and ceftiofur sodium. One hundred twenty-nine strains were divided into 4 clonal groups and 8 sequence types by multilocus sequence typing analysis. We found a set of new substitutions in PBP1B, PBP2B, and PBP2X from most strains isolated from three provinces. The strains with high PBP mutations showed a broader unsusceptible spectrum and higher MICs than those with few or single mutation. Our research indicates unpredicted mutations in the PBP genes of S. agalactiae isolated from cows with mastitis treated by BLAs. This screening is the first of S. agalactiae from cattle.

Emerging trends in invasive and noninvasive isolates of Streptococcus agalactiae in a Latin American hospital: a 17-year study.

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Crespo-Ortiz, Maria del Pilar; Castañeda-Ramirez, Claudia Rocio; Recalde-Bolaños, Monica; Vélez-Londoño, Juan Diego

2014-08-03

Streptococcus agalactiae or group B Streptococcus (GBS) has been recognized as a lethal pathogen in neonates worldwide. S. agalactiae infections also severely affect pregnant women and immunosuppressed adults with substantial attributable morbidity and mortality. However, in Latin America, studies on the epidemiology and behaviour of S. agalactiae infections remain limited. To better understand the behaviour of S. agalactiae infections in our region, we conducted a retrospective study to phenotypically describe S. agalactiae isolates collected in one of the largest hospitals in Colombia at two time periods: 1994-2001 and 2004-2012. The isolates were identified by biochemical analysis and tested for antimicrobial susceptibility. In 1994-2001 a total of 201 S. agalactiae isolates were found in urine 38.3%, vaginal exudates 27.8%, soft tissue 12.9%, and blood 8.5%. Susceptibility to ampicillin or penicillin was 94% whereas resistance to erythromycin and clindamycin were 2.8% and 5.2% respectively. In total 46 culture-positive cases of invasive infections were reported, 11 (24%) in neonates and 35 (76%) in adults. In 2004-2012 a total of 671 isolates were found in urine 47.8%, vaginal exudates 32.6%, soft tissue 2.7% and blood 9%. Susceptibility rates to ampicillin and penicillin were 98% whereas resistance to erythromycin and clindamycin were 12.5% and 9.4%. A total of 95 severe infections were reported: 12 (12.6%) were in neonates, 5 (5.3%) in children and 78 (82.1%) in adults. Over the 17-year study period the averaged prevalence of invasive S. agalactiae isolates was 17.4%. The estimated incidence for neonatal infections was 1.34 per 1000 livebirths (0.99 × 1000 livebirths for early- onset disease and 0.35 × 1000 livebirths for late- onset disease) whereas for non-pregnant adults the estimated incidence was 0.75 × 1000 admissions. A remarkable increase in bloodstream infections in immunosuppressed adults and a shift to early neonatal S. agalactiae infections

Comparative genomics analysis of Streptococcus agalactiae reveals that isolates from cultured tilapia in China are closely related to the human strain A909.

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Liu, Guangjin; Zhang, Wei; Lu, Chengping

2013-11-11

Streptococcus agalactiae, also referred to as Group B Streptococcus (GBS), is a frequent resident of the rectovaginal tract in humans, and a major cause of neonatal infection. In addition, S. agalactiae is a known fish pathogen, which compromises food safety and represents a zoonotic hazard. The complete genome sequence of the piscine S. agalactiae isolate GD201008-001 was compared with 14 other piscine, human and bovine strains to explore their virulence determinants, evolutionary relationships and the genetic basis of host tropism in S. agalactiae. The pan-genome of S. agalactiae is open and its size increases with the addition of newly sequenced genomes. The core genes shared by all isolates account for 50 ~ 70% of any single genome. The Chinese piscine isolates GD201008-001 and ZQ0910 are phylogenetically distinct from the Latin American piscine isolates SA20-06 and STIR-CD-17, but are closely related to the human strain A909, in the context of the clustered regularly interspaced short palindromic repeats (CRISPRs), prophage, virulence-associated genes and phylogenetic relationships. We identified a unique 10 kb gene locus in Chinese piscine strains. Isolates from cultured tilapia in China have a close genomic relationship with the human strain A909. Our findings provide insight into the pathogenesis and host-associated genome content of piscine S. agalactiae isolated in China.

Molecular epidemiology of Streptococcus agalactiae isolated from mastitis in Brazilian dairy herds

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Glei A. Carvalho-Castro

Full Text Available Abstract Streptococcus agalactiae is one of the most common pathogens leading to mastitis in dairy herds worldwide; consequently, the pathogen causes major economic losses for affected farmers. In this study, multilocus sequence typing (MLST, genotypic capsular typing by multiplex polymerase chain reaction (PCR, and virulence gene detection were performed to address the molecular epidemiology of 59 bovine (mastitis S. agalactiae isolates from 36 dairy farms located in the largest milk-producing mesoregions in Brazil (Minas Gerais, São Paulo, Paraná, and Pernambuco. We screened for the virulence genes bac, bca, bibA, cfb, hylB, fbsA, fbsB, PI-1, PI-2a, and PI-2b, which are associated with adhesion, invasion, tissue damage, and/or immune evasion. Furthermore, five capsular types were identified (Ia, Ib, II, III, and IV, and a few isolates were classified as non-typeable (NT. MLST revealed the following eight sequence types (STs: ST-61, ST-67, ST-103, ST-146, ST-226, ST-314, and ST-570, which were clustered in five clonal complexes (CC64, CC67, CC103, CC17, and CC314, and one singleton, ST-91. Among the virulence genes screened in this study, PI-2b, fbsB, cfb, and hylB appear to be the most important during mastitis development in cattle. Collectively, these results establish the molecular epidemiology of S. agalactiae isolated from cows in Brazilian herds. We believe that the data presented here provide a foundation for future research aimed at developing and implementing new preventative and treatment options for mastitis caused by S. agalactiae.

Molecular epidemiology of Streptococcus agalactiae isolated from mastitis in Brazilian dairy herds.

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Carvalho-Castro, Glei A; Silva, Juliana R; Paiva, Luciano V; Custódio, Dircéia A C; Moreira, Rafael O; Mian, Glaucia F; Prado, Ingrid A; Chalfun-Junior, Antônio; Costa, Geraldo M

Streptococcus agalactiae is one of the most common pathogens leading to mastitis in dairy herds worldwide; consequently, the pathogen causes major economic losses for affected farmers. In this study, multilocus sequence typing (MLST), genotypic capsular typing by multiplex polymerase chain reaction (PCR), and virulence gene detection were performed to address the molecular epidemiology of 59 bovine (mastitis) S. agalactiae isolates from 36 dairy farms located in the largest milk-producing mesoregions in Brazil (Minas Gerais, São Paulo, Paraná, and Pernambuco). We screened for the virulence genes bac, bca, bibA, cfb, hylB, fbsA, fbsB, PI-1, PI-2a, and PI-2b, which are associated with adhesion, invasion, tissue damage, and/or immune evasion. Furthermore, five capsular types were identified (Ia, Ib, II, III, and IV), and a few isolates were classified as non-typeable (NT). MLST revealed the following eight sequence types (STs): ST-61, ST-67, ST-103, ST-146, ST-226, ST-314, and ST-570, which were clustered in five clonal complexes (CC64, CC67, CC103, CC17, and CC314), and one singleton, ST-91. Among the virulence genes screened in this study, PI-2b, fbsB, cfb, and hylB appear to be the most important during mastitis development in cattle. Collectively, these results establish the molecular epidemiology of S. agalactiae isolated from cows in Brazilian herds. We believe that the data presented here provide a foundation for future research aimed at developing and implementing new preventative and treatment options for mastitis caused by S. agalactiae. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Whole-cell vaccine of Streptococcus agalactiae in Oreochromis sp. with immersion method

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, Sukenda

2015-05-01

Full Text Available ABSTRACT The study was aimed to evaluate the efficacy of formalin-killed non-hemolytic Streptococcus agalactiae N14G and NK1 isolates whole-killed vaccine to prevent streptococcosis in tilapia. Ten fishes were reared in a tank 60x30x35 cm3 with an average body weight at 10.79±0.99 g. Fish was vaccinated through bath immersion at a concentration of 109 cfu/mL. Fish was subsequently challenged by intraperitonial injection of Streptococcus agalactiae 105 cfu/mL at 11 days post-vaccination. Parameters observed were survival, relative percent survival (RPS, total leukocyte, phagocytic activity, antibody titer, total erythrocyte, haemoglobin level, haematocrit level, dan water quality. Samplings were performed in day-0, 20, and 30 after vaccination. Both vaccines have shown higher survival (60% and RPS (40% when challenged with pathogenic Streptococcus N14G isolates than other treatments. Based on RPS percentage observed, those vaccine were still not sufficiently effective to combat S. agalactiae infection. Keywords: tilapia, bath immersion, Streptococcus agalactiae, whole-cell vaccine ABSTRAK Penelitian ini bertujuan untuk mengevaluasi efikasi vaksin formalin-killed cell Streptococcus agalactiae tipe isolat nonhemolitik N14G dan NK1 se utuh yang diberikan melalui perendaman dalam mencegah penyakit streptococcosis pada ikan nila. Ikan nila yang digunakan memiliki bobot 10,79±0,99 g, dipelihara sebanyak sepuluh ekor dalam akuarium ukuran 60x30x35 cm3. Ikan divaksinasi dengan metode perendaman dengan dosis 109 cfu/mL. Uji tantang dilakukan pada hari ke-11 pascavaksinasi dengan dosis 105 cfu/mL. Parameter yang diamati meliputi sintasan (SR, sintasan relatif/relative percent survival (RPS, total leukosit, aktivitas fagositik, titer antibodi, total eritrosit, kadar hemoglobin, kadar hematokrit, dan kualitas air. Pengamatan parameter dilakukan pada hari ke-0, ke-10, ke-20, dan ke-30. Hasil penelitian menunjukkan perlakuan kedua vaksin yang diinfeksi

Infecciones por Streptococcus agalactiae en un servicio de neonatología abierto Infections due to Streptococcus agalactiae at an open neonatology service

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Manuel Díaz Álvarez

2008-12-01

infections due to Streptococcus agalactiae admitted in the Neonatology Service of «Juan M. Márquez» University Pediatric Hospital from February 1992 to December 2007 was conducted. Different clinical and epidemiological variables were processed and analyzed, with calculation of incidence and lethality rates and relation among the categoric variables. RESULTS. There were 76 newborns with infection due to Streptococcus agalactiae for an average annual rate of 1.9 x 100 admissions. It was observed a predominance of late onset infections and of those acquired in the community (89.5 % y 93.4 %, respectively. Meningitis was the most common clinical form followed by isolated bacteriemia. 56 of the 76 newborn infants had bacteriemia (73.7 %. Streptococcus agalactiae showed a high sensitivity to penicillin, erythromycine, vancomycin, cefotaxime and cloranphenicol. There were 7 deaths (9.2 %. All of them had infection of the CNS. CONCLUSIONS. Streptococcus agalactiae is an agent that causes infections affecting the newborn infant, both in the community and in the hospital. These infections may be lethal in some patients with infection of the CNS with o without bacteriemia, even when they maintain a pattern of elevated susceptibility to betalactamic antibiotics.

First report of Streptococcus agalactiae isolated from Oreochromis niloticus in Piura, Peru: Molecular identification and histopathological lesions

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Yessica Ortega Asencios

2016-11-01

Full Text Available The aim of this study was to identify the bacterium Streptococcus agalactiae isolated in farmed Nile tilapia (Oreochromis niloticus from Piura, Peru and to characterize the histopathological lesions caused by this pathogen. Sixteen tilapias were sampled with clinic signs of the disease such as erratic swimming, exophthalmia and haemorrhages on the body and fins. Qualitative PCR in real time and histopathological analysis were performed. Nine fishes positives to S. agalactiae were found. The main histopathological findings were fibrinosuppurative epicarditis, periesplenitis, meninigitis and panophtaltmitis with predominance of mononuclear infiltration in all tissues. The correlation between qPCR and histopathological findings demonstrated nine fish (prevalence of 56.25% with Cq lower than 30, associated to high degree of tissue injuries. This study reports the first isolation of S. agalactiae by PCR in real time in tilapia farmed in Peru and characterizes the major histopathological changes caused by this bacterium.

Biofilm formation, hemolysin production and antimicrobial susceptibilities of Streptococcus agalactiae isolated from the mastitis milk of dairy cows in Shahrekord district, Iran

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Azizollah Ebrahimi

2014-12-01

Full Text Available Streptococcus agalactiae is a major contagious pathogen causing bovine sub-clinical mastitis. The present investigation was carried out to determine some phenotypic characteristics of the S. agalactiae strains isolated from bovine mastitis cases in dairy cows of Shahrekord in the west-center of Iran. One hundred eighty California mastitis test (CMT positive milk samples were bacteriologically studied. A total of 31 (17.2% S. agalactiae isolated. Twenty eight (90.3% of the isolates were biofilm producers. This finding may indicate the high potential of pathogenicity in isolated strains. Sixteen (51.6% isolates were α hemolysin producers. Only 19.3%, 22.5% and 29.0% of the isolates were sensitive to streptomycin, flumequine and kanamycin, respectively. None of these three agents is recommended for treatment of mastitis cases.

Development of live attenuated sparfloxacin-resistant Streptococcus agalactiae polyvalent vaccines to protect Nile tilapia

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To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resi...

Streptococcus agalactiae: an emerging cause of septic arthritis.

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Louthrenoo, Worawit; Kasitanon, Nuntana; Wangkaew, Suparaporn; Hongsongkiat, Sith; Sukitawut, Waraporn; Wichainun, Ramjai

2014-03-01

Invasive Streptococcus agalactiae infection in nonpregnant women has been reported increasingly worldwide. This study reports the clinical features and outcome of S. agalactiae septic arthritis in Thai patients. The medical records of cases with septic arthritis seen between July 1990 and December 2010 were reviewed. Only those with S. agalactiae were included in this study. From 244 cases of septic arthritis, 38 (15.57%, 13 men and 25 women) were caused by S. agalactiae, with 34 of them (89.48%) occurring between 2008 and 2010. Their mean age was 52.89 (SD, 18.95) years. Twenty-four of the 38 patients (63.16%) had 1 or more underlying disease that might predispose to joint infection. Fever and joint pain were the most common symptoms presented. Eleven cases (28.95%) presented monoarthritis, 15 (39.47%) oligoarthritis, and 12 (31.58%) polyarthritis, with a mean joint involvement of 3.34 (SD, 2.35) joints (range, 1-8). Cellulitis was seen in 27 cases (71.05%). Blood cultures were positive in 31 patients (81.58%). Thirty-five of the 38 synovial fluid specimens obtained were enough for cultures and stain smears, with 24 (68.57%) growing S. agalactiae and 19 (54.29%) showing gram-positive cocci. All isolates were sensitive to penicillin. Ten patients (26.31%) received arthroscopic drainage. The articular outcome was good in 11 patients, fair in 24, and poor in 3. There were no deaths. Streptococcus agalactiae is an emerging cause of septic arthritis in Thai patients. Physicians should be especially aware of this condition in patients presenting with acute oligopolyarthritis and prominent cellulitis.

Streptococcus agalactiae infection in cancer patients: a five-year study.

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Pimentel, B A S; Martins, C A S; Mendonça, J C; Miranda, P S D; Sanches, G F; Mattos-Guaraldi, A L; Nagao, P E

2016-06-01

Although the highest burden of Streptococcus agalactiae infections has been reported in industrialized countries, studies on the characterization and epidemiology are still limited in developing countries and implementation of control strategies remains undefined. The aim of this retrospective study was to assess the epidemiological, clinical, and microbiological aspects of S. agalactiae infections in cancer patients treated at a Reference Brazilian National Cancer Institute - INCA, Rio de Janeiro, Brazil. We reviewed the clinical and laboratory records of all cancer patients identified as having invasive S. agalactiae disease during 2010-2014. The isolates were identified by biochemical analysis and tested for antimicrobial susceptibility. A total of 263 strains of S. agalactiae were isolated from cancer patients who had been clinically and microbiologically classified as infected. S. agalactiae infections were mostly detected among adults with solid tumors (94 %) and/or patients who have used indwelling medical devices (77.2 %) or submitted to surgical procedures (71.5 %). Mortality rates (in-hospital mortality during 30 days after the identification of S. agalactiae) related to invasive S. agalactiae infections (n = 28; 31.1 %) for the specific category of neoplasic diseases were: gastrointestinal (46 %), head and neck (25 %), lung (11 %), hematologic (11 %), gynecologic (4 %), and genitourinary (3 %). We also found an increase in S. agalactiae resistance to erythromycin and clindamycin and the emergence of penicillin-less susceptible isolates. A remarkable number of cases of invasive infections due to S. agalactiae strains was identified, mostly in adult patients. Our findings reinforce the need for S. agalactiae control measures in Brazil, including cancer patients.

Incidence and serotype characterisation of Streptococcus agalactiae in a Portuguese hospital.

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Pinto, Ana Mafalda; Pereira, Tamegão Aires; Alves, Valquíria; Araújo, António; Lage, Olga Maria

2018-06-01

Streptococcus agalactiae, commonly known as group B Streptococcus (GBS), has been recognised as a worldwide causative pathogenic agent of neonatal sepsis, meningitis and pneumonia. To better understand the behaviour of S. agalactiae in pregnant women from a hospital from the North of Portugal, retrospective analyses were performed to describe epidemiological, clinical and microbiological characteristics of the isolates obtained. Based on laboratorial records and the hospital's patient files, a 6-year retrospective study was performed to analyse S. agalactiae isolates from screened pregnant women between 35 and 37 weeks of gestation and hospitalised neonates from pregnant women between 24 and 41 weeks of gestation admitted in Hospital Pedro Hispano. Serotype characterisation was also performed in 67 GBS strains. In 6692 pregnant women between 35 and 37 weeks of gestation screened between 2011 and 2016, a total of 1377 S. agalactiae isolates (21%) were found. A high percentage (40%) of unknown colonisation status among hospitalised neonates from pregnant women between 24 and 41 weeks of gestations was also found. The incidence of neonatal sepsis was 8.7 (95% CI 7.0 to 10.8) cases per 1000 live births. Regarding serotype characterisation, serotype III (22.4%) was the most frequent, followed by serotype Ia (19.4%) and serotypes Ib and V (both with 17.9%). High epidemiological values of GBS colonisation and incidence were found in this study. In Portugal studies on the epidemiology and behaviour of S. agalactiae remain limited, reinforcing the importance and need for S. agalactiae screening across the country. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Acute Neonatal Parotitis with Late-Onset Septic Shock due to Streptococcus agalactiae

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M. Boulyana

2014-01-01

Full Text Available Acute neonatal parotitis (ANP is a very rare disease. Most cases are managed conservatively; early antibiotics and adequate hydration may reduce the need for surgery. The most common cause of ANP is Staphylococcus aureus. We report a rare case of acute neonatal parotitis with late-onset septic shock due to Streptococcus agalactiae. The diagnosis was confirmed with ultrasound and isolation of Streptococcus agalactiae from blood culture. The patient was treated successfully with 10 days of intravenous antibiotics and supportive measures. Despite being rare, streptococcal ANP should be considered in the etiological diagnosis of neonatal sepsis. Early diagnosis and appropriate antibiotic might prevent serious complications.

Streptococcus Agalactiae Research on Secretion Vaginal and Anal Pregnant Women of a City of Paulista Northwest

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Cátia Rezende

2015-12-01

Full Text Available Streptococcus agalactiae has great medical importance in infections associated with severe neonatal morbidity and mortality. It is the most frequent bacterium isolated from the tables of septicemia, pneumonia and neonatal meningitis. This study aimed to determine the prevalence of anal and vaginal colonization of S. agalactiae in pregnant women at different gestational ages. We evaluated the incidence of colonization by S. agalactiae in 129 pregnant women of any age. Two samples of secretion were collected for culture: a perianal swab and a vaginal swab. Each of the two swabs were inoculated in test tubes containing Todd-Hewitt broth and subcultured on blood agar. After a period of 24 to 48 hours, the colonies suggestive of S. agalactiae were submitted to morfotintorial analysis and to biochemical tests for identification. Among 129 women studied, 3 (2.33% have tested positive for Streptococcus agalactiae and 126 (97.67% were negative. The results presented in this work are inferior to the data from other studies, however, the methodology used was compatible with most authors. Even so this rate is considered a relevant value taking into account the importance of Streptococcus agalactiae infections in pregnant women and newborns, emphasizing the importance of encouraging the culture of vaginal and anal secretion for the detection of Streptococcus agalactiae in surveys of prenatal care.

The Evaluation of Antibacterial Activity (Streptococcus agalactiae by Using Mahkota Dewa Extract (Phaleria macrocarpa L. with Diffirent Solvent

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Lutfiana Safitri

2017-07-01

Full Text Available This research was aimed to determine the antibacterial activity of mahkota dewa extract and the effective concentration of mahkota dewa extract against Streptococcus agalactiae. This research was conducted from 2Mayth to 2Juneth 2016. The material ware Streptococcus agalactiae bacteria which isolated from mastitis milk, mahkota dewa which extracted using Aquades and ethanol. The method design was experiment research using Nested Design with 6 treatments and 5 replications. The concentrations of the treatments were P1 (10%, P2 (20%, P3 (30%, P4 (40% and P5 (50% and positive control P0 (iodips 10%. The collected data were analyzed using the analysis of variance indicated the significant effects, the least significant different test (LSD was then employed. Mahkota dewa extract using ethanol (50% result showed that significantly (P<0.01 on growth of Streptococcus agalactiae was 20.34± 0.92mm. Mahkota dewa extract using aquades (50% result showed that significantly (P<0.01 on growth of Streptococcus agalactiae was 10.0 ± 0.50 mm. The conclusion of this research is Mahkota dewa fruits extract with ethanol had inhibitory higher in habiting the Streptococcus agalactiae bacteria compared to aquades solvent. The best of treatment of Mahkota dewa fruits extract with ethanol and Aquades solvent in concentration 50% had a high ability to inhibit the growth of Streptococcus agalactiae.

The genetic diversity and phenotypic characterisation of Streptococcus agalactiae isolates from Rio de Janeiro, Brazil

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Ana Beatriz de Almeida Corrêa

2011-12-01

Full Text Available Streptococcus agalactiae isolates are more common among pregnant women, neonates and nonpregnant adults with underlying diseases compared to other demographic groups. In this study, we evaluate the genetic and phenotypic diversity in S. agalactiae strains from Rio de Janeiro (RJ that were isolated from asymptomatic carriers. We analysed these S. agalactiae strains using pulsed-field gel electrophoresis (PFGE, serotyping and antimicrobial susceptibility testing, as well as by determining the macrolide resistance phenotype, and detecting the presence of the ermA/B, mefA/E and lnuB genes. The serotypes Ia, II, III and V were the most prevalent serotypes observed. The 60 strains analysed were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampin and tetracycline was observed. Among the erythromycin and/or clindamycin resistant strains, the ermA, ermB and mefA/E genes were detected and the constitutive macrolides, lincosamides and streptogramin B-type resistance was the most prevalent phenotype observed. The lnuB gene was not detected in any of the strains studied. We found 56 PFGE electrophoretic profiles and only 22 of them were allocated in polymorphism patterns. This work presents data on the genetic diversity and prevalent capsular serotypes among RJ isolates. Approximately 85% of these strains came from pregnant women; therefore, these data may be helpful in developing future prophylaxis and treatment strategies for neonatal syndromes in RJ.

Prophagic DNA Fragments in Streptococcus agalactiae Strains and Association with Neonatal Meningitis

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van der Mee-Marquet, Nathalie; Domelier, Anne-Sophie; Mereghetti, Laurent; Lanotte, Philippe; Rosenau, Agnès; van Leeuwen, Willem; Quentin, Roland

2006-01-01

We identified—by randomly amplified polymorphic DNA (RAPD) analysis at the population level followed by DNA differential display, cloning, and sequencing—three prophage DNA fragments (F5, F7, and F10) in Streptococcus agalactiae that displayed significant sequence similarity to the DNA of S. agalactiae and Streptococcus pyogenes. The F5 sequence aligned with a prophagic gene encoding the large subunit of a terminase, F7 aligned with a phage-associated cell wall hydrolase and a phage-associated lysin, and F10 aligned with a transcriptional regulator (ArpU family) and a phage-associated endonuclease. We first determined the prevalence of F5, F7, and F10 by PCR in a collection of 109 strains isolated in the 1980s and divided into two populations: one with a high risk of causing meningitis (HR group) and the other with a lower risk of causing meningitis (LR group). These fragments were significantly more prevalent in the HR group than in the LR group (P S. agalactiae strains to invade the neonatal brain endothelium. We then determined the prevalence of F5, F7, and F10 by PCR in a collection of 40 strains recently isolated from neonatal meningitis cases for comparison with the cerebrospinal fluid (CSF) strains isolated in the 1980s. The prevalence of the three prophage DNA fragments was similar in these two populations isolated 15 years apart. We suggest that the prophage DNA fragments identified have remained stable in many CSF S. agalactiae strains, possibly due to their importance in virulence or fitness. PMID:16517893

Antibacterial activity and mechanism of berberine against Streptococcus agalactiae.

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Peng, Lianci; Kang, Shuai; Yin, Zhongqiong; Jia, Renyong; Song, Xu; Li, Li; Li, Zhengwen; Zou, Yuanfeng; Liang, Xiaoxia; Li, Lixia; He, Changliang; Ye, Gang; Yin, Lizi; Shi, Fei; Lv, Cheng; Jing, Bo

2015-01-01

The antibacterial activity and mechanism of berberine against Streptococcus agalactiae were investigated in this study by analyzing the growth, morphology and protein of the S. agalactiae cells treated with berberine. The antibacterial susceptibility test result indicated minimum inhibition concentration (MIC) of berberine against Streptococcus agalactiae was 78 μg/mL and the time-kill curves showed the correlation of concentration-time. After the bacteria was exposed to 78 μg/mL berberine, the fragmentary cell membrane and cells unequal division were observed by the transmission electron microscopy (TEM), indicating the bacterial cells were severely damaged. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) study demonstrated that berberine could damage bacterial cells through destroying cellular proteins. Meanwhile, Fluorescence microscope revealed that berberine could affect the synthesis of DNA. In conclusion, these results strongly suggested that berberine may damage the structure of bacterial cell membrane and inhibit synthesis of protein and DNA, which cause Streptococcus agalactiae bacteria to die eventually.

Development of live attenuated Streptococcus agalactiae as potential vaccines by selecting for resistance to sparfloxacin.

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Pridgeon, Julia W; Klesius, Phillip H

2013-05-31

To develop attenuated bacteria as potential live vaccines, sparfloxacin was used in this study to modify 40 isolates of Streptococcus agalactiae. Majority of S. agalactiae used in this study were able to develop at least 80-fold resistance to sparfloxacin. When the virulence of the sparfloxacin-resistant S. agalactiae isolates were tested in 10-12g Nile tilapia by intraperitoneal injection at dose of 2×10(7)CFU/fish, 31 were found to be avirulent to fish. Of the 31 avirulent sparfloxacin-resistant S. agalactiae isolates, 30 provided 75-100% protection to 10-12g Nile tilapia against challenges with a virulent S. agalactiae isolate Sag 50. When the virulence of the 30 sparfloxacin-resistant S. agalactiae isolates was tested in 3-5g Nile tilapia by intraperitoneal injection at dose of 2×10(7)CFU/fish, six were found to be avirulent to 3-5g Nile tilapia. Of the six avirulent sparfloxacin-resistant S. agalactiae isolates, four provided 3-5g Nile tilapia 100% protection against challenges with homologous isolates, including Sag 97-spar isolate that was non-hemolytic. However, Sag 97-spar failed to provide broad cross-protection against challenges with heterologous isolates. When Nile tilapia was vaccinated with a polyvalent vaccine consisting of 30 sparfloxacin-resistant S. agalactiae isolates at dose of 2×10(6)CFU/fish, the polyvalent vaccine provided significant (PS. agalactiae. Taken together, our results suggest that a polyvalent vaccine consisting of various strains of S. agalactiae might be essential to provide broader protection to Nile tilapia against infections caused by S. agalactiae. Published by Elsevier Ltd.

Culture-Negative Neonatal Meningitis and Endocarditis Caused by Streptococcus agalactiae

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Nègre, Valérie Lefranc; Colin-Gorski, Anne-Marie; Magnier, Suzel; Maisonneuve, Lydia; Aujard, Yannick; Bingen, Edouard; Bonacorsi, Stéphane

2004-01-01

We describe a case of culture-negative meningitis and endocarditis caused by Streptococcus agalactiae in a 27-day-old boy. S. agalactiae was detected in cerebrospinal fluid and serum by broad-spectrum PCR amplification.

Meningoencephalitis in farmed monosex Nile tilapia (Oreochromis niloticus L. caused by Streptococcus agalactiae

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Adikesavalu Harresh

2017-09-01

Full Text Available Aquaculture of tilapia is a new research venture in India. With intensification in farming practices, tilapia are increasingly susceptible to bacterial infections. This article describes the isolation and identification of pathogenic bacteria from cultured monosex Nile tilapia, Oreochromis niloticus (L., that experienced moderate to severe mortalities in West Bengal, India between September and August 2014 and histopathological alterations in various organs. Gram-positive diplococci, identified as Streptococcus agalactiae with Streptococcus identification kits and 16S rDNA sequencing analysis, were isolated from the brain, operculum, and kidney. Other bacteria from the kidney were identified as Aeromonas sobria, A. caviae, Klebsiella pneumoniae ssp. pneumoniae, Escherichia coli, and Enterobacter cloacae. Staphylococcus epidermis was isolated from opercular hemorrhages. Histological sections of the infected tilapia brain revealed meningoencephalitis and granulomatous lesions. Sections from other organs indicated congestion, hemorrhagic and hyperplastic cells, necrosis, vacuolation, hemosiderin deposition, hypertrophic nuclei, melanomacrophage aggregation, and ruptured veins. This report is the first description of S. agalactiae as a primary pathogen causing meningoencephalitis in cultured tilapia in India.

Antimicrobial resistance and molecular characteristics of Streptococcus agalactiae isolated from women of reproductive age

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Magdalena Musiorska

2016-12-01

Full Text Available Introduction. Streptococcus agalactiae infections are among the most significant causes of neonatal invasive diseases. Proper screening and detection of pregnant women carrying GBS allows intrapartum administration of antibiotic prophylaxis and is an effective measure in preventing transmission of bacteria from mother to newborns. Material and methods. Sixty three bacterial strains were isolated from vaginal swabs from pregnant and nonpregnant women of reproductive age. Species were identified by colony morphology, haemolysis type, Gram staining and SLIDEX® Strepto Plus latex test. Antimicrobial resistance of 56 strains was determined using disk-diffusion method. The presence of molecular resistance determinants was assessed using PCR with specific primers, and capsular types were identified using multiplex PCR. Results. None of the strains were resistant to the first drug of choice, penicillin. A large percentage of isolates (78.6% were resistant to doxycycline. The prevalence of resistance to macrolides and lincosamides, antibiotics used in women allergic to penicillin, was high. Those results corresponded with PCR tests, as tetM and ermA1 were most frequently detected genes (98.4 and 87.3%, respectively. 7.94% of strains possessed 7 different out of 13 tested genes determining resistance to different groups of antimicrobials. Among the capsular types, Ia, which proved to be associated with the most severe and invasive infections in mothers and neonates, was the most prevalent (65.08%. Conclusions. Even though they are susceptible to penicillin, multidrug resistance is common among S. agalactiae strains isolated from women of reproductive age and this resistance can be caused by more than one gene per single isolate

Karakteristik dan Patogenisitas Streptococcus Agalactiae Tipe ?-hemolitik dan Non-hemolitik pada Ikan Nila

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Esti Handayani Hardi

2012-11-01

Full Text Available Streptococcus agalactiae was isolated from cultured Nile tilapia (Oreochromis niloticus in Cirata gulfand Klaten. The isolates were Gram positive cocci, oxidative fermentative positive, motility, and catalasenegative, grown on media containing NaCl 6.5%, ?-haemolytic and non-haemolytic. Two types of S. agalactiae(?-haemolytic and non-haemolytic are different from their variety of sugars fermentation. Strains ?-haemolytic can ferment more sugars, including arabinose, sorbitol, lactose, and trehalose. Experimentalinfectivity trials on Nile tilapia (size 15 g, non-haemolytic type showed more virulent. This type causedfaster mortality, more severe behavior changes, and pathology changes than â-haemolytic type. NonhemoliticS. agalactiae caused 48% mortality 6-24 hours after injection, whereas â-haemolitic type caused17% mortality which it occured in 48 hours after injection (mortality of fish control 2,22%. Behaviordisease signs caused by non-haemolitic S. agalactiae started to happen 6 hours after injection whereas 12hours in ?-haemolytic type infection. Histopatological changes were observed on fish eye, spleen, andbrain. Hyperaemia, hyperthrophi, degeneration, and necrosis were also found on infected fish. Thisresearch was concluded that non-haemolytic of S. agalactiae was more virulent than ?-haemolytic.

nalisis Keragaman Genetik Streptococcus agalactiae Penyebab Mastitis Subklinis Pada Sapi Perah Menggunakan pulsed field gel electrophoresis (PFGE) = Genetic Analysis of Streptococcus agalactiae Caused Subclinical ...

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Trihastuti, Agnesia Endang

2012-01-01

Streptococcus agalactiae atau Streptokokus grup B (SGB) adalah salah satu bakteri utama penyebab mastitis subklinis pada sapi perch dan merupakan parasit obligat pada ambing. Karakterisasi S.agalactiae biasanya dilakukan secara konvensional menggunakan metode serotyping. Meslci metode ini sering digunakan namun masih mempunyai kelemahan apalagi masih adanya isolat S.agalactiae yang belum dapat dimasukkan ke dalam serotipe yang ada (nontypeable/NT), oleh karena itu pendekatan bare denga...

Comparison of transmission dynamics between Streptococcus uberis and Streptococcus agalactiae intramammary infections.

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Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Pinyopummintr, Tanu; Suriyasathaporn, Witaya

2016-02-01

The objectives of study were to determine the transmission parameters (β), durations of infection, and basic reproductive numbers (R0) of both Streptococcus agalactiae and Streptococcus uberis as pathogens causing mastitis outbreaks in dairy herds. A 10-mo longitudinal study was performed using 2 smallholder dairy herds with mastitis outbreaks caused by Strep. agalactiae and Strep. uberis, respectively. Both herds had poor mastitis control management and did not change their milking management during the entire study period. Quarter milk samples were collected at monthly intervals from all lactating animals in each herd for bacteriological identification. The durations of infection for Strep. uberis intramammary infection (IMI) and Strep. agalactiae IMI were examined using Kaplan-Meier survival curves, and the Kaplan-Meier survival functions for Strep. uberis IMI and Strep. agalactiae IMI were compared using log rank survival-test. The spread of Strep. uberis and Strep. agalactiae through the population was determined by transmission parameter, β, the probability per unit of time that one infectious quarter will infect another quarter, assuming that all other quarters are susceptible. For the Strep. uberis outbreak herd (31 cows), 56 new infections and 28 quarters with spontaneous cure were observed. For the Strep. agalactiae outbreak herd (19 cows), 26 new infections and 9 quarters with spontaneous cure were observed. The duration of infection for Strep. agalactiae (mean=270.84 d) was significantly longer than the duration of infection for Strep. uberis (mean=187.88 d). The transmission parameters (β) estimated (including 95% confidence interval) for Strep. uberis IMI and Strep. agalactiae IMI were 0.0155 (0.0035-0.0693) and 0.0068 (0.0008-0.0606), respectively. The R0 (including 95% confidence interval) during the study were 2.91 (0.63-13.47) and 1.86 (0.21-16.61) for Strep. uberis IMI and Strep. agalactiae IMI, respectively. In conclusion, the transmission

Natural coinfection by Streptococcus agalactiae and Francisella noatunensis subsp. orientalis in farmed Nile tilapia (Oreochromis niloticus L.).

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Assis, G B N; Tavares, G C; Pereira, F L; Figueiredo, H C P; Leal, C A G

2017-01-01

Streptococcus agalactiae and Francisella noatunensis subsp. orientalis (Fno) are important pathogens for farm-raised tilapia worldwide. There are no reports of coinfection caused by S. agalactiae and Fno in fish. This study aimed to determine the aetiology of atypical mortalities in a cage farm of Nile tilapia and to characterize the genetic diversity of the isolates. Fifty-two fish were sampled and subjected to parasitological and bacteriological examination. The S. agalactiae and Fno isolates were genotyped using MLST and REP-PCR, respectively. Whole-genome sequencing was performed to confirm the MLST results. Seven fish were shown coinfected by S. agalactiae and Fno. Chronic hypoxia and a reduction in the water temperature were determined as risk factors for coinfection. Fno isolates were shown clonally related in REP-PCR. The MLST analysis revealed that the S. agalactiae isolates from seven coinfected fish were negative for the glcK gene; however, these were determined to be members of clonal complex CC-552. This is the first description of coinfection by S. agalactiae and Fno in farm-raised Nile tilapia. The coinfection was predisposed by chronic hypoxia and was caused by the main genotypes of S. agalactiae and Fno reported in Brazil. Finally, a new S. agalactiae genotype with glcK gene partially deleted was described. © 2016 John Wiley & Sons Ltd.

Streptococcus agalactiae infection in Nile tilapia (Oreochromis niloticus) and its transmission potential to cohabitated sheepshead minnows (Cyprinodon variegatus)

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Streptococcus agalactiae has emerged as an economically important bacterial pathogen affecting global aquaculture. Worldwide aquaculture losses due to S. agalactiae are estimated around U.S. $1 billion, annually. Streptococcus agalactiae also known as a Lancefield Group B Streptococcus (GBS) is a Gr...

Development of Streptococcus agalactiae vaccines for tilapia.

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Liu, Guangjin; Zhu, Jielian; Chen, Kangming; Gao, Tingting; Yao, Huochun; Liu, Yongjie; Zhang, Wei; Lu, Chengping

2016-12-21

Vaccination is a widely accepted and effective method to prevent most pathogenic diseases in aquaculture. Various species of tilapia, especially Nile tilapia Oreochromis niloticus, are farmed worldwide because of their high consumer demand. Recently, the tilapia-breeding industry has been hampered by outbreaks of Streptococcus agalactiae infection, which cause high mortality and huge economic losses. Many researchers have attempted to develop effective S. agalactiae vaccines for tilapia. This review provides a summary of the different kinds of S. agalactiae vaccines for tilapia that have been developed recently. Among the various vaccine types, inactivated S. agalactiae vaccines showed superior protection efficiency when compared with live attenuated, recombinant and DNA vaccines. With respect to vaccination method, injecting the vaccine into tilapia provided the most effective immunoprotection. Freund's incomplete adjuvant appeared to be suitable for tilapia vaccines. Other factors, such as immunization duration and number, fish size and challenge dose, also influenced the vaccine efficacy.

Poliartritis y tenosinovitis grave por Streptococcus agalactiae en un paciente con hipoesplenia funcional Severe polyarthritis and tenosynovitis caused by Streptococcus agalactiae in a patient with functional hyposplenia

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Domingo C. Balderramo

2002-08-01

Full Text Available La artritis por Streptococcus agalactiae es infrecuente. No conocemos publicaciones de casos sobre la afección tendinosa por este microorganismo. Se presenta una mujer de 46 años que consultó por fiebre, poliartralgias, mialgias, diarrea y vómitos. Como antecedentes presentaba carcinoma papilar de tiroides e hipoesplenia funcional. Al examen se encontraba hemodinámicamente inestable, febril, con artritis de mano izquierda, muñecas, codos, hombro derecho y tobillo izquierdo. Presentaba tenosinovitis en ambos pies y en la mano izquierda. Los hemocultivos y el cultivo de la bursa olecraniana derecha fueron positivos para S. agalactiae. La ecografía mostró signos de tenosinovitis del tibial anterior izquierdo. Completó 20 días de tratamiento endovenoso con cefazolina y 12 días de cefuroxima oral. El cuadro articular revirtió completamente en 60 días. El Streptococcus agalactiae puede causar, en forma infrecuente, un síndrome de poliartritis, tenosinovitis y fiebre similar al producido por la infección gonocócica.Cases of arthritis caused by Streptococcus agalactiae are infrequent and in our knowledge there are no case reports of tenosynovitis caused by S. agalactiae. A 46-year-old woman presented with fever, polyarthralgia, myalgia, diarrhea and vomiting. She had a history of papillary thyroid carcinoma and functional hyposplenia. She was febrile, with arthritis in hands, wrists, elbows, right shoulder and left ankle joints, and presented tenosynovitis in both feet and left hand. Blood and right olecranon bursa sample cultures were positive for S. agalactiae. An ultrasound scan made at the musculus tibialis anterior of left foot revealed signs of tenosynovitis. She was treated with intravenous cefazolin for 20 days and oral cefuroxime for 12 days. The joint involvement completely subsided in 60 days. Streptococcus agalactiae can cause, infrequently, a polyarthritis and tenosynovitis syndrome similar to disseminated gonococcal

Complete genome sequence of an attenuated Sparfloxacin resistant Streptococcus agalactiae strain 138spar

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Through selection of resistance to sparfloxacin, an attenuated Streptococcus agalactiae strain 138spar was obtained from its virulent parent strain S. agalactiae 138P. The full genome of S. agalactiae 138spar is 1,838,126 bp. The availability of this genome will allow comparative genomics to identi...

Central nervous system involvement in adult patients with invasive infection caused by Streptococcus agalactiae.

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Oyanguren, B; Esteban, L; Guillán, M; de Felipe, A; Alonso Cánovas, A; Navas, E; Quereda, C; Corral, I

2015-04-01

Streptococcus agalactiae is frequently an asymptomatic coloniser and a cause of neonatal and puerperal sepsis. Infections in nonpregnant adults are uncommon. The frequency of neurological complications caused by invasive infection with this microorganism in adults remains unknown. Here, we study the frequency and characteristics of central nervous system (CNS) involvement in adults with invasive S. agalactiae infection. Review of all adults with invasive S. agalactiae infection between 2003 and 2011 in a tertiary hospital. S. agalactiae was isolated from blood, CSF or synovial fluid in 75 patients. Among them, 7 (9,3%) displayed neurological involvement: 5 men and 2 nonpregnant women, aged between 20 and 62 years. Diagnoses were spinal epidural abscess due to spondylodiscitis with spinal cord compression; acute bacterial meningitis; ischemic stroke as presentation of bacterial endocarditis (2 patients each); and meningoventriculitis after neurosurgery and ventricular shunting. One patient with endocarditis caused by S. agalactiae and S. aureus died in the acute phase, and another died 3 months later from metastatic cancer. The other patients recovered without sequelae. All patients had systemic predisposing factors for infection and 5 (71,4%) had experienced disruption of the mucocutaneous barrier as a possible origin of the infection. CNS involvement is not uncommon in adult patients with invasive infection caused by S. agalactiae. Isolating S. agalactiae, especially in cases of meningitis, should lead doctors to search for predisposing systemic disease and causes of mucocutaneous barrier disruption. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Molecular Characterization of Streptococcus agalactiae Isolates From Pregnant and Non-Pregnant Women at Yazd University Hospital, Iran

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Sadeh, Maryam; Firouzi, Roya; Derakhshandeh, Abdollah; Bagher Khalili, Mohammad; Kong, Fanrong; Kudinha, Timothy

2016-01-01

Background: Streptococcus agalactiae (Group B streptococcus, GBS) that colonize the vaginas of pregnant women may occasionally cause neonatal infections. It is one of the most common causes of sepsis and meningitis in neonates and of invasive diseases in pregnant women. It can also cause infectious disease among immunocompromised individuals. The distribution of capsular serotypes and genotypes varies over time and by geographic era. The serotyping and genotyping data of GBS in Iranian pregna...

Orientation of streptococcus agalactiae irradiation dose for subclinical mastitis vaccine in dairy cows

International Nuclear Information System (INIS)

Tuasikal, B.J.; Estuningsih, S.; Pasaribu, F.H.; Wibawan, I.W.T.

2012-01-01

An experiment to determine the effect of gamma-ray irradiation in debilitating Streptococcus agalactiae as a cause of subclinical mastitis (inflammation of the udder) in cows has been conducted. S. agalactiae bacteria was isolated from subclinical mastitis found in dairy cows in the field was then observed for its cell growth. The bacteria which have reached mid-log phase of growth, were divided into 5 treatment groups, of which each was irradiated at dose level of 0; 25; 50; 75; and 100Gy. Irradiated bacteria subsequently were grown on Brain Heart Infusion agar (BHI), and each of its colonies was counted for LD50 determination. The obtained curves from irradiated treatment bacterial shown viability percentage by the linier equation of Y = 95.414 e -0,0371X ; R 2 = 0.9979, while Y = % viability and X = dose of irradiation. The calculation done in this experiment shows that irradiation dose of 17.4 Gy weaken the bacteria pathogenicity of S. agalactiae to the level of LD 50 . (author)

Discovery and Characterization of Human-Urine Utilization by Asymptomatic-Bacteriuria-Causing Streptococcus agalactiae.

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Ipe, Deepak S; Ben Zakour, Nouri L; Sullivan, Matthew J; Beatson, Scott A; Ulett, Kimberly B; Benjamin, William H; Davies, Mark R; Dando, Samantha J; King, Nathan P; Cripps, Allan W; Schembri, Mark A; Dougan, Gordon; Ulett, Glen C

2016-01-01

Streptococcus agalactiae causes both symptomatic cystitis and asymptomatic bacteriuria (ABU); however, growth characteristics of S. agalactiae in human urine have not previously been reported. Here, we describe a phenotype of robust growth in human urine observed in ABU-causing S. agalactiae (ABSA) that was not seen among uropathogenic S. agalactiae (UPSA) strains isolated from patients with acute cystitis. In direct competition assays using pooled human urine inoculated with equal numbers of a prototype ABSA strain, designated ABSA 1014, and any one of several UPSA strains, measurement of the percentage of each strain recovered over time showed a markedly superior fitness of ABSA 1014 for urine growth. Comparative phenotype profiling of ABSA 1014 and UPSA strain 807, isolated from a patient with acute cystitis, using metabolic arrays of >2,500 substrates and conditions revealed unique and specific l-malic acid catabolism in ABSA 1014 that was absent in UPSA 807. Whole-genome sequencing also revealed divergence in malic enzyme-encoding genes between the strains predicted to impact the activity of the malate metabolic pathway. Comparative growth assays in urine comparing wild-type ABSA and gene-deficient mutants that were functionally inactivated for the malic enzyme metabolic pathway by targeted disruption of the maeE or maeK gene in ABSA demonstrated attenuated growth of the mutants in normal human urine as well as synthetic human urine containing malic acid. We conclude that some S. agalactiae strains can grow in human urine, and this relates in part to malic acid metabolism, which may affect the persistence or progression of S. agalactiae ABU. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Capsule impairs efficient adherence of Streptococcus agalactiae to intestinal epithelium in tilapias Oreochromis sp.

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Barato, P; Martins, E R; Vasquez, G M; Ramirez, M; Melo-Cristino, J; Martínez, N; Iregui, C

2016-11-01

Streptococcosis caused by Streptococcus agalactiae is one of the most important diseases in the tilapia aquaculture industry. The role of the capsule of Streptococcus agalactiae in adherence to fish surfaces has not been evaluated and the mechanism of capsular regulation during adhesion has not been described. The aim of this study was to evaluate the role of the capsule of S. agalactiae during adhesion to intestinal epithelium of tilapia (Oreochromis sp.) in an ex vivo infection model. We show that the capsule impairs the adhesion of bacteria to host intestinal epithelium. Wild type (WT) strain SaTiBe08-18 (S. agalactiae recovered from tilapia) had reduced adhesion (P S. agalactiae to tilapia intestine and that the acidic milieu could regulate adherence of encapsulated strains. We found GlcNAc on the surface of adherent Δcps but not over the capsule in WT. This difference could be explained by the GlcNAc composition of Lancefield group B antigen and the peptidoglycan in GBS (Group B Streptococcus) and also may be related with better exposure of glycosylated adhesins in unencapsulated fish GBS. Understanding capsular regulation during adhesion of S. agalactiae may provide new leads to find a successful anti-adherence therapy to prevent streptococcosis in tilapia. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Comparison of Streptococcus agalactiae Isolated from Fish and Bovine using Multilocus Sequence Typing

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ANGELA MARIANA LUSIASTUTI

2013-12-01

Full Text Available Multilocus sequence typing (MLST has greater utility for determining the recent ancestral lineage and the relatedness of individual strains. Group B streptococci (GBS is one of the major causes of subclinical mastitis of dairy cattle in several countries. GBS also sporadically causes epizootic infections in fish. The aim of this study was to compare the evolutionary lineage of fish and bovine isolates in relation to the S. agalactiae global population as a whole by comparing the MLST profiles. Twenty S. agalactiae isolates were obtained from dairy cattle and fish. PCR products were amplified with seven different oligonucleotide primer pairs designed from the NEM316 GBS genome sequence. Clone complexes demonstrated that bovine and fish isolates were separate populations. These findings lead us to conclude that fish S. agalactiae is not a zoonotic agent for bovine. MLST could help clarify the emergence of pathogenic clones and to decide whether the host acts as a reservoir for another pathogenic lineage.

Relevance of Peptide Uptake Systems to the Physiology and Virulence of Streptococcus agalactiae

OpenAIRE

Samen, Ulrike; Gottschalk, Birgit; Eikmanns, Bernhard J.; Reinscheid, Dieter J.

2004-01-01

Streptococcus agalactiae is a major cause of invasive infections in human newborns. To satisfy its growth requirements, S. agalactiae takes up 9 of the 20 proteinogenic amino acids from the environment. Defined S. agalactiae mutants in one or several of four putative peptide permease systems were constructed and tested for peptide uptake, growth in various media, and expression of virulence traits. Oligopeptide uptake by S. agalactiae was shown to be mediated by the ABC transporter OppA1-F, w...

Streptococcus agalactiae in the environment of bovine dairy herds--rewriting the textbooks?

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Jørgensen, H J; Nordstoga, A B; Sviland, S; Zadoks, R N; Sølverød, L; Kvitle, B; Mørk, T

2016-02-29

Many free-stall bovine dairy herds in Norway fail to eradicate Streptococcus agalactiae despite long-term control measures. In a longitudinal study of 4 free-stall herds with automatic milking systems (AMS), milk and extramammary sites were sampled 4 times with 1-2 month intervals. Composite milk, rectal- and vaginal swabs were collected from dairy cows; rectal swabs from heifers and young stock; rectal- and tonsillar swabs from calves; and environmental swabs from the AMS, the floors, cow beds, watering and feeding equipment. A cross sectional study of 37 herds was also conducted, with 1 visit for environmental sampling. Fifteen of the herds were known to be infected with S. agalactiae while the remaining 22 had not had evidence of S. agalactiae mastitis in the preceding 2 years. All samples were cultured for S. agalactiae, and selected isolates (n=54) from positive herds were genotyped by Multi Locus Sequence Typing (MLST). Results show that the bovine gastrointestinal tract and the dairy cow environment are reservoirs of S. agalactiae, and point to the existence of 2 transmission cycles; a contagious transmission cycle via the milking machine and an oro-fecal transmission cycle, with drinking water as the most likely vehicle for transmission. Ten sequence types were identified, and results suggest that strains differ in their ability to survive in the environment and transmit within dairy herds. Measures to eradicate S. agalactiae from bovine dairy herds should take into account the extra-mammary reservoirs and the potential for environmental transmission of this supposedly exclusively contagious pathogen. Copyright © 2016. Published by Elsevier B.V.

Endocytosis‒Mediated Invasion and Pathogenicity of Streptococcus agalactiae in Rat Cardiomyocyte (H9C2)

OpenAIRE

Pooja, Sharma; Pushpanathan, Muthuirulan; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash

2015-01-01

Streptococcus agalactiae infection causes high mortality in cardiovascular disease (CVD) patients, especially in case of setting prosthetic valve during cardiac surgery. However, the pathogenesis mechanism of S. agalactiae associate with CVD has not been well studied. Here, we have demonstrated the pathogenicity of S. agalactiae in rat cardiomyocytes (H9C2). Interestingly, both live and dead cells of S. agalactiae were uptaken by H9C2 cells. To further dissect the process of S. agalactiae int...

Severe infective endocarditis in a healthy adult due to Streptococcus agalactiae.

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Fujita, Hiroaki; Nakamura, Itaru; Tsukimori, Ayaka; Sato, Akihiro; Ohkusu, Kiyofumi; Matsumoto, Tetsuya

2015-09-01

A case of severe endocarditis, with complications of multiple infarction, meningitis, and ruptured mitral chordae tendineae, caused by Streptococcus agalactiae in a healthy man, is reported. Emergency cardiovascular surgery was performed on the day of admission. Infective endocarditis caused by S. agalactiae is very rare, particularly in a healthy adult. In addition, microbiological analysis revealed that S. agalactiae of sequence type (ST) 19, which belongs to serotype III, was present in the patient's vegetation, mitral valve, and blood culture. It was therefore concluded that the endocarditis was caused by ST19, which has been reported as a non-invasive type of S. agalactiae. This was an extremely rare case in which S. agalactiae of ST19 caused very severe endocarditis in an adult patient with no underlying disease. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prevalence of the colonization by Streptococcus agalactiae in pregnant women from a public health system in Santo Ângelo – RS

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Franciane Rios Senger

2016-01-01

Full Text Available ABSTRACT: Background and Objectives: Streptococcus agalactiae (GBS is part of the female genital tract microbiota, however, its clinical significance is related to infections in newborns and can cause severe cases of pneumonia, septicemia and meningitis. Thus, the aim of this study is to determine the prevalence of colonization by S. agalactiae in pregnant women and analyze the sensitivity profile of the isolated front of antimicrobials. Methods: Vaginal and anorectal samples of pregnant women over 30 weeks of gestation were collected from February to June 2013. The samples were stored in Stuart transport medium and then inoculated in Todd-Hewitt broth added gentamicin and acid nalidixic with subsequent subculture on blood agar plates. For identification were performed Gram test, catalase, CAMP and latex agglutination. Furthermore, the antimicrobial susceptibility tests and the test for the detection of resistance induced clindamycin in the samples resistant to erythromycin were conducted. They are also assessed, through interviews, demographic, socioeconomic and clinical and obstetric data. Results: It was observed colonization in 22.5% (18/80 of the pregnant women. The strains were sensitive to most of the antibiotics tested except erythromycin, showing a resistance of 22.2% (4/18 isolates. However, none of the samples erythromycin resistant had induced resistance to clindamycin. Conclusion: The high maternal colonization by S. agalactiae found emphasize the importance of isolation of this bacterium in late pregnancy, preventing the occurrence of neonatal infection. KEYWORDS: Streptococcus agalactiae. Pregnancy. Prevalence.

Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

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Deguo Wang

2015-05-01

Full Text Available Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

Development of Primer Sets for Loop-Mediated Isothermal Amplification that Enables Rapid and Specific Detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae.

Science.gov (United States)

Wang, Deguo; Liu, Yanhong

2015-05-26

Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three pathogens are not available. With the 16S rRNA gene and 16S-23S rRNA intergenic spacers as targets, four sets of LAMP primers were designed for identification and differentiation of S. dysgalactiae, S. uberis and S. agalactiae. The detection limit of all four LAMP primer sets were 0.1 pg DNA template per reaction, the LAMP method with 16S rRNA gene and 16S-23S rRNA intergenic spacers as the targets can differentiate the three pathogens, which is potentially useful in epidemiological studies.

Streptococcus agalactiae in pregnancies complicated by preterm prelabor rupture of membranes.

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Musilova, Ivana; Pliskova, Lenka; Kutova, Radka; Jacobsson, Bo; Paterova, Pavla; Kacerovsky, Marian

2016-01-01

The main aim of this study was to evaluate the presence of Streptococcus agalactiae (S. agalactiae) in the vagina and the amniotic fluid in pregnancies complicated by preterm prelabor rupture of membranes (PPROM). The next aim was to evaluate the incidence of S. agalactiae early onset sepsis in newborns from PPROM pregnancies, with respect to the presence of S. agalactiae in the vagina and the amniotic fluid. Singleton gestations with PPROM between 24 + 0 and 36 + 6 were included. A vaginal swab was obtained, and amniocentesis was performed at admission. The presence of S. agalactiae in the vagina and in the amniotic fluid was assessed by culture and by real-time polymerase chain reaction, respectively. In total, 336 women were included. The presence of S. agalactiae in the vaginal and amniotic fluid was found in 9% (31/336) and 1% (3/336) of women. One woman had S. agalactiae in the amniotic fluid but was negative for the presence of S. agalactiae in the vaginal fluid. Early onset neonatal sepsis developed in one newborn from pregnancies complicated by the presence of S. agalactiae in the amniotic fluid. The presence of S. agalactiae in the vagina and amniotic fluid complicated approximately each 10th and each 100th PPROM pregnancy. Cultivation-negative findings of S. agalactiae in the vagina did not exclude the positivity of the amniotic fluid for S. agalactiae and the development of early onset sepsis in newborns.

Macrolide resistance gene erm(TR) and erm(TR)-carrying genetic elements in Streptococcus agalactiae: characterization of ICESagTR7, a new composite element containing IMESp2907.

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Mingoia, Marina; Morici, Eleonora; Marini, Emanuela; Brenciani, Andrea; Giovanetti, Eleonora; Varaldo, Pietro E

2016-03-01

The objective of this study was to investigate macrolide-resistant Streptococcus agalactiae isolates harbouring erm(TR), an erm(A) gene subclass, with emphasis on their erm(TR)-carrying genetic elements. Four erm(TR)-carrying elements have been described to date: three closely related (ICE10750-RD.2, Tn1806 and ICESp1108) in Streptococcus pyogenes, Streptococcus pneumoniae and S. pyogenes, respectively; and one completely different (IMESp2907, embedded in ICESp2906 to form ICESp2905) in S. pyogenes. Seventeen macrolide-resistant erm(TR)-positive S. agalactiae isolates were phenotypically and genotypically characterized. Their erm(TR)-carrying elements were explored by analysing the distinctive recombination genes of known erm(TR)-carrying integrative and conjugative elements (ICEs) and by PCR mapping. The new genetic context and organization of IMESp2907 in S. agalactiae were explored using several experimental procedures and in silico analyses. Five isolates harboured ICE10750-RD.2/Tn1806, five isolates harboured ICESp1108 and five isolates bore unknown erm(TR)-carrying elements. The remaining two isolates, exhibiting identical serotypes and pulsotypes, harboured IMESp2907 in a new genetic environment, which was further investigated in one of the two isolates, SagTR7. IMESp2907 was circularizable in S. agalactiae, as described in S. pyogenes. The new IMESp2907 junctions were identified based on its site-specific integration; the att sites were almost identical to those in S. pyogenes. In strain SagTR7, erm(TR)-carrying IMESp2907 was embedded in an erm(TR)-less internal element related to ICE10750-RD.2/Tn1806, which, in turn, was embedded in an ICESde3396-like element. The resulting whole ICE, ICESagTR7 (∼129 kb), was integrated into the chromosome downstream of the rplL gene, and was excisable in circular form and transferable by conjugation. This is the first study exploring erm(TR)-carrying genetic elements in S. agalactiae. © The Author 2015. Published by

In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

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Juliana Rosa da Silva

2017-08-01

Full Text Available Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%, tetO in 23 (19.5%, and tetM in 24 (20.3%. The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%, tetracycline (35.6%, gentamicin (9.3%, clindamycin (20.3%, penicillin (3.4%, and amikacin (38.1%; conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health.

Identification of a virulence-related surface protein XF in piscine Streptococcus agalactiae by pre-absorbed immunoproteomics.

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Liu, Guangjin; Zhang, Wei; Liu, Yongjie; Yao, Huochun; Lu, Chengping; Xu, Pao

2014-10-26

Since 2009, large-scale Streptococcus agalactiae infections have broken out in cultured tilapia farms in China, resulting in considerable economic losses. Screening of the surface proteins is required to identify virulence factors or protective antigens involved in piscine S.agalactiae infections in tilapia. Pre-absorbed immunoproteomics method (PAIM) is a useful method previously established in our laboratory for identifying bacterial surface proteins. A serine-rich repeat protein family 1 (Srr-1), designated XF, was identified by PAIM in piscine S. agalactiae isolate GD201008-001. To investigate the role of XF in the pathogenesis of piscine S. agalactiae, an isogenic xf mutant strain (Δxf) and a complemented strain (CΔxf) were successfully constructed. The Δxf mutant and CΔxf showed no significant differences in growth characteristics and adherence to HEp-2 cells compared with the wild-type strain. However the 50% lethal dose of Δxf was increased (4-fold) compared with that of the parental strain in a zebrafish infection model. The findings demonstrated that XF is a virulence-related, highly immunoreactive surface protein and is involved in the pathogenicity of S. agalactiae infections in fish.

Streptococcus agalactiae: HASTA AHORA EL ÚNICO Streptococcus PATÓGENO DE TILAPIAS CULTIVADAS EN COLOMBIA

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AP Jiménez

2007-01-01

Full Text Available Las estreptococosis son un conjunto de enfermedades ocasionadas por un grupo de cocos Gram positivos con similares signologías que involucran distintos órganos en los individuos afectados. La identiÀcación precisa de cada uno de estos microorganismos no se logra de manera deÀnitiva por los métodos tradicionales microbiológicos, por lo que se debe acudir a otro tipo de metodologías como las técnicas de biología molecular. En 1999 se identiÀcó por primera vez en Colombia la estreptococosis en híbridos de tilapias de cultivo. La pos-terior secuenciación del ADN de distintos aislamientos obtenidos de varias regiones del país demostró un 98,8% de aÀnidad con el Streptococcus agalactiae. El presente estudio pretende deÀnir si hasta la fecha existe solo esta especie de Streptococcus en el país causan-do infección o enfermedad en tilapias de cultivo o, por el contrario, son varias las especies que intervienen en los cuadros infecciosos. Se evaluaron aislamientos de tejidos, de agua y fango de los sitios de cultivo, así como de lugares de expendio de tilapia roja (Oreochromissp., utilizando técnicas microbiológicas, inmunoperoxidasa indirecta (IPI y PCR, espe-cíÀcas para el aislamiento e identiÀcación del S. agalactiae. Los resultados del presente estudio demostraron que hasta la fecha en el país únicamente se ha identiÀcado la especie S. agalactiae causando infección o enfermedad en tilapias. No tenemos evidencia de que otros Streptococcus reportados internacionalmente como S. iniae y otros Gram positivos causen estreptococosis en Colombia.La tilapia parece ser el principal reservorio del S. agalactiae en el país, y el riesgo zoonótico, aunque existe, es mínimo si se toman las medidas apropia-das de bioseguridad.

Distribution of serotypes and evaluation of antimicrobial susceptibility among human and bovine Streptococcus agalactiae strains isolated in Brazil between 1980 and 2006

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Tatiana Castro Abreu Pinto

Full Text Available Streptococcus agalactiae is a common agent of clinical and subclinical bovine mastitis and an important cause of human infections, mainly among pregnant women, neonates and nonpregnant adults with underlying diseases. The present study describes the genetic and phenotypic diversity among 392 S. agalactiae human and bovine strains isolated between 1980 and 2006 in Brazil. The most prevalent serotypes were Ia, II, III and V and all the strains were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampicin and tetracycline was observed. Among the erythromycin resistant strains, mefA/E, ermA and, mainly, ermB gene were detected, and a shift of prevalence from the macrolide resistance phenotype to the macrolidelincosamide- streptogramin B resistance phenotype over the years was observed. The 23 macrolide-resistant strains showed 19 different pulsed-field gel electrophoresis profiles. Regarding macrolide resistance, a major concern in S. agalactiae epidemiology, the present study describes an increase in erythromycin resistance from the 80s to the 90s followed by a decrease in the 2000-2006 period. Also, the genetic heterogeneity described points out that erythromycin resistance in Brazil is rather due to horizontal gene transmission than to spreading of specific macrolide-resistant clones.

Genomic comparison of virulent and non-virulent Streptococcus agalactiae in fish.

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Delannoy, C M J; Zadoks, R N; Crumlish, M; Rodgers, D; Lainson, F A; Ferguson, H W; Turnbull, J; Fontaine, M C

2016-01-01

Streptococcus agalactiae infections in fish are predominantly caused by beta-haemolytic strains of clonal complex (CC) 7, notably its namesake sequence type (ST) 7, or by non-haemolytic strains of CC552, including the globally distributed ST260. In contrast, CC23, including its namesake ST23, has been associated with a wide homeothermic and poikilothermic host range, but never with fish. The aim of this study was to determine whether ST23 is virulent in fish and to identify genomic markers of fish adaptation of S. agalactiae. Intraperitoneal challenge of Nile tilapia, Oreochromis niloticus (Linnaeus), showed that ST260 is lethal at doses down to 10(2) cfu per fish, whereas ST23 does not cause disease at 10(7) cfu per fish. Comparison of the genome sequence of ST260 and ST23 with those of strains derived from fish, cattle and humans revealed the presence of genomic elements that are unique to subpopulations of S. agalactiae that have the ability to infect fish (CC7 and CC552). These loci occurred in clusters exhibiting typical signatures of mobile genetic elements. PCR-based screening of a collection of isolates from multiple host species confirmed the association of selected genes with fish-derived strains. Several fish-associated genes encode proteins that potentially provide fitness in the aquatic environment. © 2014 John Wiley & Sons Ltd.

Development of a colloidal gold immunochromatographic strip for rapid detection of Streptococcus agalactiae in tilapia.

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Wen-de, Wu; Min, Li; Ming, Chen; Li-Ping, Li; Rui, Wang; Hai-Lan, Chen; Fu-Yan, Chen; Qiang, Mi; Wan-Wen, Liang; Han-Zhong, Chen

2017-05-15

A colloidal gold immunochromatographic strip was developed for rapid detection of Streptococcus agalactiae (S. agalactiae) infection in tilapia. The monoclonal antibodies (mAb) 4C12 and 3A9 were used to target S. agalactiae as colloidal gold-mAb conjugate and captured antibody, respectively. The colloidal gold immunochromatographic strip was assembled via routine procedures. Optimal pH and minimum antibody levels in the reaction system for gold colloidal-mAb 4C12 conjugation were pH 7.4 and 18μg/mL, respectively. Optimal concentrations of the captured antibody 3A9 and goat anti-mouse antibody were 0.6mg/mL and 2mg/mL, respectively. The sensitivity of the strip for detecting S. agalactiae was 1.5×10 5 colony forming units (CFU). No cross-reaction was observed with other commonly encountered bacteria, including Pseudomonas fluorescens, Aeromonas hydrophila, Vibrio anguillarum and Streptococcus iniae. The assay time for S. agalactiae was less than 15min. Tilapia samples artificially infected with S. agalactiae were tested using the newly developed strip. The results indicated that blood, brain, kidney, spleen, metanephros and intestine specimens of infected fish can be used for S. agalactiae detection. The validity of the strip was maintained for 6 months at 4°C. These findings suggested that the immunochromatographic strip was effective for spot and rapid detection of S. agalactiae infected tilapia. Copyright © 2016 Elsevier B.V. All rights reserved.

Population structure and virulence gene profiles of Streptococcus agalactiae collected from different hosts worldwide.

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Morach, Marina; Stephan, Roger; Schmitt, Sarah; Ewers, Christa; Zschöck, Michael; Reyes-Velez, Julian; Gilli, Urs; Del Pilar Crespo-Ortiz, María; Crumlish, Margaret; Gunturu, Revathi; Daubenberger, Claudia A; Ip, Margaret; Regli, Walter; Johler, Sophia

2018-03-01

Streptococcus agalactiae is a leading cause of morbidity and mortality among neonates and causes severe infections in pregnant women and nonpregnant predisposed adults, in addition to various animal species worldwide. Still, information on the population structure of S. agalactiae and the geographical distribution of different clones is limited. Further data are urgently needed to identify particularly successful clones and obtain insights into possible routes of transmission within one host species and across species borders. We aimed to determine the population structure and virulence gene profiles of S. agalactiae strains from a diverse set of sources and geographical origins. To this end, 373 S. agalactiae isolates obtained from humans and animals from five different continents were typed by DNA microarray profiling. A total of 242 different S. agalactiae strains were identified and further analyzed. Particularly successful clonal lineages, hybridization patterns, and strains were identified that were spread across different continents and/or were present in more than one host species. In particular, several strains were detected in both humans and cattle, and several canine strains were also detected in samples from human, bovine, and porcine hosts. The findings of our study suggest that although S. agalactiae is well adapted to various hosts including humans, cattle, dogs, rodents, and fish, interspecies transmission is possible and occurs between humans and cows, dogs, and rabbits. The virulence and resistance gene profiles presented enable new insights into interspecies transmission and make a crucial contribution to the identification of suitable targets for therapeutic agents and vaccines.

Assignment of Streptococcus agalactiae isolates to clonal complexes using a small set of single nucleotide polymorphisms

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Gilbert Gwendolyn L

2008-08-01

Full Text Available Abstract Background Streptococcus agalactiae (Group B Streptococcus (GBS is an important human pathogen, particularly of newborns. Emerging evidence for a relationship between genotype and virulence has accentuated the need for efficient and well-defined typing methods. The objective of this study was to develop a single nucleotide polymorphism (SNP based method for assigning GBS isolates to multilocus sequence typing (MLST-defined clonal complexes. Results It was found that a SNP set derived from the MLST database on the basis of maximisation of Simpsons Index of Diversity provided poor resolution and did not define groups concordant with the population structure as defined by eBURST analysis of the MLST database. This was interpreted as being a consequence of low diversity and high frequency horizontal gene transfer. Accordingly, a different approach to SNP identification was developed. This entailed use of the "Not-N" bioinformatic algorithm that identifies SNPs diagnostic for groups of known sequence variants, together with an empirical process of SNP testing. This yielded a four member SNP set that divides GBS into 10 groups that are concordant with the population structure. A fifth SNP was identified that increased the sensitivity for the clinically significant clonal complex 17 to 100%. Kinetic PCR methods for the interrogation of these SNPs were developed, and used to genotype 116 well characterized isolates. Conclusion A five SNP method for dividing GBS into biologically valid groups has been developed. These SNPs are ideal for high throughput surveillance activities, and combining with more rapidly evolving loci when additional resolution is required.

Assignment of Streptococcus agalactiae isolates to clonal complexes using a small set of single nucleotide polymorphisms.

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Honsa, Erin; Fricke, Thomas; Stephens, Alex J; Ko, Danny; Kong, Fanrong; Gilbert, Gwendolyn L; Huygens, Flavia; Giffard, Philip M

2008-08-19

Streptococcus agalactiae (Group B Streptococcus (GBS)) is an important human pathogen, particularly of newborns. Emerging evidence for a relationship between genotype and virulence has accentuated the need for efficient and well-defined typing methods. The objective of this study was to develop a single nucleotide polymorphism (SNP) based method for assigning GBS isolates to multilocus sequence typing (MLST)-defined clonal complexes. It was found that a SNP set derived from the MLST database on the basis of maximization of Simpsons Index of Diversity provided poor resolution and did not define groups concordant with the population structure as defined by eBURST analysis of the MLST database. This was interpreted as being a consequence of low diversity and high frequency horizontal gene transfer. Accordingly, a different approach to SNP identification was developed. This entailed use of the "Not-N" bioinformatic algorithm that identifies SNPs diagnostic for groups of known sequence variants, together with an empirical process of SNP testing. This yielded a four member SNP set that divides GBS into 10 groups that are concordant with the population structure. A fifth SNP was identified that increased the sensitivity for the clinically significant clonal complex 17 to 100%. Kinetic PCR methods for the interrogation of these SNPs were developed, and used to genotype 116 well characterized isolates. A five SNP method for dividing GBS into biologically valid groups has been developed. These SNPs are ideal for high throughput surveillance activities, and combining with more rapidly evolving loci when additional resolution is required.

Comparative proteome analysis of two Streptococcus agalactiae strains from cultured tilapia with different virulence.

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Li, Wei; Su, You-Lu; Mai, Yong-Zhan; Li, Yan-Wei; Mo, Ze-Quan; Li, An-Xing

2014-05-14

Streptococcus agalactiae is a major piscine pathogen, which causes significant morbidity and mortality among numerous fish species, and results in huge economic losses to aquaculture. Many S. agalactiae strains showing different virulence characteristics have been isolated from infected tilapia in different geographical regions throughout South China in the recent years, including natural attenuated S. agalactiae strain TFJ0901 and virulent S. agalactiae strain THN0901. In the present study, survival of tilapia challenged with S. agalactiae strain TFJ0901 and THN0901 (10(7)CFU/fish) were 93.3% and 13.3%, respectively. Moreover, there are severe lesions of the examined tissues in tilapia infected with strain THN0901, but no significant histopathological changes were observed in tilapia infected with the strain TFJ0901. In order to elucidate the factors responsible for the invasive potential of S. agalactiae between two strains TFJ0901 and THN0901, a comparative proteome analysis was applied to identify the different protein expression profiles between the two strains. 506 and 508 cellular protein spots of S. agalactiae TFJ0901 and THN0901 were separated by two dimensional electrophoresis, respectively. And 34 strain-specific spots, corresponding to 27 proteins, were identified successfully by MALDI-TOF mass spectrometry. Among them, 23 proteins presented exclusively in S. agalactiae TFJ0901 or THN0901, and the other 4 proteins presented in different isomeric forms between TFJ0901 and THN0901. Most of the strain-specific proteins were just involved in metabolic pathways, while 7 of them were presumed to be responsible for the virulence differences of S. agalactiae strain TFJ0901 and THN0901, including molecular chaperone DnaJ, dihydrolipoamide dehydrogenase, thioredoxin, manganese-dependent inorganic pyrophosphatase, elongation factor Tu, bleomycin resistance protein and cell division protein DivIVA. These virulence-associated proteins may contribute to identify new

Serine-Rich Repeat Proteins and Pili Promote Streptococcus agalactiae Colonization of the Vaginal Tract

NARCIS (Netherlands)

Sheen, Tamsin R.; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M.; Doran, Kelly S.

2011-01-01

Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal

Natural outbreak of Streptococcus agalactiae (GBS) infection in wild giant Queensland grouper, Epinephelus lanceolatus (Bloch), and other wild fish in northern Queensland, Australia.

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Bowater, R O; Forbes-Faulkner, J; Anderson, I G; Condon, K; Robinson, B; Kong, F; Gilbert, G L; Reynolds, A; Hyland, S; McPherson, G; Brien, J O'; Blyde, D

2012-03-01

Ninety-three giant Queensland grouper, Epinephelus lanceolatus (Bloch), were found dead in Queensland, Australia, from 2007 to 2011. Most dead fish occurred in northern Queensland, with a peak of mortalities in Cairns in June 2008. In 2009, sick wild fish including giant sea catfish, Arius thalassinus (Rüppell), and javelin grunter, Pomadasys kaakan (Cuvier), also occurred in Cairns. In 2009 and 2010, two disease epizootics involving wild stingrays occurred at Sea World marine aquarium. Necropsy, histopathology, bacteriology and PCR determined that the cause of deaths of 12 giant Queensland grouper, three wild fish, six estuary rays, Dasyatis fluviorum (Ogilby), one mangrove whipray, Himantura granulata (Macleay), and one eastern shovelnose ray, Aptychotrema rostrata (Shaw), was Streptococcus agalactiae septicaemia. Biochemical testing of 34 S. agalactiae isolates from giant Queensland grouper, wild fish and stingrays showed all had identical biochemical profiles. The 16S rRNA gene sequences of isolates confirmed all isolates were S. agalactiae; genotyping of selected S. agalactiae isolates showed the isolates from giant Queensland grouper were serotype Ib, whereas isolates from wild fish and stingrays closely resembled serotype II. This is the first report of S. agalactiae from wild giant Queensland grouper and other wild tropical fish and stingray species in Queensland, Australia. © 2012 Blackwell Publishing Ltd and State of Queensland.

Spring forward with improved Nile tilapia Oreochromis niloticus resistant to Streptococcus iniae and Streptococcus agalactiae IB

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Tilapia aquaculture worldwide is valued around US $ 7 billion. Tilapia are an important source of protein for domestic (top 5 most consumed seafoods) and global food security. Two gram postitive bacteria, Streptococcus iniae and S. agalactiae, are responsible for billion dollar losses annually. Gen...

Streptococcus agalactiae vaginitis: nonhemolytic variant on the Liofilchem® Chromatic StreptoB.

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Savini, Vincenzo; Marrollo, Roberta; D'Antonio, Marianna; D'Amario, Claudio; Fazii, Paolo; D'Antonio, Domenico

2013-01-01

Streptococcus agalactiae (group B Streptococcus, GBS) vaginal pathogenicity is not uniformly acknowledged throughout the literature; accordingly, in women, genital itching and burning, along with leukorrhea are commonly and almost exclusively referred to bacterial vaginosis, candidiasis and trichomoniasis. Conversely, GBS virulence for vagina was recognized in the past, as the organism has been observed to potentially cause local inflammation and discharge, as well as lactobacilli rarefaction. We depict here a case where a nonhemolytic (γ-hemolytic) GBS strain was found to be the etiologic agent of vaginal infection. Such uncommon S. agalactiae phenotypes are hard to be recognized and may be therefore responsible for misdiagnosing and underestimation of GBS vaginitis prevalence; here, we had the support of the Liofilchem(®) Chromatic StreptoB medium, that successfully detected such an atypical variant.

Streptococcus agalactiae vaginitis: nonhemolytic variant on the Liofilchem® Chromatic StreptoB

OpenAIRE

Savini, Vincenzo; Marrollo, Roberta; D’Antonio, Marianna; D’Amario, Claudio; Fazii, Paolo; D’Antonio, Domenico

2013-01-01

Streptococcus agalactiae (group B Streptococcus, GBS) vaginal pathogenicity is not uniformly acknowledged throughout the literature; accordingly, in women, genital itching and burning, along with leukorrhea are commonly and almost exclusively referred to bacterial vaginosis, candidiasis and trichomoniasis. Conversely, GBS virulence for vagina was recognized in the past, as the organism has been observed to potentially cause local inflammation and discharge, as well as lactobacilli rarefaction...

Molecular identification and histopathological study of natural Streptococcus agalactiae infection in hybrid tilapia (Oreochromis niloticus).

Science.gov (United States)

Laith, A A; Ambak, Mohd Azmi; Hassan, Marina; Sheriff, Shahreza Md; Nadirah, Musa; Draman, Ahmad Shuhaimi; Wahab, Wahidah; Ibrahim, Wan Nurhafizah Wan; Aznan, Alia Syafiqah; Jabar, Amina; Najiah, Musa

2017-01-01

The main objective of this study was to emphasize on histopathological examinations and molecular identification of Streptococcus agalactiae isolated from natural infections in hybrid tilapia ( Oreochromis niloticus ) in Temerloh Pahang, Malaysia, as well as to determine the susceptibility of the pathogen strains to various currently available antimicrobial agents. The diseased fishes were observed for variable clinical signs including fin hemorrhages, alterations in behavior associated with erratic swimming, exophthalmia, and mortality. Tissue samples from the eyes, brain, kidney, liver, and spleen were taken for bacterial isolation. Identification of S. agalactiae was screened by biochemical methods and confirmed by VITEK 2 and 16S rRNA gene sequencing. The antibiogram profiling of the isolate was tested against 18 standard antibiotics included nitrofurantoin, flumequine, florfenicol, amoxylin, doxycycline, oleandomycin, tetracycline, ampicillin, lincomycin, colistin sulfate, oxolinic acid, novobiocin, spiramycin, erythromycin, fosfomycin, neomycin, gentamycin, and polymyxin B. The histopathological analysis of eyes, brain, liver, kidney, and spleen was observed for abnormalities related to S. agalactiae infection. The suspected colonies of S. agalactiae identified by biochemical methods was observed as Gram-positive chained cocci, β-hemolytic, and non-motile. The isolate was confirmed as S. agalactiae by VITEK 2 (99% similarity), reconfirmed by 16S rRNA gene sequencing (99% similarity) and deposited in GenBank with accession no. KT869025. The isolate was observed to be resistance to neomycin and gentamicin. The most consistent gross findings were marked hemorrhages, erosions of caudal fin, and exophthalmos. Microscopic examination confirmed the presence of marked congestion and infiltration of inflammatory cell in the eye, brain, kidney, liver, and spleen. Eye samples showed damage of the lens capsule, hyperemic and hemorrhagic choroid tissue, and retina

Molecular identification and histopathological study of natural Streptococcus agalactiae infection in hybrid tilapia (Oreochromis niloticus

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Laith Abdul Razzak

2017-01-01

Full Text Available Aim: The main objective of this study was to emphasize on histopathological examinations and molecular identification of Streptococcus agalactiae isolated from natural infections in hybrid tilapia (Oreochromis niloticus in Temerloh Pahang, Malaysia, as well as to determine the susceptibility of the pathogen strains to various currently available antimicrobial agents. Materials and Methods: The diseased fishes were observed for variable clinical signs including fin hemorrhages, alterations in behavior associated with erratic swimming, exophthalmia, and mortality. Tissue samples from the eyes, brain, kidney, liver, and spleen were taken for bacterial isolation. Identification of S. agalactiae was screened by biochemical methods and confirmed by VITEK 2 and 16S rRNA gene sequencing. The antibiogram profiling of the isolate was tested against 18 standard antibiotics included nitrofurantoin, flumequine, florfenicol, amoxylin, doxycycline, oleandomycin, tetracycline, ampicillin, lincomycin, colistin sulfate, oxolinic acid, novobiocin, spiramycin, erythromycin, fosfomycin, neomycin, gentamycin, and polymyxin B. The histopathological analysis of eyes, brain, liver, kidney, and spleen was observed for abnormalities related to S. agalactiae infection. Results: The suspected colonies of S. agalactiae identified by biochemical methods was observed as Gram-positive chained cocci, β-hemolytic, and non-motile. The isolate was confirmed as S. agalactiae by VITEK 2 (99% similarity, reconfirmed by 16S rRNA gene sequencing (99% similarity and deposited in GenBank with accession no. KT869025. The isolate was observed to be resistance to neomycin and gentamicin. The most consistent gross findings were marked hemorrhages, erosions of caudal fin, and exophthalmos. Microscopic examination confirmed the presence of marked congestion and infiltration of inflammatory cell in the eye, brain, kidney, liver, and spleen. Eye samples showed damage of the lens capsule

Presence and resistance of Streptococcus agalactiae in vaginal specimens of pregnant and adult non-pregnant women and association with other aerobic bacteria.

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Numanović, Fatima; Smajlović, Jasmina; Gegić, Merima; Delibegović, Zineta; Bektaš, Sabaheta; Halilović, Emir; Nurkić, Jasmina

2017-02-01

Aim To determine the prevalence rate and resistance profile of Streptococcus agalactiae (S. agalactiae) in vaginal swabs of pregnant and adult non-pregnant women in the Tuzla region, Bosnia and Herzegovina (B&H), as well as its association with other aerobic bacteria. Methods This prospective study included 200 women, 100 pregnant and 100 adult non-pregnant. The research was conducted at the Institute of Microbiology, University Clinical Center Tuzla from October to December 2015. Standard aerobic microbiological techniques were used for isolation and identification of S. agalactiae and other aerobic bacteria. Antimicrobial susceptibility was determined by the disk diffusion and microdilution method(VITEK 2/AES instrument). Results Among 200 vaginal swabs, 17 (8.50%) were positive for S. agalactiae, e. g., 7% (7/100) of pregnant and 10% (10/100) of adult non-pregnant women. In the pregnant group, 71.4% (5/7) of S. agalactiae isolates were susceptible to clindamycin and 85.7%(6/7) to erythromycin. In the adult non-pregnant group, only resistance to clindamycin was observed in one patient (1/10; 10%). S. agalactiae as single pathogen was isolated in 57.14% (4/7) of pregnant and 60% (6/10) of adult non-pregnant S. agalactiae positive women. In mixed microbial cultures S. agalactiae was most frequently associated with Enterococcus faecalis and Escherichia coli. Conclusion The rate of S. agalactiae positive women in the population of pregnant and adult non-pregnant women of Tuzla Canton, B&H is comparable with other European countries. Large studies are needed to develop a common national strategy for the prevention of S. agalactiae infection in B&H, especially during pregnancy. Copyright© by the Medical Assotiation of Zenica-Doboj Canton.

GC-MS-Based Metabolome and Metabolite Regulation in Serum-Resistant Streptococcus agalactiae.

Science.gov (United States)

Wang, Zhe; Li, Min-Yi; Peng, Bo; Cheng, Zhi-Xue; Li, Hui; Peng, Xuan-Xian

2016-07-01

Streptococcus agalactiae causes severe systemic infections in human and fish. In the present study, we established a pathogen-plasma interaction model by which we explored how S. agalactiae evaded serum-mediated killing. We found that S. agalactiae grew faster in the presence of yellow grouper plasma than in the absence of the plasma, indicating S. agalactiae evolved a way of evading the fish immune system. To determine the events underlying this phenotype, we applied GC-MS-based metabolomics approaches to identify differential metabolomes between S. agalactiae cultured with and without yellow grouper plasma. Through bioinformatics analysis, decreased malic acid and increased adenosine were identified as the most crucial metabolites that distinguish the two groups. Meanwhile, they presented with decreased TCA cycle and elevated purine metabolism, respectively. Finally, exogenous malic acid and adenosine were used to reprogram the plasma-resistant metabolome, leading to elevated and decreased susceptibility to the plasma, respectively. Therefore, our findings reveal for the first time that S. agalactiae utilizes a metabolic trick to respond to plasma killing as a result of serum resistance, which may be reverted or enhanced by exogenous malic acid and adenosine, respectively, suggesting that the metabolic trick can be regulated by metabolites.

Capsular typing of Streptococcus agalactiae (Lancefield group B streptococci) from fish using multiplex PCR and serotyping

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Streptococcus spp. including Streptococcus agalactiae (Lancefield group B streptococci) are considered emerging pathogens responsible for approximately $1 billion USD in annual losses to the global tilapia (Oreochromis sp.) aquaculture industry. This study evaluated a published multiplex PCR capsul...

Inapparent Streptococcus agalactiae infection in adult/commercial tilapia.

Science.gov (United States)

Sun, Jiufeng; Fang, Wei; Ke, Bixia; He, Dongmei; Liang, Yuheng; Ning, Dan; Tan, Hailing; Peng, Hualin; Wang, Yunxin; Ma, Yazhou; Ke, Changwen; Deng, Xiaoling

2016-05-24

We report on inapparent infections in adult/commercial tilapia in major tilapia fish farms in Guangdong. A total of 146 suspected isolates were confirmed to be S. agalactiae using an API 20 Strep system and specific PCR amplification. All isolates were identified as serotype Ia using multiplex serotyping PCR. An MLST assay showed single alleles of adhP (10), atr (2), glcK (2), glnA (1), pheS (1), sdhA (3) and tkt (2), and this profile was designated 'unique ST 7'. The analysis of virulence genes resulted in 10 clusters, of which dltr-bca-sodA-spb1-cfb-bac (62, 42.47%) was the predominant virulence gene profile. The PFGE analysis of S. agalactiae yielded 6 distinct PFGE types (A, B, C, D, F and G), of which Pattern C (103) was the predominant type, accounting for approximately 70.55% (103/146) of the total S. agalactiae strains. Therefore, unlike what has been found in juvenile tilapia, in which PFGE pattern D/F is the major prevalent pattern, we found that pattern C was the major prevalent pattern in inapparent infected adult/commercial tilapia in Guangdong, China. In conclusion, we close a gap in the current understanding of S. agalactiae epidemiology and propose that researchers should be alert for inapparent S. agalactiae infections in adult/commercial tilapia to prevent a potential threat to food safety.

Streptococcus agalactiae endocarditis presenting as acalculous cholecystitis in a previously well woman.

LENUS (Irish Health Repository)

Brewer, Linda

2013-01-01

This case report describes the unusual presentation of a previously very well woman with Streptococcus agalactiae endocarditis in the emergency department. History, examination and preliminary laboratory and radiological investigations supported a diagnosis of acalculous cholecystitis, for which she was given intravenous broad spectrum antimicrobial therapy. One day following admission, the patient deteriorated and became unresponsive. Subsequent MRI of the brain revealed multiple bihemispheric cerebral emboli and a large, mobile mitral valve thrombus was visualised on her transoesophageal echocardiogram. S agalactiae was cultured from venous blood samples and her antimicrobial cover was adjusted accordingly. Despite her presumed guarded prognosis, this patient made a remarkable recovery. To our knowledge, the association of S agalactiae endocarditis with acalculous cholecystitis has not been previously described.

The protective duration of Streptococcus agalactiae vaccine in Nile Tilapia for the prevention of streptococcosis

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, Sukenda

2016-02-01

Full Text Available ABSTRACT The aim of this study was to assess the protective duration of Streptococcus agalactiae vaccine against streptococcosis in Nile tilapia. Fish were treated by the whole cell vaccine, ECP vaccine and mixture of whole cell and ECP vaccine. After 14, 28, 42, and 52 day post-vaccination (DPV, the fish were intraperitoneally challenged with 104  cfu/mL S. agalactiae. The results showed mortality rate of whole-cell vaccine (A, ECP vaccine (B and mix vaccine (C up to day 42 was significantly (P<0.05 lower than the control treatment, namely 73.33%; 80%; and 76%, respectively. The mortality rate of vaccine treatments A, B, and C on day 56 had no significant difference (P>0.05 with the control. The value of antibody titer vaccine treatments A, B, and C indicate that antigen-antibody reaction on day 28 after the vaccination was significantly (P <0.05 higher than the control that were 3.67; 3.33; and 3.67. Antigen-antibody reaction on day 42 after the vaccination was founded, but did not different significantly (P>0.05 with the control. Bacterial population in treatment A, B, and C in the organs of the fish until the 28th day was still under the control of 104  cfu/mL. S. agalactiae vaccine protection duration is 42 days after the vaccination. Keywords : nile tilapia, Streptococcus agalactiae, duration, vaccine, streptococcosis  ABSTRAK Penelitian ini bertujuan untuk menganalisis durasi proteksi dari vaksin Streptococcus agalactiae sebagai pencegahan terhadap streptococcosis pada ikan nila. Ikan divaksinasi dengan vaksin sel utuh, ECP dan gabungan sel utuh dan ECP dari S. agalactiae yang diinjeksi secara intrapetorineal. Ikan diuji tantang S. agalactiae 104  cfu/mL pada hari ke-14, ke-28, ke-42, dan ke-56 pascavaksinasi. Hasil penelitian menunjukkan tingkat mortalitas perlakuan vaksin sel utuh (A, vaksin ECP (B, dan gabungan vaksin sel utuh dengan ECP (C hingga hari ke-42 masih signifikan (P<0,05 lebih rendah dari perlakuan kontrol yaitu 73

Annual incidence, prevalence and transmission characteristics of Streptococcus agalactiae in Danish dairy herds

DEFF Research Database (Denmark)

Mweu, Marshal M.; Nielsen, Søren S.; Hisham Beshara Halasa, Tariq

2012-01-01

-level incidence rates and apparent prevalences of Streptococcus agalactiae (S. agalactiae) in the population of Danish dairy cattle herds over a 10-year period from 2000 to 2009 inclusive and (2) to estimate the herd-level entry and exit rates (demographic parameters), the transmission parameter, β, and recovery...... rate for S. agalactiae infection. Data covering the specified period, on bacteriological culture of all bulk tank milk samples collected annually as part of the mandatory Danish S. agalactiae surveillance scheme, were extracted from the Danish Cattle Database and subsequently analysed....... There was an increasing trend in both the incidence and prevalence of S. agalactiae over the study period. Per 100 herd-years the value of β was 54.1 (95% confidence interval [CI] 46.0–63.7); entry rate 0.3 (95% CI 0.2–0.4); infection-related exit rate 7.1 (95% CI 5.6–8.9); non-infection related exit rate 9.2 (95% CI 7...

TOKSISITAS PROTEIN 89 kDa PRODUK EKSTRASELULER Streptococcus agalactiae PADA IKAN NILA (Oreochromis niloticus

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Amrullah Amrullah

2015-09-01

Full Text Available Identifikasi protein toksin yang bersifat antigenik dari produk ekstraselular (ECP crude Streptococcus agalactiae penting dilakukan untuk pengembangan vaksin protein toksoid. Penelitian ini bertujuan untuk mengevaluasi toksisitas protein dengan berat molekul 89 kDa dari ECP Streptococcus agalactiae hasil fraksinasi dengan SDS-PAGE (ECPP89. Ikan nila dengan bobot sekitar 25 g masing-masing diinjeksi secara intraperitonial dengan protein ECPP89 dosis 1, 2, 4, 8, dan 16 μg/mL/ekor ikan (secara berturut-turut diberi kode ECPP89-1, ECPP89-2, ECPP89-4, ECPP89-8, dan ECPP89-16. Sebagai kontrol positif ikan diinjeksi dengan bakteri utuh S. agalactiae 1 x 104 cfu/mL (WCB dan ECP crude S. agalactiae (ECPC, sementara kontrol negatif ikan diinjeksi larutan PBS. Ikan dipelihara selama 15 hari dengan kepadatan 10 ekor (70 L air. Hasil penelitian menunjukkan bahwa ikan nila yang diinjeksi dengan ECPP89 mengalami gejala seperti perubahan morfologi, perubahan nafsu makan, dan perubahan renang ikan. Mortalitas pada perlakuan ECPP89 secara umum lebih tinggi dibandingkan dengan ECPC, namun lebih rendah (p<0,05 dibandingkan dengan WCB. Mortalitas ikan pada perlakuan ECPP89-4, ECPP89-8, dan ECPP89-16 tidak berbeda tetapi secara signifikan lebih tinggi dibandingkan dengan ECPC dan dua dosis perlakuan ECPP89 lainnya (p<0,05. Ikan kontrol negatif tidak mengalami kematian maupun perubahan klinis. Hasil ini menunjukkan bahwa ECPP89 merupakan protein toksin dari ECP S. agalactiae.

Identification of Streptococcus agalactiae by fluorescent in situ hybridization compared to culturing and the determination of prevalence of Streptococcus agalactiae colonization among pregnant women in Bushehr, Iran.

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Tajbakhsh, Saeed; Norouzi Esfahani, Marjan; Emaneini, Mohammad; Motamed, Niloofar; Rahmani, Elham; Gharibi, Somayyeh

2013-09-08

Pregnant women colonized by Streptococcus agalactiae (group B streptococci [GBS]) may transfer this microorganism to their newborns. S. agalactiae is an important cause of pneumonia, sepsis, and meningitis in newborns. Fluorescent in situ hybridization (FISH) is considered as a method of identification in the field of diagnostic microbiology. In this paper, we have designed a study to compare the DNA FISH after 7 h Lim broth enrichment and culturing for the identification of S. agalactiae and to determine the prevalence of vaginal colonization by S. agalactiae among pregnant women in Bushehr, Iran. Vaginal swab specimens were obtained from 285 pregnant women at 35 weeks or more than 35 weeks of gestation. The specimens were inoculated into Lim broth. In order to evaluate the sensitivity and specificity of GBS DNA FISH after 7 h Lim broth enrichment, the specimens were tested using both FISH and conventional culture methods. In addition, the prevalence of GBS colonization was determined. Based on the results of this study, both the sensitivity and specificity of FISH were 100%. S. agalactiae was detected by both culture and FISH in 27 of the 285 pregnant women. Thus, the prevalence of GBS colonization was 9.5%. Since short-term (7 h) Lim broth enrichment followed by FISH using oligonucleotide probes showed a high sensitivity and specificity, this protocol is therefore a highly accurate and relatively rapid method for the detection of S. agalactiae. Our analysis suggests that the use of DNA FISH to screen for S. agalactiae colonization in pregnant women may be considered in the absence of GBS culture availability.

Novel substrate specificity of glutathione synthesis enzymes from Streptococcus agalactiae and Clostridium acetobutylicum

International Nuclear Information System (INIS)

Kino, Kuniki; Kuratsu, Shoko; Noguchi, Atsushi; Kokubo, Masahiro; Nakazawa, Yuji; Arai, Toshinobu; Yagasaki, Makoto; Kirimura, Kohtaro

2007-01-01

Glutathione (GSH) is synthesized by γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GS) in living organisms. Recently, bifunctional fusion protein, termed γ-GCS-GS catalyzing both γ-GCS and GS reactions from gram-positive firmicutes Streptococcus agalactiae, has been reported. We revealed that in the γ-GCS activity, S. agalactiae γ-GCS-GS had different substrate specificities from those of Escherichia coli γ-GCS. Furthermore, S. agalactiae γ-GCS-GS synthesized several kinds of γ-glutamyltripeptide, γ-Glu-X aa -Gly, from free three amino acids. In Clostridium acetobutylicum, the genes encoding γ-GCS and putative GS were found to be immediately adjacent by BLAST search, and had amino acid sequence homology with S. agalactiae γ-GCS-GS, respectively. We confirmed that the proteins expressed from each gene showed γ-GCS and GS activity, respectively. C. acetobutylicum GS had broad substrate specificities and synthesized several kinds of γ-glutamyltripeptide, γ-Glu-Cys-X aa . Whereas the substrate specificities of γ-GCS domain protein and GS domain protein of S. agalactiae γ-GCS-GS were the same as those of S. agalactiae γ-GCS-GS

In vitro antimicrobial activity of Combretum molle (Combretaceae) against Staphylococcus aureus and Streptococcus agalactiae isolated from crossbred dairy cows with clinical mastitis.

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Regassa, Fekadu; Araya, Mengistu

2012-08-01

Following the rapidly expanding dairy enterprise, mastitis has remained the most economically damaging disease. The objective of this study was mainly to investigate the in vitro antibacterial activities of ethanol extracts of Combretum molle (R.Br.Ex.G.Don) Engl & Diels (Combretaceae) against antibiotic-resistant and susceptible Staphylococcus aureus and Streptococcus agalactiae isolated from clinical cases of bovine mastitis using agar disc diffusion method. The leaf and bark extracts showed antibacterial activity against S. aureus at concentrations of 3 mg/ml while the stem and seed extract did not show any bioactivity. Although both leaf and bark extracts were handled in the same manner, the antibacterial activity of the bark extract against the bacterial strains had declined gradually to a lower level as time advanced after extraction. The leaf extract had sustained bioactivity for longer duration. The susceptibility of the bacteria to the leaf extract is not obviously different between S. aureus and S. agalactiae. Also, there was no difference in susceptibility to the leaf extract between the antibiotic-resistant and antibiotic-sensitive bacteria. Further phytochemical and in vivo efficacy and safety studies are required to evaluate the therapeutic value of the plant against bovine mastitis.

Multiple Evolutionary Selections Involved in Synonymous Codon Usages in the Streptococcus agalactiae Genome.

Science.gov (United States)

Ma, Yan-Ping; Ke, Hao; Liang, Zhi-Ling; Liu, Zhen-Xing; Hao, Le; Ma, Jiang-Yao; Li, Yu-Gu

2016-02-24

Streptococcus agalactiae is an important human and animal pathogen. To better understand the genetic features and evolution of S. agalactiae, multiple factors influencing synonymous codon usage patterns in S. agalactiae were analyzed in this study. A- and U-ending rich codons were used in S. agalactiae function genes through the overall codon usage analysis, indicating that Adenine (A)/Thymine (T) compositional constraints might contribute an important role to the synonymous codon usage pattern. The GC3% against the effective number of codon (ENC) value suggested that translational selection was the important factor for codon bias in the microorganism. Principal component analysis (PCA) showed that (i) mutational pressure was the most important factor in shaping codon usage of all open reading frames (ORFs) in the S. agalactiae genome; (ii) strand specific mutational bias was not capable of influencing the codon usage bias in the leading and lagging strands; and (iii) gene length was not the important factor in synonymous codon usage pattern in this organism. Additionally, the high correlation between tRNA adaptation index (tAI) value and codon adaptation index (CAI), frequency of optimal codons (Fop) value, reinforced the role of natural selection for efficient translation in S. agalactiae. Comparison of synonymous codon usage pattern between S. agalactiae and susceptible hosts (human and tilapia) showed that synonymous codon usage of S. agalactiae was independent of the synonymous codon usage of susceptible hosts. The study of codon usage in S. agalactiae may provide evidence about the molecular evolution of the bacterium and a greater understanding of evolutionary relationships between S. agalactiae and its hosts.

Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.

Science.gov (United States)

Li, Wei; Wang, Hai-Qing; He, Run-Zhen; Li, Yan-Wei; Su, You-Lu; Li, An-Xing

2016-08-01

Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel

Single nucleotide resolution RNA-seq uncovers new regulatory mechanisms in the opportunistic pathogen Streptococcus agalactiae.

Science.gov (United States)

Rosinski-Chupin, Isabelle; Sauvage, Elisabeth; Sismeiro, Odile; Villain, Adrien; Da Cunha, Violette; Caliot, Marie-Elise; Dillies, Marie-Agnès; Trieu-Cuot, Patrick; Bouloc, Philippe; Lartigue, Marie-Frédérique; Glaser, Philippe

2015-05-30

Streptococcus agalactiae, or Group B Streptococcus, is a leading cause of neonatal infections and an increasing cause of infections in adults with underlying diseases. In an effort to reconstruct the transcriptional networks involved in S. agalactiae physiology and pathogenesis, we performed an extensive and robust characterization of its transcriptome through a combination of differential RNA-sequencing in eight different growth conditions or genetic backgrounds and strand-specific RNA-sequencing. Our study identified 1,210 transcription start sites (TSSs) and 655 transcript ends as well as 39 riboswitches and cis-regulatory regions, 39 cis-antisense non-coding RNAs and 47 small RNAs potentially acting in trans. Among these putative regulatory RNAs, ten were differentially expressed in response to an acid stress and two riboswitches sensed directly or indirectly the pH modification. Strikingly, 15% of the TSSs identified were associated with the incorporation of pseudo-templated nucleotides, showing that reiterative transcription is a pervasive process in S. agalactiae. In particular, 40% of the TSSs upstream genes involved in nucleotide metabolism show reiterative transcription potentially regulating gene expression, as exemplified for pyrG and thyA encoding the CTP synthase and the thymidylate synthase respectively. This comprehensive map of the transcriptome at the single nucleotide resolution led to the discovery of new regulatory mechanisms in S. agalactiae. It also provides the basis for in depth analyses of transcriptional networks in S. agalactiae and of the regulatory role of reiterative transcription following variations of intra-cellular nucleotide pools.

Expression, purification, crystallization and preliminary crystallographic analysis of laminin-binding protein (Lmb) from Streptococcus agalactiae

International Nuclear Information System (INIS)

Ragunathan, Preethi; Spellerberg, Barbara; Ponnuraj, Karthe

2009-01-01

Laminin-binding protein from S. agalactiae was expressed, purified and crystallized and X-ray diffraction data were collected to 2.5 Å resolution. Laminin-binding protein (Lmb), a surface-exposed lipoprotein from Streptococcus agalactiae (group B streptococcus), mediates attachment to human laminin and plays a crucial role in the adhesion/invasion of eukaryotic host cells. However, the structural basis of laminin binding still remains unclear. In the context of detailed structural analysis, the lmb gene has been cloned, expressed in Escherichia coli, purified and crystallized. The crystals diffracted to a resolution of 2.5 Å and belonged to the monoclinic space group P2 1 , with unit-cell parameters a = 56.63, b = 70.60, c = 75.37 Å, β = 96.77°

[Effect of the 10 kb sequence of piscine Streptococcus agalactiae on bacterial virulence].

Science.gov (United States)

Liu, Guangjin; Zhu, Jielian; Shi, Ziwei; Ding, Ming; Wang, Ruyi; Yao, Huochun; Lu, Chengping; Xu, Pao

2016-01-04

From the previous comparative genomic analysis, we found a specific unknown 10 kb sequence (including 11 Open reading Frames) in Chinese piscine strain GD201008-001 genome. To study the role of 10 kb in the pathogenicity of piscine S. agalactiae, the 10 kb sequence was deleted from the GD201008-001 genome. The isogenic mutant Δ10 kb was constructed by using the temperature-sensitive Streptococcus-E. coli shuttle vector pSET4s. We compared the growth characteristics, adherence to HEp-2 cell and bacterial virulence in a zebrafish infection model between wild strain and mutant. Meanwhile the expressions of the known virulence genes from GD201008-001 and Δ10 kb were also quantified by real-time PCR. The Δ10 kb showed no significant differences in bacterial morphology and adherence to HEp-2 cells compared with the wild-type strain, but the speed of growth was slightly slower than the wild strain. Furthermore the 50% lethal dose of Δ10 kb was decreased up to 10-fold (P kb sequence of piscine Streptococcus agalactiae exerts a significant effect on bacterial virulence and probably regulates the virulence genes expression of GD20 1008-001.

Identification of genes preferentially expressed by highly virulent piscine Streptococcus agalactiae upon interaction with macrophages.

Directory of Open Access Journals (Sweden)

Chang-Ming Guo

Full Text Available Streptococcus agalactiae, long recognized as a mammalian pathogen, is an emerging concern with regard to fish. In this study, we used a mouse model and in vitro cell infection to evaluate the pathogenetic characteristics of S. agalactiae GD201008-001, isolated from tilapia in China. This bacterium was found to be highly virulent and capable of inducing brain damage by migrating into the brain by crossing the blood-brain barrier (BBB. The phagocytosis assays indicated that this bacterium could be internalized by murine macrophages and survive intracellularly for more than 24 h, inducing injury to macrophages. Further, selective capture of transcribed sequences (SCOTS was used to investigate microbial gene expression associated with intracellular survival. This positive cDNA selection technique identified 60 distinct genes that could be characterized into 6 functional categories. More than 50% of the differentially expressed genes were involved in metabolic adaptation. Some genes have previously been described as associated with virulence in other bacteria, and four showed no significant similarities to any other previously described genes. This study constitutes the first step in further gene expression analyses that will lead to a better understanding of the molecular mechanisms used by S. agalactiae to survive in macrophages and to cross the BBB.

Identification of Genes Preferentially Expressed by Highly Virulent Piscine Streptococcus agalactiae upon Interaction with Macrophages

Science.gov (United States)

Guo, Chang-Ming; Chen, Rong-Rong; Kalhoro, Dildar Hussain; Wang, Zhao-Fei; Liu, Guang-Jin; Lu, Cheng-Ping; Liu, Yong-Jie

2014-01-01

Streptococcus agalactiae, long recognized as a mammalian pathogen, is an emerging concern with regard to fish. In this study, we used a mouse model and in vitro cell infection to evaluate the pathogenetic characteristics of S. agalactiae GD201008-001, isolated from tilapia in China. This bacterium was found to be highly virulent and capable of inducing brain damage by migrating into the brain by crossing the blood–brain barrier (BBB). The phagocytosis assays indicated that this bacterium could be internalized by murine macrophages and survive intracellularly for more than 24 h, inducing injury to macrophages. Further, selective capture of transcribed sequences (SCOTS) was used to investigate microbial gene expression associated with intracellular survival. This positive cDNA selection technique identified 60 distinct genes that could be characterized into 6 functional categories. More than 50% of the differentially expressed genes were involved in metabolic adaptation. Some genes have previously been described as associated with virulence in other bacteria, and four showed no significant similarities to any other previously described genes. This study constitutes the first step in further gene expression analyses that will lead to a better understanding of the molecular mechanisms used by S. agalactiae to survive in macrophages and to cross the BBB. PMID:24498419

Streptococcus agalactiae Inhibits Candida albicans Hyphal Development and Diminishes Host Vaginal Mucosal TH17 Response

OpenAIRE

Xiao-Yu Yu; Fei Fu; Wen-Na Kong; Qian-Kun Xuan; Dong-Hua Wen; Xiao-Qing Chen; Yong-Ming He; Li-Hua He; Jian Guo; Ai-Ping Zhou; Yang-Hong Xi; Li-Jun Ni; Yu-Feng Yao; Wen-Juan Wu

2018-01-01

Streptococcus agalactiae and Candida albicans often co-colonize the female genital tract, and under certain conditions induce mucosal inflammation. The role of the interaction between the two organisms in candidal vaginitis is not known. In this study, we found that co-infection with S. agalactiae significantly attenuated the hyphal development of C. albicans, and that EFG1-Hwp1 signal pathway of C. albicans was involved in this process. In a mouse model of vulvovaginal candidiasis (VVC), the...

Streptococcus agalactiae Inhibits Candida albicans Hyphal Development and Diminishes Host Vaginal Mucosal TH17 Response.

Science.gov (United States)

Yu, Xiao-Yu; Fu, Fei; Kong, Wen-Na; Xuan, Qian-Kun; Wen, Dong-Hua; Chen, Xiao-Qing; He, Yong-Ming; He, Li-Hua; Guo, Jian; Zhou, Ai-Ping; Xi, Yang-Hong; Ni, Li-Jun; Yao, Yu-Feng; Wu, Wen-Juan

2018-01-01

Streptococcus agalactiae and Candida albicans often co-colonize the female genital tract, and under certain conditions induce mucosal inflammation. The role of the interaction between the two organisms in candidal vaginitis is not known. In this study, we found that co-infection with S. agalactiae significantly attenuated the hyphal development of C. albicans , and that EFG1 -Hwp1 signal pathway of C. albicans was involved in this process. In a mouse model of vulvovaginal candidiasis (VVC), the fungal burden and the levels of pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α showed a increase on co-infection with S. agalactiae , while the level of TH17 T cells and IL-17 in the cervicovaginal lavage fluid were significantly decreased. Our results indicate that S. agalactiae inhibits C. albicans hyphal development by downregulating the expression of EFG1 -Hwp1. The interaction between S. agalactiae and C. albicans may attenuate host vaginal mucosal TH17 immunity and contribute to mucosal colonization by C. albicans .

Investigation of the translation-initiation factor IF2 gene, infB, as a tool to study the population structure of Streptococcus agalactiae

DEFF Research Database (Denmark)

Hedegaard, J; Hauge, M; Fage-Larsen, J

2000-01-01

The sequence of infB, encoding the prokaryotic translation-initiation factor 2 (IF2), was determined in eight strains of Streptococcus agalactiae (group B streptococcus) and an alignment revealed limited intraspecies diversity within S. agalactiae. The amino acid sequence of IF2 from S. agalactiae...... and from related species were aligned and revealed an interspecies conserved central and C-terminal part, and an N-terminal part that is highly variable in length and amino acid sequence. The diversity and relationships in a collection of 58 genetically distinct strains of S. agalactiae were evaluated...... by comparing a partial sequence of infB. A total of six alleles were detected for the region of infB analysed. The alleles correlated with the separation of the same strains of S. agalactiae into major evolutionary lineages, as shown in previous work. The partial sequences of infB were furthermore used...

Experimental early pathogenesis of Streptococcus agalactiae infection in red tilapia Oreochromis spp.

Science.gov (United States)

Iregui, C A; Comas, J; Vásquez, G M; Verján, N

2016-02-01

Streptococcus agalactiae causes a severe systemic disease in fish, and the routes of entry are still ill-defined. To address this issue, two groups of 33 red tilapia Oreochromis spp. each of 10 g were orally infected with S. agalactiae (n = 30), and by immersion (n = 30), six individuals were control-uninfected fish. Three tilapias were killed at each time point from 30 min to 96 h post-inoculation (pi); controls were killed at 96 h. Samples from most tissues were examined by haematoxylin-eosin (H&E), indirect immunoperoxidase (IPI) and periodic acid-Schiff; only intestine from fish infected by gavage was evaluated by transmission electron microscopy. The results of both experiments suggest that the main entry site of S. agalactiae in tilapia is the gastrointestinal epithelium; mucus seems to play an important defensive role, and environmental conditions may be an important predisposing factor for the infection. © 2015 John Wiley & Sons Ltd.

Complete genome sequence of an attenuated Sparfloxacin-resistant Streptococcus agalactiae strain 138spar

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The complete genome of a sparfloxacin-resistant Streptococcus agalactiae vaccine strain 138spar is 1,838,126 bp in size. The genome has 1892 coding sequences and 82 RNAs. The annotation of the genome is added by the NCBI Prokaryotic Genome Annotation Pipeline. The publishing of this genome will allo...

Molecular Characterization of Streptococcus agalactiae Isolates From Pregnant and Non-Pregnant Women at Yazd University Hospital, Iran.

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Sadeh, Maryam; Firouzi, Roya; Derakhshandeh, Abdollah; Bagher Khalili, Mohammad; Kong, Fanrong; Kudinha, Timothy

2016-02-01

Streptococcus agalactiae (Group B streptococcus, GBS) that colonize the vaginas of pregnant women may occasionally cause neonatal infections. It is one of the most common causes of sepsis and meningitis in neonates and of invasive diseases in pregnant women. It can also cause infectious disease among immunocompromised individuals. The distribution of capsular serotypes and genotypes varies over time and by geographic era. The serotyping and genotyping data of GBS in Iranian pregnant and non-pregnant women seems very limited. The aim of this study was to investigate the GBS ‎molecular capsular serotype ‎and genotype distribution of pregnant and non-pregnant carrier ‎women at Yazd university hospital, in Iran.‎. In this cross-sectional study, a total of 100 GBS strains isolated from 237 pregnant and 413 non-pregnant women were investigated for molecular capsular serotypes and surface protein genes using the multiplex PCR assay. The Chi-square method was used for statistical analysis. Out of 650 samples, 100 (15.4%) were identified as GBS, with a predominance of capsular serotypes III (50%) [III-1 (49), III-3 (1)], followed by II (25%), Ia (12%), V (11%), and Ib (2%), which was similar with another study conducted in Tehran, Iran, but they had no serotype Ia in their report. The surface protein antigen genes distribution was rib (53%), epsilon (38%), alp2/3 (6%), and alpha-c (3%). The determination of serotype and surface proteins of GBS strains distribution would ‎be ‎relevant ‎for the future possible formulation of a GBS vaccine.

Endocytosis‒Mediated Invasion and Pathogenicity of Streptococcus agalactiae in Rat Cardiomyocyte (H9C2).

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Pooja, Sharma; Pushpanathan, Muthuirulan; Gunasekaran, Paramasamy; Rajendhran, Jeyaprakash

2015-01-01

Streptococcus agalactiae infection causes high mortality in cardiovascular disease (CVD) patients, especially in case of setting prosthetic valve during cardiac surgery. However, the pathogenesis mechanism of S. agalactiae associate with CVD has not been well studied. Here, we have demonstrated the pathogenicity of S. agalactiae in rat cardiomyocytes (H9C2). Interestingly, both live and dead cells of S. agalactiae were uptaken by H9C2 cells. To further dissect the process of S. agalactiae internalization, we chemically inhibited discrete parts of cellular uptake system in H9C2 cells using genistein, chlorpromazine, nocodazole and cytochalasin B. Chemical inhibition of microtubule and actin formation by nocodazole and cytochalasin B impaired S. agalactiae internalization into H9C2 cells. Consistently, reverse‒ transcription PCR (RT‒PCR) and quantitative real time‒PCR (RT-qPCR) analyses also detected higher levels of transcripts for cytoskeleton forming genes, Acta1 and Tubb5 in S. agalactiae‒infected H9C2 cells, suggesting the requirement of functional cytoskeleton in pathogenesis. Host survival assay demonstrated that S. agalactiae internalization induced cytotoxicity in H9C2 cells. S. agalactiae cells grown with benzyl penicillin reduced its ability to internalize and induce cytotoxicity in H9C2 cells, which could be attributed with the removal of surface lipoteichoic acid (LTA) from S. agalactiae. Further, the LTA extracted from S. agalactiae also exhibited dose‒dependent cytotoxicity in H9C2 cells. Taken together, our data suggest that S. agalactiae cells internalized H9C2 cells through energy‒dependent endocytic processes and the LTA of S. agalactiae play major role in host cell internalization and cytotoxicity induction.

A multi locus variable number of tandem repeat analysis (MLVA scheme for Streptococcus agalactiae genotyping

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Mereghetti Laurent

2011-07-01

Full Text Available Abstract Background Multilocus sequence typing (MLST is currently the reference method for genotyping Streptococcus agalactiae strains, the leading cause of infectious disease in newborns and a major cause of disease in immunocompromised children and adults. We describe here a genotyping method based on multiple locus variable number of tandem repeat (VNTR analysis (MLVA applied to a population of S. agalactiae strains of various origins characterized by MLST and serotyping. Results We studied a collection of 186 strains isolated from humans and cattle and three reference strains (A909, NEM316 and 2603 V/R. Among 34 VNTRs, 6 polymorphic VNTRs loci were selected for use in genotyping of the bacterial population. The MLVA profile consists of a series of allele numbers, corresponding to the number of repeats at each VNTR locus. 98 MLVA genotypes were obtained compared to 51 sequences types generated by MLST. The MLVA scheme generated clusters which corresponded well to the main clonal complexes obtained by MLST. However it provided a higher discriminatory power. The diversity index obtained with MLVA was 0.960 compared to 0.881 with MLST for this population of strains. Conclusions The MLVA scheme proposed here is a rapid, cheap and easy genotyping method generating results suitable for exchange and comparison between different laboratories and for the epidemiologic surveillance of S. agalactiae and analyses of outbreaks.

The homodimeric GBS1074 from Streptococcus agalactiae

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Shukla, Anshuman; Pallen, Mark; Anthony, Mark; White, Scott A.

2010-01-01

The homodimeric nature of the ESAT-6 homologue GBS1074 and the potential for fibre-like assemblies are revealed by the 2 Å resolution crystal structure. ESAT-6 is a well characterized secreted protein from Mycobacterium tuberculosis and represents the archetype of the WXG100 family of proteins. Genes encoding ESAT-6 homologues have been identified in the genome of the human pathogen Streptococcus agalactiae; one of these genes, esxA, has been cloned and the recombinant protein has been crystallized. In contrast to M. tuberculosis ESAT-6, the crystal structure of GBS1074 reveals a homodimeric structure similar to homologous structures from Staphylococcus aureus and Helicobacter pylori. Intriguingly, GBS1074 forms elongated fibre-like assemblies in the crystal structure

Expression profiles of miRNAs from bovine mammary glands in response to Streptococcus agalactiae-induced mastitis.

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Pu, Junhua; Li, Rui; Zhang, Chenglong; Chen, Dan; Liao, Xiangxiang; Zhu, Yihui; Geng, Xiaohan; Ji, Dejun; Mao, Yongjiang; Gong, Yunchen; Yang, Zhangping

2017-08-01

This study aimed to describe the expression profiles of microRNAs (miRNAs) from mammary gland tissues collected from dairy cows with Streptococcus agalactiae-induced mastitis and to identify differentially expressed miRNAs related to mastitis. The mammary glands of Chinese Holstein cows were challenged with Streptococcus agalactiae to induce mastitis. Small RNAs were isolated from the mammary tissues of the test and control groups and then sequenced using the Solexa sequencing technology to construct two small RNA libraries. Potential target genes of these differentially expressed miRNAs were predicted using the RNAhybrid software, and KEGG pathways associated with these genes were analysed. A total of 18 555 913 and 20 847 000 effective reads were obtained from the test and control groups, respectively. In total, 373 known and 399 novel miRNAs were detected in the test group, and 358 known and 232 novel miRNAs were uncovered in the control group. A total of 35 differentially expressed miRNAs were identified in the test group compared to the control group, including 10 up-regulated miRNAs and 25 down-regulated miRNAs. Of these miRNAs, miR-223 exhibited the highest degree of up-regulation with an approximately 3-fold increase in expression, whereas miR-26a exhibited the most decreased expression level (more than 2-fold). The RNAhybrid software predicted 18 801 genes as potential targets of these 35 miRNAs. Furthermore, several immune response and signal transduction pathways, including the RIG-I-like receptor signalling pathway, cytosolic DNA sensing pathway and Notch signal pathway, were enriched in these predicted targets. In summary, this study provided experimental evidence for the mechanism underlying the regulation of bovine mastitis by miRNAs and showed that miRNAs might be involved in signal pathways during S. agalactiae-induced mastitis.

Streptococcus agalactiae Inhibits Candida albicans Hyphal Development and Diminishes Host Vaginal Mucosal TH17 Response

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Xiao-Yu Yu

2018-02-01

Full Text Available Streptococcus agalactiae and Candida albicans often co-colonize the female genital tract, and under certain conditions induce mucosal inflammation. The role of the interaction between the two organisms in candidal vaginitis is not known. In this study, we found that co-infection with S. agalactiae significantly attenuated the hyphal development of C. albicans, and that EFG1-Hwp1 signal pathway of C. albicans was involved in this process. In a mouse model of vulvovaginal candidiasis (VVC, the fungal burden and the levels of pro-inflammatory cytokines, IL-1β, IL-6 and TNF-α showed a increase on co-infection with S. agalactiae, while the level of TH17 T cells and IL-17 in the cervicovaginal lavage fluid were significantly decreased. Our results indicate that S. agalactiae inhibits C. albicans hyphal development by downregulating the expression of EFG1-Hwp1. The interaction between S. agalactiae and C. albicans may attenuate host vaginal mucosal TH17 immunity and contribute to mucosal colonization by C. albicans.

Two novel functions of hyaluronidase from Streptococcus agalactiae are enhanced intracellular survival and inhibition of proinflammatory cytokine expression.

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Wang, Zhaofei; Guo, Changming; Xu, Yannan; Liu, Guangjin; Lu, Chengping; Liu, Yongjie

2014-06-01

Streptococcus agalactiae is the causative agent of septicemia and meningitis in fish. Previous studies have shown that hyaluronidase (Hyl) is an important virulence factor in many Gram-positive bacteria. To investigate the role of S. agalactiae Hyl during interaction with macrophages, we inactivated the gene encoding extracellular hyaluronidase, hylB, in a clinical Hyl(+) isolate. The isogenic hylb mutant (Δhylb) displayed reduced survival in macrophages compared to the wild type and stimulated a significantly higher release of proinflammatory cytokines, such as interleukin-1β (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α), than the wild type in macrophages as well as in mice. Furthermore, only Hyl(+) strains could grow utilizing hyaluronic acid (HA) as the sole carbon source, suggesting that Hyl permits the organism to utilize host HA as an energy source. Fifty percent lethal dose (LD50) determinations in zebrafish demonstrated that the hylb mutant was highly attenuated relative to the wild-type strain. Experimental infection of BALB/c mice revealed that bacterial loads in the blood, spleen, and brain at 16 h postinfection were significantly reduced in the ΔhylB mutant compared to those in wild-type-infected mice. In conclusion, hyaluronidase has a strong influence on the intracellular survival of S. agalactiae and proinflammatory cytokine expression, suggesting that it plays a key role in S. agalactiae pathogenicity.

Pathogenicity of Human ST23 Streptococcus agalactiae to Fish and Genomic Comparison of Pathogenic and Non-pathogenic Isolates

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Rui Wang

2017-10-01

Full Text Available Streptococcus agalactiae, or Group B Streptococcus (GBS, is a major pathogen causing neonatal sepsis and meningitis, bovine mastitis, and fish meningoencephalitis. CC23, including its namesake ST23, is not only the predominant GBS strain derived from human and cattle, but also can infect a variety of homeothermic and poikilothermic species. However, it has never been characterized in fish. This study aimed to determine the pathogenicity of ST23 GBS to fish and explore the mechanisms causing the difference in the pathogenicity of ST23 GBS based on the genome analysis. Infection of tilapia with 10 human-derived ST23 GBS isolates caused tissue damage and the distribution of pathogens within tissues. The mortality rate of infection was ranged from 76 to 100%, and it was shown that the mortality rate caused by only three human isolates had statistically significant difference compared with fish-derived ST7 strain (P < 0.05, whereas the mortality caused by other seven human isolates did not show significant difference compared with fish-derived ST7 strain. The genome comparison and prophage analysis showed that the major genome difference between virulent and non-virulent ST23 GBS was attributed to the different prophage sequences. The prophage in the P1 region contained about 43% GC and encoded 28–39 proteins, which can mediate the acquisition of YafQ/DinJ structure for GBS by phage recombination. YafQ/DinJ belongs to one of the bacterial toxin–antitoxin (TA systems and allows cells to cope with stress. The ST23 GBS strains carrying this prophage were not pathogenic to tilapia, but the strains without the prophage or carrying the pophage that had gene mutation or deletion, especially the deletion of YafQ/DinJ structure, were highly pathogenic to tilapia. In conclusion, human ST23 GBS is highly pathogenic to fish, which may be related to the phage recombination.

ICESag37, a Novel Integrative and Conjugative Element Carrying Antimicrobial Resistance Genes and Potential Virulence Factors in Streptococcus agalactiae.

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Zhou, Kaixin; Xie, Lianyan; Han, Lizhong; Guo, Xiaokui; Wang, Yong; Sun, Jingyong

2017-01-01

ICE Sag37 , a novel integrative and conjugative element carrying multidrug resistance and potential virulence factors, was characterized in a clinical isolate of Streptococcus agalactiae . Two clinical strains of S. agalactiae , Sag37 and Sag158, were isolated from blood samples of new-borns with bacteremia. Sag37 was highly resistant to erythromycin and tetracycline, and susceptible to levofloxacin and penicillin, while Sag158 was resistant to tetracycline and levofloxacin, and susceptible to erythromycin. Transfer experiments were performed and selection was carried out with suitable antibiotic concentrations. Through mating experiments, the erythromycin resistance gene was found to be transferable from Sag37 to Sag158. Sma I-PFGE revealed a new Sma I fragment, confirming the transfer of the fragment containing the erythromycin resistance gene. Whole genome sequencing and sequence analysis revealed a mobile element, ICE Sag37 , which was characterized using several molecular methods and in silico analyses. ICE Sag37 was excised to generate a covalent circular intermediate, which was transferable to S. agalactiae . Inverse PCR was performed to detect the circular form. A serine family integrase mediated its chromosomal integration into rumA , which is a known hotspot for the integration of streptococcal ICEs. The integration site was confirmed using PCR. ICE Sag37 carried genes for resistance to multiple antibiotics, including erythromycin [ erm(B) ], tetracycline [ tet(O) ], and aminoglycosides [ aadE, aphA , and ant(6) ]. Potential virulence factors, including a two-component signal transduction system ( nisK/nisR ), were also observed in ICE Sag37 . S1-PFGE analysis ruled out the existence of plasmids. ICE Sag37 is the first ICE Sa2603 family-like element identified in S. agalactiae carrying both resistance and potential virulence determinants. It might act as a vehicle for the dissemination of multidrug resistance and pathogenicity among S. agalactiae .

Development of a loop-mediated isothermal amplification assay for the detection of Streptococcus agalactiae in bovine milk.

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Bosward, Katrina L; House, John K; Deveridge, Amber; Mathews, Karen; Sheehy, Paul A

2016-03-01

Streptococcus agalactiae is a well-characterized bovine mastitis pathogen that is known to be highly contagious and capable of spreading rapidly in affected dairy herds. Loop-mediated isothermal amplification (LAMP) is a novel molecular diagnostic method that has the capability to provide rapid, cost-effective screening for pathogens to support on-farm disease control and eradication programs. In the current study, a LAMP test was developed to detect S. agalactiae in milk. The assay was validated on a bank of existing clinical mastitis milk samples that had previously been identified as S. agalactiae positive via traditional microbiological culture techniques and PCR. The LAMP assay was conducted on bacterial colonies and DNA extracted from milk in tube- and plate-based formats using multiple detection platforms. The 1-h assay conducted at 64 °C exhibited repeatability (coefficient of variation) of 2.07% (tube) and 8.3% (plate), sensitivity to ~20 pg of extracted DNA/reaction, and specificity against a panel of known bacterial mastitis pathogens. Of the 109 known S. agalactiae isolates assessed by LAMP directly from bacterial cells in culture, 108 were identified as positive, in accordance with PCR analysis. The LAMP analysis from the corresponding milk samples indicated that 104 of these milks exhibited a positive amplification curve. Although exhibiting some limitations, this assay provides an opportunity for rapid screening of milk samples to facilitate on-farm management of this pathogen. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Molecular Characterization of Streptococcus agalactiae Causing Community- and Hospital-acquired Infections in Shanghai, China

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Haoqin Jiang

2016-08-01

Full Text Available Streptococcus agalactiae, a colonizing agent in pregnant women and the main cause of neonatal sepsis and meningitis, has been increasingly associated with invasive disease in nonpregnant adults. We collected a total of 87 non-repetitive S. agalactiae isolates causing community-acquired (CA and hospital-acquired (HA infections in nonpregnant adults from a teaching hospital in Shanghai between 2009 and 2013. We identified and characterized their antibiotic resistance, sequence type (ST, serotype, virulence, and biofilm formation. The most frequent STs were ST19 (29.9%, ST23 (16.1%, ST12 (13.8%, and ST1 (12.6%. ST19 had significantly different distributions between CA- and HA-group B Streptococci (GBS isolates. The most frequent serotypes were III (32.2%, Ia (26.4%, V (14.9%, Ib (13.8%, and II (5.7%. Serotype III/ST19 was significantly associated with levofloxacin resistance in all isoates. The HA-GBS multidrug resistant rate was much higher than that of CA-GBS. Virulence genes pavA, cfb were found in all isolates. Strong correlations exist between serotype Ib (CA and HA and surface protein genes spb1 and bac, serotype III (HA and surface protein gene cps and GBS pilus cluster. The serotype, epidemic clone, PFGE-based genotype, and virulence gene are closely related between CA-GBS and HA-GBS, and certain serotypes and clone types were significantly associated with antibiotic resistance. However, CA-GBS and HA-GBS still had significant differences in their distribution of clone types, antibiotic resistance, and specific virulence genes, which may provide a basis for infection control.

Infective Endocarditis Complicated by Intraventricular Abscesses, Pericarditis, and Mycotic Aneurysm Due to an Emerging Strain of Serotype VI Streptococcus agalactiae.

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Hirai, Nobuyasu; Kasahara, Kei; Uno, Kenji; Ogawa, Yoshihiko; Ogawa, Taku; Yonekawa, Shinsuke; Nakano, Ryuichi; Yano, Hisakazu; Sakagami, Azusa; Uemura, Takayuki; Okura, Hiroyuki; Saito, Yoshihiko; Yoshikawa, Masahide; Mikasa, Keiichi

2017-11-22

An increasing number of invasive infections due to Streptococcus agalactiae in non-pregnant adults have been reported. We report a case of infective endocarditis complicated by intraventricular abscesses, pericarditis, and mycotic aneurysm due to S. agalactiae belonging to ST681 with a capsular serotype VI in a woman with diabetes. The patient also had a myocardial infarction and was treated with percutaneous coronary intervention, pericardiocentesis, and 6 weeks of antibiotic treatment. Invasive infections due to serotype VI S. agalactiae are common in Asian countries such as Taiwan and Japan, so continuous monitoring of invasive S. agalactiae strains is warranted.

Visualization of the role of host heme on the virulence of the heme auxotroph Streptococcus agalactiae.

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Joubert, Laetitia; Dagieu, Jean-Baptiste; Fernandez, Annabelle; Derré-Bobillot, Aurélie; Borezée-Durant, Elise; Fleurot, Isabelle; Gruss, Alexandra; Lechardeur, Delphine

2017-01-16

Heme is essential for several cellular key functions but is also toxic. Whereas most bacterial pathogens utilize heme as a metabolic cofactor and iron source, the impact of host heme during bacterial infection remains elusive. The opportunist pathogen Streptococcus agalactiae does not synthesize heme but still uses it to activate a respiration metabolism. Concomitantly, heme toxicity is mainly controlled by the HrtBA efflux transporter. Here we investigate how S. agalactiae manages heme toxicity versus benefits in the living host. Using bioluminescent bacteria and heme-responsive reporters for in vivo imaging, we show that the capacity of S. agalactiae to overcome heme toxicity is required for successful infection, particularly in blood-rich organs. Host heme is simultaneously required, as visualized by a generalized infection defect of a respiration-negative mutant. In S. agalactiae, HrtBA expression responds to an intracellular heme signal via activation of the two-component system HssRS. A hssRS promoter-driven intracellular luminescent heme sensor was designed to identify host compartments that supply S. agalactiae with heme. S. agalactiae acquires heme in heart, kidneys, and liver, but not in the brain. We conclude that S. agalactiae response to heme is organ-dependent, and its efflux may be particularly relevant in late stages of infection.

The Adc/Lmb System Mediates Zinc Acquisition in Streptococcus agalactiae and Contributes to Bacterial Growth and Survival.

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Moulin, Pauline; Patron, Kévin; Cano, Camille; Zorgani, Mohamed Amine; Camiade, Emilie; Borezée-Durant, Elise; Rosenau, Agnès; Mereghetti, Laurent; Hiron, Aurélia

2016-12-15

The Lmb protein of Streptococcus agalactiae is described as an adhesin that binds laminin, a component of the human extracellular matrix. In this study, we revealed a new role for this protein in zinc uptake. We also identified two Lmb homologs, AdcA and AdcAII, redundant binding proteins that combine with the AdcCB translocon to form a zinc-ABC transporter. Expression of this transporter is controlled by the zinc concentration in the medium through the zinc-dependent regulator AdcR. Triple deletion of lmb, adcA, and adcAII, or that of the adcCB genes, impaired growth and cell separation in a zinc-restricted environment. Moreover, we found that this Adc zinc-ABC transporter promotes S. agalactiae growth and survival in some human biological fluids, suggesting that it contributes to the infection process. These results indicated that zinc has biologically vital functions in S. agalactiae and that, under the conditions tested, the Adc/Lmb transporter constitutes the main zinc acquisition system of the bacterium. A zinc transporter, composed of three redundant binding proteins (Lmb, AdcA, and AdcAII), was characterized in Streptococcus agalactiae This system was shown to be essential for bacterial growth and morphology in zinc-restricted environments, including human biological fluids. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

The economic benefit of treating subclinical Streptococcus agalactiae mastitis in lactating cows.

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Yamagata, M; Goodger, W J; Weaver, L; Franti, C

1987-12-15

The economic benefits of treating lactating cows for Streptococcus agalactiae mastitis were studied at a large (689 milking cows) central California dairy. Postcure milk production of case cows (infected, treated, and cured) was compared with production of paired control cows (uninfected) and was matched for yield, days in milk, days in gestation, and parity. A simulation was used to plot expected lactation curves for mastitic cows (infected, not treated) with characteristics similar to those of each control cow, and these curves were compared with actual case-cow lactation curves. The difference in actual and expected production was used to calculate net economic benefits of treatment. Comparison of expected with actual production indicated a net benefit from treatment of $396/cow for cows treated in early lactation and $237 for cows treated in midlactation, but a net loss of $55 for cows treated in late lactation. Lactation number did not have a significant impact on economic benefits of treatment. In contrast to other studies indicating no economic benefit from treating mastitis during lactation, this study's positive results may have been attributable to the high cure rate (98%) and the subclinical form of mastitis being treated. Streptococcus agalactiae mastitis treatment during early and midlactation would appear to be an economically justifiable option for dairy managers.

Structural characterization of the virulence factor nuclease A from Streptococcus agalactiae.

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Moon, Andrea F; Gaudu, Philippe; Pedersen, Lars C

2014-11-01

The group B pathogen Streptococcus agalactiae commonly populates the human gut and urogenital tract, and is a major cause of infection-based mortality in neonatal infants and in elderly or immunocompromised adults. Nuclease A (GBS_NucA), a secreted DNA/RNA nuclease, serves as a virulence factor for S. agalactiae, facilitating bacterial evasion of the human innate immune response. GBS_NucA efficiently degrades the DNA matrix component of neutrophil extracellular traps (NETs), which attempt to kill and clear invading bacteria during the early stages of infection. In order to better understand the mechanisms of DNA substrate binding and catalysis of GBS_NucA, the high-resolution structure of a catalytically inactive mutant (H148G) was solved by X-ray crystallography. Several mutants on the surface of GBS_NucA which might influence DNA substrate binding and catalysis were generated and evaluated using an imidazole chemical rescue technique. While several of these mutants severely inhibited nuclease activity, two mutants (K146R and Q183A) exhibited significantly increased activity. These structural and biochemical studies have greatly increased our understanding of the mechanism of action of GBS_NucA in bacterial virulence and may serve as a foundation for the structure-based drug design of antibacterial compounds targeted to S. agalactiae.

Phosphoglycerate kinase enhanced immunity of the whole cell of Streptococcus agalactiae in tilapia, Oreochromis niloticus.

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Wang, Yi-Ting; Huang, Hsing-Yen; Tsai, Ming-An; Wang, Pei-Chi; Jiang, Bo-Huang; Chen, Shih-Chu

2014-12-01

Streptococcus agalactiae is a Gram-positive bacterium and a severe aquaculture pathogen that can infect a wide range of warmwater fish species. The outer-surface proteins in bacterial pathogens play an important role in pathogenesis. We evaluated the immunogenicity of two of the identified surface proteins namely phosphoglycerate kinase (PGK) and ornithine carbamoyl-transferase (OCT). PGK and OCT were over-expressed and purified from Escherichia coli and used as the subunit vaccines in tilapia. Tilapia immunized with the S. agalactiae modified bacteria vaccine (whole cell preparations with recombinant PGK and OCT proteins) individually were tested for the efficacy. OCT and PGK combined with WC had a higher survival rate. A high-level protection and significant specific antibody responses against S. agalactiae challenge was observed upon the vaccinated tilapia with the purified PGK protein and S. agalactiae whole cells. The specific antibody titer against S. agalactiae antigen suggested that increased antibody titers were correlated with post-challenge survival rate. Il-1β expression profile was higher in PGK + WC-treated group. Tnf-α expression in the PGK + WC group was significantly increased. Taken together, our results suggested the combinations of recombinant protein and whole cell may elicit immune responses that reach greater protection than that of individual S. agalactiae components. Copyright © 2014 Elsevier Ltd. All rights reserved.

Physiological impact of transposable elements encoding DDE transposases in the environmental adaptation of Streptococcus agalactiae.

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Fléchard, Maud; Gilot, Philippe

2014-07-01

We have referenced and described Streptococcus agalactiae transposable elements encoding DDE transposases. These elements belonged to nine families of insertion sequences (ISs) and to a family of conjugative transposons (TnGBSs). An overview of the physiological impact of the insertion of all these elements is provided. DDE-transposable elements affect S. agalactiae in a number of aspects of its capability to adapt to various environments and modulate the expression of several virulence genes, the scpB-lmB genomic region and the genes involved in capsule expression and haemolysin transport being the targets of several different mobile elements. The referenced mobile elements modify S. agalactiae behaviour by transferring new gene(s) to its genome, by modifying the expression of neighbouring genes at the integration site or by promoting genomic rearrangements. Transposition of some of these elements occurs in vivo, suggesting that by dynamically regulating some adaptation and/or virulence genes, they improve the ability of S. agalactiae to reach different niches within its host and ensure the 'success' of the infectious process. © 2014 The Authors.

DETEKSI POLYMORPHISME DENGAN SUBSTITUSI NUKLEOTIDA TUNGGAL PADA Streptococcus agalactiae ISOLAT LOKAL INDONESIA

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Angela Mariana Lusiastuti

2015-12-01

Full Text Available Kasus penyakit pada budidaya ikan nila di wilayah di Jawa Barat, Jawa Tengah, Jawa Timur, Sulawesi Utara dan Papua Barat, disebabkan Streptococcus yang menyebabkan penyakit Streptococcosis di mana 80% disebabkan oleh grup B S. agalactiae. Tujuan penelitian ini adalah melakukan deteksi pada nukleotida isolat S. agalactiae untuk mengetahui sampai sejauh mana terjadinya nukleotida polimorfisme tunggal (SNP pada isolat tersebut. Identifikasi menggunakan PCR dilakukan terhadap 16S rDNA dan primer spesifik spesies terhadap S. agalactiae yaitu agal I 5’-ATAAGAGTAATTAACACATGTTAG-3’ (forward dan agal II 5’-ACTTCGGGTGTTACAAAC-3’(reverse dengan target 1250 bp. Produk PCR diamplifikasi terlebih dahulu menggunakan tujuh pasangan primer oligonukleotida yang berbeda yang didesain dari sekuens genom NEM316 GBS. Sekuens yang diperoleh dibandingkan dengan sekuens di Gene Bank database menggunakan National Center for Biotechnology Information Blast search tool. Hasil yang diperoleh ternyata ada dua basa yang berubah yaitu pada basa 24 dan basa 167. Pada basa 24 jelas terjadi subtitusi basa baru yaitu G, yang seharusnya tidak ada basa tersebut pada gen adhP-54 dan adhP-49 standar. Sedangkan pada basa 167 terjadi perbedaan basa dari seharusnya A pada standar menjadi G pada isolat 2.

A case of infective endocarditis along with a ruptured valve caused by Streptococcus agalactiae in an immunocompetent man.

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Suzuki, Kiyozumi; Hirai, Yuji; Morita, Fujiko; Uehara, Yuki; Oshima, Hiroko; Mitsuhashi, Kazunori; Amano, Atsushi; Naito, Toshio

2016-01-01

Streptococcus agalactiae ( S. agalactiae ) is a major cause of invasive disease in neonates and pregnant women, but has also recently been observed among non-pregnant adults, especially elderly persons or persons with underlying chronic disease. S. agalactiae is also a rare cause of infective endocarditis, and most cases require early surgery. We report the case of a 43-year-old previously healthy man who experienced rapid progressive culture-negative infective endocarditis with aortic valve vegetation and severe aortic regurgitation, which was complicated by lumbar spondylodiscitis. Emergency aortic valve replacement was performed on the day of his admission, which revealed a congenital bicuspid aortic valve was ruptured by the vegetation. The resected aortic valve specimen was submitted for 16S ribosomal RNA gene sequencing, which revealed that the pathogen was S. agalactiae . Therefore, S. agalactiae should be considered a potentially causative pathogen in cases of rapid progressive infective endocarditis, even if it occurs in a non-pregnant immunocompetent adult.

Evaluation of colorimetric loop-mediated isothermal amplification assay for visual detection of Streptococcus agalactiae and Streptococcus iniae in tilapia.

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Suebsing, R; Kampeera, J; Tookdee, B; Withyachumnarnkul, B; Turner, W; Kiatpathomchai, W

2013-10-01

Streptococcus agalactiae and Strep. iniae are bacterial pathogens that cause streptococcosis in many fish species. An accelerated colorimetric loop-mediated isothermal amplification (LAMP) assay with pre-addition of calcein was established, and the transmission and detection of Strep. agalactiae and Strep. iniae in tilapia under natural aquatic environment were investigated. A positive reaction was observed by a colour change from orange to green through the naked eyes after completion at 63°C for 30 min with 10 times higher sensitivity than that of nested PCR assays and without cross-amplification with other fish bacterial pathogens. All sample types of Nile and red tilapia (broodstock, fertilized egg, fry) were Strep. agalactiae- and Strep. iniae positive by this new method, implying that they could be vertically transmitted. With its application for screening broodstock and fry before stocking and for monitoring fish health in grow-out ponds, the method would become very useful in fish farming industry. The application of colorimetric LAMP with pre-addition of calcein offers simple, rapid and sensitive technique with applicability for small field laboratories. This technique explored the possible vertical transmission mode of Strep. agalactiae and Strep. iniae under natural aquatic environment. It could be such preliminary data provided for the screening broodstock before breeding and/or the specific-pathogen-free production. © 2013 The Society for Applied Microbiology.

Pathological analysis, detection of antigens, FasL expression analysis and leucocytes survival analysis in tilapia (Oreochromis niloticus) after infection with green fluorescent protein labeled Streptococcus agalactiae.

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Wang, Jingyuan; Wu, Jinying; Yi, Liyuan; Hou, Zengxin; Li, Wensheng

2017-03-01

The pathogenesis of Streptococcus agalactiae infection in tilapia has not been fully described. To understand this, we investigated the clinic-pathological features of acute experimental septicemia in tilapia (Oreochromis niloticus) after receiving an intra-peritoneal injection with S. agalactiae THN-1901GFP. Immunohistochemistry and sections of pathological tissues were used to estimate the level of damage in the head-kidney, liver, spleen and trunk-kidney. The expression of FasL was analyzed by western blotting in these samples based on their damage levels. Leucocytes were isolated from the head-kidney and incubated with S. agalactiae THN-1901GFP. Then, phagocytosis, programmed cell death and the expression of FasL were analyzed. The infected tissues showed varying degrees of necrosis and histolysis. The serous membrane of the intestine was dissolved by S. agalactiae THN-1901GFP. Antigens of S. agalactiae THN-1901GFP accumulated in different parts of the infected organs. In the head-kidney and spleen, the expression of FasL was up-regulated in parallel with increased tissue damage. After being incubated with S. agalactiae THN-1901GFP, the phagocytic capacity and ability were both very high and the expression of FasL remained high in leucocytes. S. agalactiae THN-1901GFP was able to survive for a long period of time after being engulfed by phagocytic cells. These findings offer insight into the pathogenesis of S. agalactiae infection in tilapia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of the Streptococcus agalactiae Virulence Regulator CovR on the Pathogenesis of Urinary Tract Infection.

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Sullivan, Matthew J; Leclercq, Sophie Y; Ipe, Deepak S; Carey, Alison J; Smith, Joshua P; Voller, Nathan; Cripps, Allan W; Ulett, Glen C

2017-02-01

Streptococcus agalactiae can cause urinary tract infection (UTI). The role of the S. agalactiae global virulence regulator, CovR, in UTI pathogenesis is unknown. We used murine and human bladder uroepithelial cell models of UTI and S. agalactiae mutants in covR and related factors, including β-hemolysin/cytolysin (β-h/c), surface-anchored adhesin HvgA, and capsule to study the role of CovR in UTI. We found that covR-deficient serotype III S. agalactiae 874391 was significantly attenuated for colonization in mice and adhesion to uroepithelial cells. Mice infected with covR-deficient S. agalactiae produced less proinflammatory cytokines than those infected with wild-type 874391. Acute cytotoxicity in uroepithelial cells triggered by covR-deficient but not wild-type 874391 was associated with significant caspase 3 activation. Mechanistically, covR mutation significantly altered the expression of several genes in S. agalactiae 874391 that encode key virulence factors, including β-h/c and HvgA, but not capsule. Subsequent mutational analyses revealed that HvgA and capsule, but not the β-h/c, exerted significant effects on colonization of the murine urinary tract in vivo. S. agalactiae CovR promotes bladder infection and inflammation, as well as adhesion to and viability of uroepithelial cells. The pathogenesis of S. agalactiae UTI is complex, multifactorial, and influenced by virulence effects of CovR, HvgA, and capsule. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Streptococcus agalactiae em gestantes: prevalência de colonização e avaliação da suscetibilidade aos antimicrobianos Streptococcus agalactiae in pregnant women: prevalence of colonization and antimicrobial susceptibility evaluation

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Irina Lermontov Borger

2005-10-01

Full Text Available OBJETIVOS: verificar a ocorrência de colonização por Streptococcus agalactiae em gestantes e avaliar a suscetibilidade das amostras isoladas aos antimicrobianos. MÉTODOS: foram avaliadas 167 grávidas entre a 32ª e a 41ª semana de gestação, independente da presença ou não de fatores de risco, atendidas no ambulatório de pré-natal entre fevereiro de 2003 e fevereiro de 2004. O material vaginal/anal, colhido com um único swab, foi inoculado em caldo Todd-Hewitt acrescido de ácido nalidíxico (15 µg/mL e gentamicina (8 µg/mL, com posterior subcultura no meio de ágar sangue. A identificação foi feita por meio da avaliação da morfologia e tipo de hemólise das colônias no meio de ágar sangue, teste da catalase, teste de cAMP e testes sorológicos. A avaliação da suscetibilidade aos antimicrobianos foi realizada pelos testes de difusão e de diluição em ágar. A análise estatística foi realizada por meio do teste de chi2; valores de p0,05. Todas as 32 amostras isoladas foram sensíveis a penicilina, cefotaxima, ofloxacina, cloranfenicol, vancomicina e meropenem. A resistência a eritromicina e clindamicina foi detectada em 9,4 e 6,2% das amostras, respectivamente. CONCLUSÕES: a incidência relativamente elevada (19,2% de colonização por S. agalactiae entre as gestantes avaliadas e o isolamento de amostras resistentes, especialmente aos antimicrobianos recomendados nos casos de alergia à penicilina, enfatizam a importância de detectar esta colonização no final da gravidez, associada à avaliação da suscetibilidade aos antimicrobianos, para uma prevenção eficaz da infecção neonatal.PURPOSE: to verify the occurrence of colonization by Streptococcus agalactiae in pregnant women attended at the prenatal outpatient clinic of the Teaching Maternity Hospital of Rio de Janeiro University (UFRJ and to evaluate the susceptibility of the isolates to antimicrobial agents. METHODS: a total of 167 pregnant women between the

Amperometric biosensor based on a single antibody of dual function for rapid detection of Streptococcus agalactiae.

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Vásquez, Gersson; Rey, Alba; Rivera, Camilo; Iregui, Carlos; Orozco, Jahir

2017-01-15

Pathogenic bacteria are responsible for several diseases in humans and in a variety of hosts. Detection of pathogenic bacteria is imperative to avoid and/or fight their potential harmful effects. This work reports on the first amperometric biosensor for the rapid detection of Streptococcus agalactiae (S. agalactiae). The biosensor relies on a single biotinylated antibody that immobilizes the bacteria on a screen-printed carbon electrode while is further linked to a streptavidin-conjugated HRP reporter. The biotinylated antibody provides selectivity to the biosensor whereas serves as an anchoring point to the reporter for further amplification of the electrochemical signal. The resultant immunosensor is simple, responds rapidly, and allows for the selective and highly sensitive quantification of S. agalactiae cells in a concentration range of 10 1 -10 7 CFUml -1 , with a detection limit of 10CFUml -1 . The approach not only enables a rapid detection and quantification of S. agalactiae in environmental samples but also opens up new opportunities for the simple fabrication of electrochemical immunosensors for different target pathogens. Copyright © 2016 Elsevier B.V. All rights reserved.

PENGARUH LAMA DAN SUHU PENYIMPANAN EKSTRAK DAUN SIRIH HIJAU (Piper betle linn DENGAN AQUADES TERHADAP DAYA HAMBAT BAKTERI Streptococcus agalactiae PENYEBAB MASTITIS PADA SAPI PERAH

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Muhammad Sanjaya Kusuma

2017-11-01

Full Text Available Green betle leaf (Piper betle L. is one of the plants used by the people of Indonesia for tradisional medicine. Green betle leaf contains antibacterial compounds consisting of phenol and its derivatives. This study aims to determine the antibacterial activity of green betle leaf (Piper betle L. againt the bacteria Streptococcus agalactiae caused mastitis in dairy cows. Bacterial inhibition test by paper disc method. Data analysis using ANOVA by Nested design with 6 treatment and 6 repetitions. The results of this study green betle leaf (Piper betle L. extract inhibiting the growth of bacteria Streptococcus agalactiae was significantly different (P<0,01. The conclusion were the extract of green betel leaf (Piper betle L. can inhibit the growth of Streptococcus agalactiae and storage temperature has no effect, but storage periode gives effect the quality of green betel leaf extract (Piper betle L., so that the leaf extract storage green betel with distilled solvent recommended on 2nd days at refrigerator.

The highly dynamic CRISPR1 system of Streptococcus agalactiae controls the diversity of its mobilome.

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Lopez-Sanchez, Maria-José; Sauvage, Elisabeth; Da Cunha, Violette; Clermont, Dominique; Ratsima Hariniaina, Elisoa; Gonzalez-Zorn, Bruno; Poyart, Claire; Rosinski-Chupin, Isabelle; Glaser, Philippe

2012-09-01

Clustered regularly interspaced short palindromic repeats (CRISPR) confer immunity against mobile genetic elements (MGEs) in prokaryotes. Streptococcus agalactiae, a leading cause of neonatal infections contains in its genome two CRISPR/Cas systems. We show that type 1-C CRISPR2 is present in few strains but type 2-A CRISPR1 is ubiquitous. Comparative sequence analysis of the CRISPR1 spacer content of 351 S. agalactiae strains revealed that it is extremely diverse due to the acquisition of new spacers, spacer duplications and spacer deletions that witness the dynamics of this system. The spacer content profile mirrors the S. agalactiae population structure. Transfer of a conjugative transposon targeted by CRISPR1 selected for spacer rearrangements, suggesting that deletions and duplications pre-exist in the population. The comparison of protospacers located within MGE or the core genome and protospacer-associated motif-shuffling demonstrated that the GG motif is sufficient to discriminate self and non-self and for spacer selection and integration. Strikingly more than 40% of the 949 different CRISPR1 spacers identified target MGEs found in S. agalactiae genomes. We thus propose that the S. agalactiae type II-A CRISPR1/Cas system modulates the cohabitation of the species with its mobilome, as such contributing to the diversity of MGEs in the population. © 2012 Blackwell Publishing Ltd.

Molecular Methods for Typing of Streptococcus agalactiae with Special Emphasis on the Development and Validation of a Multi-Locus Variable Number of Tandem Repeats Assay (MLVA)

OpenAIRE

Radtke, Andreas

2012-01-01

Molekylære metoder for typing av Streptococcus agalactiae med særlig vektlegging av utvikling og validering av et multi-locus variable number of tandem repeats assay (MLVA) Sammendraget: Streptococcus agalactiae eller gruppe B streptokokker (GBS) forårsaker livsfarlige infeksjoner hos nyfødte, gravide eller voksne med kroniske sykdommer. Den forårsaker også jurbetennelse i storfe. Typing av GBS gir innblikk i bakteriens epidemiologi og dens fylogenetiske slektskap. Ulike deler av bakterie...

KERENTANAN IKAN NILA SULTANA, RED NIFI, SRIKANDI DAN AUREUS TERHADAP INFEKSI BAKTERI Streptococcus agalactiae

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Rita Febrianti

2015-06-01

Full Text Available Penelitian ini bertujuan untuk menguji kerentanan empat strain ikan nila, yaitu: Sultana, Red NIFI, Srikandi, dan Aureus terhadap infeksi bakteri Streptococcus agalactiae. Ikan uji berukuran 15-20 g/ekor dan berasal dari populasi, serta batch umur yang sama. Infeksi bakteri S. agalactiae dilakukan secara buatan melalui penyuntikan intra peritoneal (IP pada dosis 104 cfu/mL, sedangkan kelompok kontrol diinjeksi dengan larutan Phosphate Buffered Saline (PBS. Pengamatan dilakukan terhadap gejala klinis dan mortalitas ikan uji yang berlangsung selama 14 hari. Hasil penelitian menunjukkan bahwa seluruh strain ikan nila mengalami respons yang sama terhadap infeksi bakteri S. agalactie yang ditandai dengan munculnya gejala klinis seperti: warna gelap/menghitam, sirip geripis, nekrosa pada mulut, mata menonjol, opaque, ulcer, dan dropsy. Kerentanan tertinggi terhadap infeksi bakteri S. agalactiae yang dimanifestasikan dengan rataan persentase mortalitas ikan uji diperoleh pada ikan nila Aureus sebesar 72%, Sultana 50%, Srikandi 36%, Red NIFI sebesar 24%, dan kontrol tidak ada mortalitas. Setelah diuji tantang, kadar limfosit mengalami kenaikan, netrofil dan monosit mengalami penurunan.

Molecular and bacteriological investigation of subclinical mastitis caused by Staphylococcus aureus and Streptococcus agalactiae in domestic bovids from Ismailia, Egypt.

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Elhaig, Mahmoud Mohey; Selim, Abdelfattah

2015-02-01

A study was carried out to establish the prevalence of subclinical mastitis (SCM) in smallholder dairy farms in Ismailia, Egypt. A total of 340 milking cows and buffaloes were sampled from 60 farms, and 50 nasal swabs were collected from consenting farm workers. Milk samples were subjected to California mastitis test (CMT) and the positive samples were examined by bacterial culture and PCR to identify etiological agents. Based on CMT, the prevalence of SCM was 71.6 % in cattle and 43.5 % in buffaloes while the prevalence was 25.2 % at cow-quarter level and 21.7 % at buffaloes-quarter level. Bacteriological analysis showed that the most frequently identified bacteria were Staphylococcus (S.) aureus (38.3 %) and Streptococcus (Str.) agalactiae (20 %). The diagnostic sensitivity of PCR compared to bacterial culture was superior with S. aureus and Str. agalactiae detection being 41 and 22.6 %, respectively. Furthermore, methicillin-resistant S. aureus (MRSA) strains occurred in 52.2 and 45 % of isolates of animals and workers, respectively. Subclinical mastitis due to S. aureus and Str. agalactiae is endemic in smallholder dairy herds in Ismailia. The occurrence of MRSA in animals and workers highlights a need for wide epidemiological studies of MRSA and adopting control strategies.

INHIBITION OF Malus sylvestris Mill. PEELEXTRACT USING ETANOL SOLVENT ON THE GROWTH OF Streptococcus agalactiae AND Escherichia coli CAUSING MASTITIS

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Kanzul Kamal Putra

2017-03-01

Full Text Available The purpose of this research was to find the resistibility of Manalagi apple peel extract, using etanol, to the growth of was to determine the antibacterial activity of Manalagi apple peel (Malus sylvestris Mill extract in various solvent using ethanol concentration against the growth of Streptococcus agalactiae and Escherichia coli bacteria that causing mastitis.The research methodwas experimental using Completely Randomized Design with 4 treatments and 6 replication. The treatments consisted of P1 (10%, P2 (20%, P3 (50% concentrations and P0 (10% iodips as the control. The variable measured was diameter of inhibition zone. The data were analyzed using ANOVA and continued by Duncan’s New Multiple Range Test (DMRT test if there was significantly difference result. The result of the inhibition zone of Manalagi apple peel extract using etanol in preventing the growth of Streptococcus agalactiae and Escherichia coli bacteria was different (P<0,01. In P2 (30% concentration, the extract resistibility to the growth of Streptococcus agalactiae bacteria was equivalent to P0 (iodips and in P3 (50% concentration, the extract resistibility to Escherichia coli bacteria was greater than P0 (iodips. Manalagi apple peel extract using etanol can be used as a natural antiseptic solution for teat dipping on dairy cows. The recommendation from the research was using extract Manalagi apple peel with etanol solvent concentration of 30% as a solution of teat dipping.   Keywords : Manalagi apple peel, Teat dipping, Mastitis, Streptococcus agalactiaeand Escherichia coli

Resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae and S. agalactiae Ib is heritable but not correlated

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Tilapia (Oreochromis sp.) are an important source of protein with an economic value approaching US $8 billion yearly. Streptococcal disease, caused by Streptococcus iniae and S. agalactiae (both Gram positive bacteria), is an emerging or re-emerging disease negatively affecting tilapia aquaculture w...

Combination of garlic - shatterstone herb powder to control Streptococcus agalactiae infection in tilapia

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Ririn Nurul Fauziah

2015-10-01

Full Text Available ABSTRACT This study was aimed at determining potential of combination powder of garlic Allium sativum-shatterstone herb Phyllanthus niruri supplemented in feed against S. agalactiae infection in tilapia. Four concentrations of combination powder of A. sativum-P. Niruri; 20+5, 20+10, 20+15 and 20+20 ppt respectively were investigated for their ability to inhibit bacterial fish pathogen. Combination dose of 20+15 ppt produced the highest inhibitory zones in in vitro test. In vivo test consisted of three treatments with three replications, namely positive control (K+, negative control (K- and the treatment of A. sativum-P. niruri suplemented in feed (BM.  The test perfomed on tilapia with weight of 10.33 ± 1.63 g and were reared at density of 10 ind/aquarium. The fish was fed for 14 days, then injected intraperitoneally with 0.1 mL S. agalactiae at concentration of 105 cfu/mL for positive control and BM groups. Survival, growth rate, feed response, hematological and water quality parameters were observed for 10 days. This study showed that the suplemented-feed-fish (BM showed better growth rate, feed response, and survival (83.3% than positive control (36.7% at P<0.05. In addition, A. sativum-P. niruri suplemented in feed was also able to enhance the immune response by increasing phagocytic activity. Keywords: Streptococcus agalactiae, phytopharmacy, Allium sativum-Phyllanthus niruri, tilapia  ABSTRAK Penelitian ini bertujuan untuk menganalisis potensi campuran tepung bawang putih Allium sativum-meniran Phyllanthus niruri dalam pakan terhadap pencegahan infeksi bakteri S. agalactiae pada ikan nila. Empat konsentrasi campuran tepung bawang putih-meniran yaitu 20+5 ppt, 20+10 ppt, 20+15 ppt dan 20+20 ppt masing-masing diuji kemampuannya dalam  menghambat bakteri patogen pada ikan. Campuran dosis 20+15 ppt menghasilkan zona hambat terbaik dalam uji in vitro. Uji in vivo terdiri atas tiga perlakuan dengan tiga ulangan yaitu kontrol positif

Fulminant Necrotizing Fasciitis and Toxic Shock Syndrome Caused by Streptococcus agalactiae

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Emin UYSAL

2018-03-01

Full Text Available Necrotizing fasciitis is a rare and life-threatening soft tissue infection that spreads rapidly and involves the skin, subcutaneous tissue, fascia, and muscle layer. The treatment is possible by initiating appropriate antibiotherapy for the clinically suspected cause and by performing surgical intervention quickly and aggressively. However, it should be known that necrotizing fasciitis is a disease that is difficult to manage despite all interventions, effective treatment protocols, and patient care. This article presents the case of a 60-year-old patient with diabetes mellitus who died of toxic shock syndrome with fulminant necrotizing fasciitis caused by Streptococcus agalactiae.

Comparative genome analysis identifies two large deletions in the genome of highly-passaged attenuated Streptococcus agalactiae strain YM001 compared to the parental pathogenic strain HN016.

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Wang, Rui; Li, Liping; Huang, Yan; Luo, Fuguang; Liang, Wanwen; Gan, Xi; Huang, Ting; Lei, Aiying; Chen, Ming; Chen, Lianfu

2015-11-04

Streptococcus agalactiae (S. agalactiae), also known as group B Streptococcus (GBS), is an important pathogen for neonatal pneumonia, meningitis, bovine mastitis, and fish meningoencephalitis. The global outbreaks of Streptococcus disease in tilapia cause huge economic losses and threaten human food hygiene safety as well. To investigate the mechanism of S. agalactiae pathogenesis in tilapia and develop attenuated S. agalactiae vaccine, this study sequenced and comparatively analyzed the whole genomes of virulent wild-type S. agalactiae strain HN016 and its highly-passaged attenuated strain YM001 derived from tilapia. We performed Illumina sequencing of DNA prepared from strain HN016 and YM001. Sequencedreads were assembled and nucleotide comparisons, single nucleotide polymorphism (SNP) , indels were analyzed between the draft genomes of HN016 and YM001. Clustered regularly interspaced short palindromic repeats (CRISPRs) and prophage were detected and analyzed in different S. agalactiae strains. The genome of S. agalactiae YM001 was 2,047,957 bp with a GC content of 35.61 %; it contained 2044 genes and 88 RNAs. Meanwhile, the genome of S. agalactiae HN016 was 2,064,722 bp with a GC content of 35.66 %; it had 2063 genes and 101 RNAs. Comparative genome analysis indicated that compared with HN016, YM001 genome had two significant large deletions, at the sizes of 5832 and 11,116 bp respectively, resulting in the deletion of three rRNA and ten tRNA genes, as well as the deletion and functional damage of ten genes related to metabolism, transport, growth, anti-stress, etc. Besides these two large deletions, other ten deletions and 28 single nucleotide variations (SNVs) were also identified, mainly affecting the metabolism- and growth-related genes. The genome of attenuated S. agalactiae YM001 showed significant variations, resulting in the deletion of 10 functional genes, compared to the parental pathogenic strain HN016. The deleted and mutated functional genes all

Molecular epidemiology and strain-specific characteristics of Streptococcus agalactiae at the herd and cow level.

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Mahmmod, Y S; Klaas, I C; Katholm, J; Lutton, M; Zadoks, R N

2015-10-01

Host-adaptation of Streptococcus agalactiae subpopulations has been described whereby strains that are commonly associated with asymptomatic carriage or disease in people differ phenotypically and genotypically from those causing mastitis in dairy cattle. Based on multilocus sequence typing (MLST), the most common strains in dairy herds in Denmark belong to sequence types (ST) that are also frequently found in people. The aim of this study was to describe epidemiological and diagnostic characteristics of such strains in relation to bovine mastitis. Among 1,199 cattle from 6 herds, cow-level prevalence of S. agalactiae was estimated to be 27.4% based on PCR and 7.8% based on bacteriological culture. Quarter-level prevalence was estimated at 2.8% based on bacteriological culture. Per herd, between 2 and 26 isolates were characterized by pulsed-field gel electrophoresis (PFGE) and MLST. Within each herd, a single PFGE type and ST predominated, consistent with a contagious mode of transmission or point source infection within herds. Evidence of within-herd evolution of S. agalactiae was detected with both typing methods, although ST belonged to a single clonal complex (CC) per herd. Detection of CC23 (3 herds) was associated with significantly lower approximate count (colony-forming units) at the quarter level and significantly lower cycle threshold value at the cow level than detection of CC1 (2 herds) or CC19 (1 herd), indicating a lower bacterial load in CC23 infections. Median values for the number of infected quarters and somatic cell count (SCC) were numerically but not significantly lower for cows infected with CC23 than for cows with CC1 or CC19. For all CC, an SCC threshold of 200,000 cells/mL was an unreliable indicator of infection status, and prescreening of animals based on SCC as part of S. agalactiae detection and eradication campaigns should be discouraged. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights

A new mosaic integrative and conjugative element from Streptococcus agalactiae carrying resistance genes for chloramphenicol (catQ) and macrolides [mef(I) and erm(TR)].

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Morici, Eleonora; Simoni, Serena; Brenciani, Andrea; Giovanetti, Eleonora; Varaldo, Pietro E; Mingoia, Marina

2017-01-01

To investigate the genetic basis of catQ-mediated chloramphenicol resistance in Streptococcus agalactiae. Two clinical strains of catQ-positive chloramphenicol-resistant S. agalactiae (Sag236 and Sag403) were recently isolated, typed (MLST, PFGE pulsotypes, capsular types) and their antibiotic resistances investigated by phenotypic and genotypic approaches. Several molecular methods (PCR mapping, restriction assays, Southern blotting, sequencing and sequence analysis, conjugal transfer assays) were used to determine the genetic context of catQ and characterize a genetic element detected in the isolates. Sag236 and Sag403 shared the same ST (ST19), but exhibited a different capsular type (III and V, respectively) and pulsotype. Both harboured the macrolide resistance genes mef(I) and erm(TR) and the tetracycline resistance gene tet(M). Accordingly, they were resistant to chloramphenicol, erythromycin and tetracycline. catQ and mef(I) were associated in an IQ module that was indistinguishable in Sag236 and Sag403. In mating assays, chloramphenicol and erythromycin resistance proved transferable, at low frequency, only from Sag236. Transconjugants carried not only catQ and mef(I), but also erm(TR), suggesting a linkage of the three resistance genes in a mobile element, which, though seemingly non-mobile, was also detected in Sag403. The new element (designated ICESag236, ∼110 kb) results from recombination of two integrative and conjugative elements (ICEs) originally described in different streptococcal species: S. agalactiae ICESagTR7, carrying erm(TR); and Streptococcus pneumoniae ICESpn529IQ, carrying the prototype IQ module. These findings strengthen the notion that widespread streptococcal ICEs may form mosaics that enhance their diversity and spread, broaden their host range and carry new cargo genes. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions

Role of the Group B antigen of Streptococcus agalactiae: a peptidoglycan-anchored polysaccharide involved in cell wall biogenesis.

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Élise Caliot

Full Text Available Streptococcus agalactiae (Group B streptococcus, GBS is a leading cause of infections in neonates and an emerging pathogen in adults. The Lancefield Group B carbohydrate (GBC is a peptidoglycan-anchored antigen that defines this species as a Group B Streptococcus. Despite earlier immunological and biochemical characterizations, the function of this abundant glycopolymer has never been addressed experimentally. Here, we inactivated the gene gbcO encoding a putative UDP-N-acetylglucosamine-1-phosphate:lipid phosphate transferase thought to catalyze the first step of GBC synthesis. Indeed, the gbcO mutant was unable to synthesize the GBC polymer, and displayed an important growth defect in vitro. Electron microscopy study of the GBC-depleted strain of S. agalactiae revealed a series of growth-related abnormalities: random placement of septa, defective cell division and separation processes, and aberrant cell morphology. Furthermore, vancomycin labeling and peptidoglycan structure analysis demonstrated that, in the absence of GBC, cells failed to initiate normal PG synthesis and cannot complete polymerization of the murein sacculus. Finally, the subcellular localization of the PG hydrolase PcsB, which has a critical role in cell division of streptococci, was altered in the gbcO mutant. Collectively, these findings show that GBC is an essential component of the cell wall of S. agalactiae whose function is reminiscent of that of conventional wall teichoic acids found in Staphylococcus aureus or Bacillus subtilis. Furthermore, our findings raise the possibility that GBC-like molecules play a major role in the growth of most if not all beta-hemolytic streptococci.

Development of live attenuated Streptococcus agalactiae vaccine for tilapia via continuous passage in vitro.

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Li, L P; Wang, R; Liang, W W; Huang, T; Huang, Y; Luo, F G; Lei, A Y; Chen, M; Gan, X

2015-08-01

Fish Streptococcus agalactiae (S. agalactiae) seriously harms the world's aquaculture industry and causes huge economic losses. This study aimed to develop a potential live attenuated vaccine of S. agalactiae. Pre-screened vaccine candidate strain S. agalactiae HN016 was used as starting material to generate an attenuated strain S. agalactiae YM001 by continuous passage in vitro. The biological characteristics, virulence, and stability of YM001 were detected, and the protective efficacy of YM001 immunization in tilapia was also determined. Our results indicated that the growth, staining, characteristics of pulsed-field gel electrophoresis (PFGE) genotype, and virulence of YM001 were changed significantly as compared to the parental strain HN016. High doses of YM001 by intraperitoneal (IP) injection (1.0 × 10(9) CFU/fish) and oral gavage (1.0 × 10(10) CFU/fish) respectively did not cause any mortality and morbidity in tilapia. The relative percent survivals (RPSs) of fishes immunized with YM001 (1.0 × 10(8) CFU/fish, one time) via injection, immersion, and oral administration were 96.88, 67.22, and 71.81%, respectively, at 15 days, and 93.61, 60.56, and 53.16%, respectively, at 30 days. In all tests with 1-3 times of immunization in tilapia, the dosages at 1 × 10(8) and 1 × 10(9) CFU/fish displayed the similar best results, whereas the immunoprotection of the dosages at 1 × 10(6) and 1 × 10(7) CFU/fish declined significantly (P 0.05). The level of protective antibody elicited by oral immunization was significantly higher compared to that of the control group (P S. agalactiae strain YM001; oral immunization of tilapia with this strain produced a good immune protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Short communication: In vitro antimicrobial susceptibility of Mycoplasma agalactiae strains isolated from dairy goats.

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Paterna, A; Sánchez, A; Gómez-Martín, A; Corrales, J C; De la Fe, C; Contreras, A; Amores, J

2013-01-01

This study examined the susceptibility to several antimicrobials of 28 isolates of Mycoplasma agalactiae obtained from goats in a region (southeastern Spain) where contagious agalactia is endemic. For each isolate, the minimum inhibitory concentration (MIC) against 12 antimicrobials of the quinolone, macrolide, aminoglycoside, and tetracycline families was determined. The antimicrobials with the lowest MIC were enrofloxacin, ciprofloxacin, tylosin, and doxycycline, all with MIC90 (concentration at which growth of 90% of the isolates is inhibited) <1 µg/mL. Norfloxacin (a quinolone) showed a wide MIC range (0.1-12.8 µg/mL), suggesting a resistance mechanism toward this antimicrobial that was not elicited by enrofloxacin or ciprofloxacin (the other quinolones tested). Erythromycin showed the highest MIC90 such that its use against Mycoplasma agalactiae is not recommended. Finally, Mycoplasma agalactiae isolates obtained from goat herds with clinical symptoms of contagious agalactia featured higher MIC90 and MIC50 (concentration at which growth of 50% of the isolates is inhibited) values for many of the antimicrobials compared with isolates from asymptomatic animals. The relationship between the extensive use of antimicrobials in herds with clinical contagious agalactia and variations in MIC requires further study. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Isolation and prevalence of Mycoplasma agalactiae in Kurdish sheep in Kurdistan, Iran

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Mohammad Khezri

Full Text Available Aim: Ruminant Mycoplasmosis are important diseases worldwide and several are listed by the World Organization for Animal Health (OIE to be of major economic significant. The aim of this study was to isolation mycoplasmas from sheep presenting contagious agalactiae (CA in Kurdistan in the West of Iran. Materials and Methods: Sixty-nine samples included (milk, conjuctiva swabs, synovial fluid and ear canal swabs were examined by PCR assay during 2011-2012. DNA was extracted from enriched samples. Two primers (forward and reverse amplify a 163bp region of 16S rRNA gene of Mycoplasma genus and two primers amplify 375bp region of 16S rRNA gene of Mycoplasma agalactiae (M. agalactiae species were used. Results: This proved that 46 samples (66.7% were infected with Mycoplasma in culture and PCR test, respectively. On the PCR test, 15 isolates (32.6% examined were positive for M. agalactiae that showed specific amplicon at 375bp. All Mycoplasma positive samples were analyzed for M. agalactiae infection by PCR method and 31 isolates (67.4% examined were negative for M. agalactiae. The finding of other mycoplasmas with significant epidemiology challenges existing plans for the control of CA in sheep population in Iran. Conclusion: The results of the present study show that M. agalactiae in CA disease in Kurdistan Province, 32.6% involved. In Iran, only M. agalactiae vaccines are commercially available, thus, the animals are not protected against these other species. [Vet World 2012; 5(12.000: 727-731

Streptococcus agalactiae impairs cerebral bioenergetics in experimentally infected silver catfish.

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Baldissera, Matheus D; Souza, Carine F; Parmeggiani, Belisa S; Santos, Roberto C V; Leipnitz, Guilhian; Moreira, Karen L S; da Rocha, Maria Izabel U M; da Veiga, Marcelo L; Baldisserotto, Bernardo

2017-10-01

It is becoming evident that bacterial infectious diseases affect brain energy metabolism, where alterations of enzymatic complexes of the mitochondrial respiratory chain and creatine kinase (CK) lead to an impairment of cerebral bioenergetics which contribute to disease pathogenesis in the central nervous system (CNS). Based on this evidence, the aim of this study was to evaluate whether alterations in the activity of complex IV of the respiratory chain and CK contribute to impairment of cerebral bioenergetics during Streptococcus agalactiae infection in silver catfish (Rhamdia quelen). The activity of complex IV of the respiratory chain in brain increased, while the CK activity decreased in infected animals compared to uninfected animals. Brain histopathology revealed inflammatory demyelination, gliosis of the brain and intercellular edema in infected animals. Based on this evidence, S. agalactiae infection causes an impairment in cerebral bioenergetics through the augmentation of complex IV activity, which may be considered an adaptive response to maintain proper functioning of the electron respiratory chain, as well as to ensure ongoing electron flow through the electron transport chain. Moreover, inhibition of cerebral CK activity contributes to lower availability of ATP, contributing to impairment of cerebral energy homeostasis. In summary, these alterations contribute to disease pathogenesis linked to the CNS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Diversity of prophage DNA regions of Streptococcus agalactiae clonal lineages from adults and neonates with invasive infectious disease.

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Mazen Salloum

Full Text Available The phylogenetic position and prophage DNA content of the genomes of 142 S. agalactiae (group-B streptococcus, GBS isolates responsible for bacteremia and meningitis in adults and neonates were studied and compared. The distribution of the invasive isolates between the various serotypes, sequence types (STs and clonal complexes (CCs differed significantly between adult and neonatal isolates. Use of the neighbor-net algorithm with the PHI test revealed evidence for recombination in the population studied (PHI, P = 2.01 × 10(-6, and the recombination-mutation ratio (R/M was 6:7. Nevertheless, the estimated R/M ratio differed between CCs. Analysis of the prophage DNA regions of the genomes of the isolates assigned 90% of the isolates to five major prophage DNA groups: A to E. The mean number of prophage DNA fragments amplified per isolate varied from 2.6 for the isolates of prophage DNA group E to 4.0 for the isolates of prophage DNA group C. The isolates from adults and neonates with invasive diseases were distributed differently between the various prophage DNA groups (P < 0.00001. Group C prophage DNA fragments were found in 52% of adult invasive isolates, whereas 74% of neonatal invasive isolates had prophage DNA fragments of groups A and B. Differences in prophage DNA content were also found between serotypes, STs and CCs (P < 0.00001. All the ST-1 and CC1 isolates, mostly of serotype V, belonged to the prophage DNA group C, whereas 84% of the ST-17 and CC17 isolates, all of serotype III, belonged to prophage DNA groups A and B. These data indicate that the transduction mechanisms, i.e., gene transfer from one bacterium to another by a bacteriophage, underlying genetic recombination in S. agalactiae species, are specific to each intraspecies lineage and population of strains responsible for invasive diseases in adults and neonates.

Protective efficacy of cationic-PLGA microspheres loaded with DNA vaccine encoding the sip gene of Streptococcus agalactiae in tilapia.

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Ma, Yan-Ping; Ke, Hao; Liang, Zhi-Ling; Ma, Jiang-Yao; Hao, Le; Liu, Zhen-Xing

2017-07-01

Streptococcus agalactiae (S. agalactiae) is an important fish pathogen, which has received more attention in the past decade due to the increasing economic losses in the tilapia industry worldwide. As existing effective vaccines of S. agalactiae in fish have obvious disadvantage, to select immunoprotective antigens and package materials would undoubtedly contribute to the development of novel oral vaccines. In the present study, surface immunogenic protein (sip) was selected from the S. agalactiae serovar I a genomes as immunogenic protein in DNA vaccine form with cationic chitosan and biodegradable and biocompatible PLGA. The pcSip plasmid in cationic-PLGA was successfully expressed in tissues of immunized tilapia and the immunogenicity was assessed in tilapia challenge model. A significant increase was observed in the cytokine levels of IL-1β, TNF-α, CC1, CC2 in spleen and kidney tissues. Furthermore, immunized tilapia conferred different levels of protection against challenge with a lethal dose of highly virulent serovar I a S. agalactiae. Our results indicated that the pcSip plasmid in cationic-PLGA induced high level of antibodies and protection against S. agalactiae infection, could be effective oral DNA vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.

GapA, a potential vaccine candidate antigen against Streptococcus agalactiae in Nile tilapia (Oreochromis niloticus).

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Zhang, Ze; Yu, Angen; Lan, Jiangfeng; Zhang, Hua; Hu, Minqiang; Cheng, Jiewei; Zhao, Lijuan; Lin, Li; Wei, Shun

2017-04-01

Streptococcosis due to the bacterium Streptococcus agalactiae (S. agalactiae) has resulted in enormous economic losses in aquaculture worldwide, especially in the tilapia culture industry. Previously, there were limited vaccines that could be employed against streptococcosis in tilapia. This study aimed to develop a vaccine candidate using the glyceraldehyde-phosphate dehydrogenase protein (GapA) of S. agalactiae encoded by the gapA gene. Tilapia were intraperitoneally injected with PBS, PBS + Freund's adjuvant, PBS + Montanide's adjuvant, GapA + Freund's adjuvant, GapA + Montanide's adjuvant, killed S. agalactiae whole cells (WC)+Freund's adjuvant, or killed S. agalactiae whole cells (WC)+ Montanide's adjuvant. They were then challenged with S. agalactiae, and the relative percentage survival (RPS) was monitored 14 days after the challenge. The highest RPSs were observed in the WC groups, with 76.7% in WC + Freund's adjuvant and 74.4% in WC + Montanide's adjuvant groups; these were followed by the GapA groups, with 63.3% in GapA + Freund's adjuvant and 45.6% in GapA + Montanide's adjuvant groups. The RPS of the PBS group was 0%, and those of PBS + Freund's adjuvant and PBS + Montanide's adjuvant groups were 6.7% and 3.3%, respectively. Additionally, the IgM antibody responses elicited in GapA groups and WC groups were significantly higher than those in PBS groups. Furthermore, the expressions of cytokine (IL-1β and TNF-α) mRNAs in the GapA groups and WC groups were significantly higher than those in the PBS groups. Taken together, these results reveal that the GapA protein is a promising vaccine candidate that could be used to prevent streptococcosis in tilapia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of a single-dose recombinant CAMP factor entrapping poly(lactide-co-glycolide) microspheres-based vaccine against Streptococcus agalactiae.

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Liu, Gang; Yin, Jinhua; Barkema, Herman W; Chen, Liben; Shahid, Muhammad; Szenci, Otto; De Buck, Jeroen; Kastelic, John P; Han, Bo

2017-03-01

Streptococcus agalactiae is an important contagious bovine mastitis pathogen. Although it is well controlled and even eradicated in most Northern European and North American dairy herds, the prevalence of this pathogen remains very high in China. However, research on development of a vaccine against S. agalactiae mastitis is scarce. The aims of the present study were to: (1) develop a single-dose vaccine against S. agalactiae based on poly(lactic-co-glycolic acid) (PLGA) microspheres (MS) encapsulated CAMP factor, a conserved virulent protein encoded by S. agalactiae's cfb gene; and (2) evaluate its immunogenicity and protective efficacy in a mouse model. The cfb gene was cloned and expressed in a recombinant Escherichia coli strain Trans1-T1. The CAMP factor was tested to determine a safe dose range and then encapsulated in MS of PLGA (50:50) to assess its release pattern in vitro and immune reaction in vivo. Furthermore, a mouse model and a histopathological assay were developed to evaluate bacterial burden and vaccine efficacy. In the low dosage range (S. agalactiae challenge. Additionally, no pathological lesions were detected in the vaccinated group. Therefore, PLGA-CAMP conferred protective efficacy against S. agalactiae in our mouse model, indicating its potential as a vaccine against S. agalactiae mastitis. Furthermore, the slow-release kinetics of PLGA MS warranted optimism for development of a single-dose vaccine. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production.

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Vasilyeva, Anastasia; Santos Sanches, Ilda; Florindo, Carlos; Dmitriev, Alexander

2015-01-01

Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level. Inactivation of bgrR abrogated bac gene expression and increased virulence properties of S. agalactiae. In this study, a total of 140 strains were screened for the presence of bac gene, and the TCS bgrR and bgrS genes. A total of 53 strains carried the bac, bgrR and bgrS genes. Most of them (48 strains) expressed β antigen, while five strains did not express β antigen. Three strains, in which bac gene sequence was intact, while bgrR and/or bgrS genes had mutations, and expression of β antigen was absent, were complemented with a constructed plasmid pBgrRS(P) encoding functionally active bgrR and bgrS gene alleles. This procedure restored expression of β antigen indicating the crucial regulatory role of TCS BgrRS. The complemented strain A49V/BgrRS demonstrated attenuated virulence in intraperitoneal mice model of S. agalactiae infection compared to parental strain A49V. In conclusion we showed that disruption of β antigen expression is associated with: i) insertion of ISSa4 upstream the bac gene just after the ribosomal binding site; ii) point mutation G342A resulting a stop codon TGA within the bac gene and a truncated form of β antigen; iii) single deletion (G) in position 439 of the bgrR gene resulting in a frameshift and the loss of DNA-binding domain of the BgrR protein, and iv) single base substitutions in bgrR and bgrS genes causing single amino acid substitutions in BgrR (Arg187Lys) and BgrS (Arg252Gln). The fact that BgrRS negatively controls virulent properties of S. agalactiae gives a novel clue for understanding of S

Latent class analysis of real time qPCR and bacteriological culturing for the diagnosis of Streptococcus agalactiae in cow composite milk samples

DEFF Research Database (Denmark)

Holmøy, Ingrid H.; Toft, Nils; Jørgensen, Hannah J.

2018-01-01

Streptococcus agalactiae (S. agalactiae) has re-emerged as a mastitis pathogen among Norwegian dairy cows. The Norwegian cattle health services recommend that infected herds implement measures to eradicate S. agalactiae, this includes a screening of milk samples from all lactating cows....... The performance of the qPCR-test currently in use for this purpose has not been evaluated under field conditions. The objective of this study was to estimate the sensitivity and specificity of the real-time qPCR assay in use in Norway (Mastitis 4 qPCR, DNA Diagnostics A/S, Risskov, Denmark) and compare...... it to conventional bacteriological culturing for detection of S. agalactiae in milk samples. Because none of these tests are considered a perfect reference test, the evaluation was performed using latent class models in a Bayesian analysis. Aseptically collected cow-composite milk samples from 578 cows belonging...

An homolog of the Frz Phosphoenolpyruvate:carbohydrate phosphoTransferase System of extraintestinal pathogenic Escherichia coli is encoded on a genomic island in specific lineages of Streptococcus agalactiae.

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Patron, Kévin; Gilot, Philippe; Camiade, Emilie; Mereghetti, Laurent

2015-06-01

We identified a Streptococcus agalactiae metabolic region (fru2) coding for a Phosphoenolpyruvate:carbohydrate phosphoTransferase System (PTS) homologous to the Frz system of extraintestinal pathogenic Escherichia coli strains. The Frz system is involved in environmental sensing and regulation of the expression of adaptation and virulence genes in E. coli. The S. agalactiae fru2 region codes three subunits of a PTS transporter of the fructose-mannitol family, a transcriptional activator of PTSs of the MtlR family, an allulose-6 phosphate-3-epimerase, a transaldolase and a transketolase. We demonstrated that all these genes form an operon. The fru2 operon is present in a 17494-bp genomic island. We analyzed by multilocus sequence typing a population of 492 strains representative of the S. agalactiae population and we showed that the presence of the fru2 operon is linked to the phylogeny of S. agalactiae. The fru2 operon is always present within strains of clonal complexes CC 1, CC 7, CC 10, CC 283 and singletons ST 130 and ST 288, but never found in other CCs and STs. Our results indicate that the fru2 operon was acquired during the evolution of the S. agalactiae species from a common ancestor before the divergence of CC 1, CC 7, CC 10, CC 283, ST 130 and ST 288. As S. agalactiae strains of CC 1 and CC 10 are frequently isolated from adults with invasive disease, we hypothesize that the S. agalactiae Fru2 system senses the environment to allow the bacterium to adapt to new conditions encountered during the infection of adults. Copyright © 2015 Elsevier B.V. All rights reserved.

Bacterial Protein Characterization of Streptococcus agalactiae by SDS-page Method for Subclinical Mastitis Irradiated Vaccine Materials in Dairy Cattle

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Tuasikal, B.J.; Wibawan, I.W.T.; Pasaribu, F.H; Estuningsih, S.

2012-01-01

A study have been conducted to isolate and characterize bacterial protein S. agalactiae, which is antigenic and can be used to test immunogenicity of vaccine in order to manufacture irradiated mastitis (inflammation of the udder) vaccine in ruminant. The study aims to determine the Molecular Weight (MW) bacterial protein S. agalactiae irradiation, which can be used to test the nature of its antigenic caharacteristic. The character of S. agalactiae antigenic stimulates antibody induction of the immune system, in which case is the body's defense system against mastitis disease in cattle. In this study, irradiation of gamma ray is used to attenuate the pathogenicity of bacteria by reducing S. agalactiae antigenic characteristic. Previous research, in irradiation dose orientation before antigenic protein isolation of S. agalactiae, indicated that irradiation lethal dose to 50% (LD 50 ) is 17 Gy. The characterization of S. agalactiae bacteria isolate using SDS-page method results in no significance different between irradiated and non-irradiated group, which indicated by MW range 75 - 100 kDa base on marker standard which used, or 99 kDa by the linier equation of Y = 11,60 - 0.05X (where Y = bands distance; X = MW standard protein); r 2 = 0.99. In conclusion, 17 Gy irradiation dose does not impair antigenic property of S. agalactiae and therefore, can be applied to produce base material of irradiated vaccine for mastitis. (author)

Development of a quantitative PCR assay for monitoring Streptococcus agalactiae colonization and tissue tropism in experimentally infected tilapia.

Science.gov (United States)

Su, Y-L; Feng, J; Li, Y-W; Bai, J-S; Li, A-X

2016-02-01

Streptococcus agalactiae has become one of the most important emerging pathogens in the aquaculture industry and has resulted in large economic losses for tilapia farms in China. In this study, three pairs of specific primers were designed and tested for their specificities and sensitivities in quantitative real-time polymerase chain reactions (qPCRs) after optimization of the annealing temperature. The primer pair IGS-s/IGS-a, which targets the 16S-23S rRNA intergenic spacer region, was finally chosen, having a detection limit of 8.6 copies of S. agalactiae DNA in a 20 μL reaction mixture. Bacterial tissue tropism was demonstrated by qPCR in Oreochromis niloticus 5 days post-injection with a virulent S. agalactiae strain. Bacterial loads were detected at the highest level in brain, followed by moderately high levels in kidney, heart, spleen, intestines, and eye. Significantly lower bacterial loads were observed in muscle, gill and liver. In addition, significantly lower bacterial loads were observed in the brain of convalescent O. niloticus 14 days post-injection with several different S. agalactiae strains. The qPCR for the detection of S. agalactiae developed in this study provides a quantitative tool for investigating bacterial tissue tropism in infected fish, as well as for monitoring bacterial colonization in convalescent fish. © 2015 John Wiley & Sons Ltd.

Structural Differences between the Streptococcus agalactiae Housekeeping and Pilus-Specific Sortases: SrtA and SrtC1

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Khare, B.; Krishnan, V.; Rajashankar, K.R.; I-Hsiu, H.; Xin, M.; Ton-That, H.; Narayana, S.V. (Texas-HSC); (Cornell); (UAB)

2011-10-21

The assembly of pili on the cell wall of Gram-positive bacteria requires transpeptidase enzymes called sortases. In Streptococcus agalactiae, the PI-1 pilus island of strain 2603V/R encodes two pilus-specific sortases (SrtC1 and SrtC2) and three pilins (GBS80, GBS52 and GBS104). Although either pilus-specific sortase is sufficient for the polymerization of the major pilin, GBS80, incorporation of the minor pilins GBS52 and GBS104 into the pilus structure requires SrtC1 and SrtC2, respectively. The S. agalactiae housekeeping sortase, SrtA, whose gene is present at a different location and does not catalyze pilus polymerization, was shown to be involved in cell wall anchoring of pilus polymers. To understand the structural basis of sortases involved in such diverse functions, we determined the crystal structures of S. agalactiae SrtC1 and SrtA. Both enzymes are made of an eight-stranded beta-barrel core with variations in their active site architecture. SrtA exhibits a catalytic triad arrangement similar to that in Streptococcus pyogenes SrtA but different from that in Staphylococcus aureus SrtA. In contrast, the SrtC1 enzyme contains an N-terminal helical domain and a 'lid' in its putative active site, which is similar to that seen in Streptococcus pneumoniae pilus-specific sortases, although with subtle differences in positioning and composition. To understand the effect of such differences on substrate recognition, we have also determined the crystal structure of a SrtC1 mutant, in which the conserved DP(W/F/Y) motif was replaced with the sorting signal motif of GBS80, IPNTG. By comparing the structures of WT wild type SrtA and SrtC1 and the 'lid' mutant of SrtC1, we propose that structural elements within the active site and the lid may be important for defining the role of specific sortase in pili biogenesis.

Structural differences between the Streptococcus agalactiae housekeeping and pilus-specific sortases: SrtA and SrtC1.

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B Khare

Full Text Available The assembly of pili on the cell wall of Gram-positive bacteria requires transpeptidase enzymes called sortases. In Streptococcus agalactiae, the PI-1 pilus island of strain 2603V/R encodes two pilus-specific sortases (SrtC1 and SrtC2 and three pilins (GBS80, GBS52 and GBS104. Although either pilus-specific sortase is sufficient for the polymerization of the major pilin, GBS80, incorporation of the minor pilins GBS52 and GBS104 into the pilus structure requires SrtC1 and SrtC2, respectively. The S. agalactiae housekeeping sortase, SrtA, whose gene is present at a different location and does not catalyze pilus polymerization, was shown to be involved in cell wall anchoring of pilus polymers. To understand the structural basis of sortases involved in such diverse functions, we determined the crystal structures of S. agalactiae SrtC1 and SrtA. Both enzymes are made of an eight-stranded beta-barrel core with variations in their active site architecture. SrtA exhibits a catalytic triad arrangement similar to that in Streptococcus pyogenes SrtA but different from that in Staphylococcus aureus SrtA. In contrast, the SrtC1 enzyme contains an N-terminal helical domain and a 'lid' in its putative active site, which is similar to that seen in Streptococcus pneumoniae pilus-specific sortases, although with subtle differences in positioning and composition. To understand the effect of such differences on substrate recognition, we have also determined the crystal structure of a SrtC1 mutant, in which the conserved DP(W/F/Y motif was replaced with the sorting signal motif of GBS80, IPNTG. By comparing the structures of WT wild type SrtA and SrtC1 and the 'lid' mutant of SrtC1, we propose that structural elements within the active site and the lid may be important for defining the role of specific sortase in pili biogenesis.

A novel one-step real-time multiplex PCR assay to detect Streptococcus agalactiae presence and serotypes Ia, Ib, and III.

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Furfaro, Lucy L; Chang, Barbara J; Payne, Matthew S

2017-09-01

Streptococcus agalactiae is the leading cause of early-onset neonatal sepsis. Culture-based screening methods lack the sensitivity of molecular assays and do not indicate serotype; a potentially important virulence marker. We aimed to develop a multiplex PCR to detect S. agalactiae while simultaneously identifying serotypes Ia, Ib, and III; commonly associated with infant disease. Primers were designed to target S. agalactiae serotype-specific cps genes and the dltS gene. The assay was validated with 512 vaginal specimens from pregnant women. 112 (21.9%) were dltS positive, with 14.3%, 0.9%, and 6.3% of these identified as cps Ia, Ib, and III, respectively. Our assay is a specific and sensitive method to simultaneously detect S. agalactiae and serotypes Ia, Ib, and III in a single step. It is of high significance for clinical diagnostic applications and also provides epidemiological data on serotype, information that may be important for vaccine development and other targeted non-antibiotic therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

Optimización de metodologías de cribaje para la búsqueda de Streptococcus agalactiae en embarazadas Optimization of screening methodologies for the detection of Streptococcus agalactiae in pregnant women

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Silvia E. Montibello

2011-03-01

Full Text Available Streptococcus agalactiae es una causa importante de morbimortalidad en mujeres embarazadas y neonatos en todo el mundo. El objetivo del presente trabajo fue determinar la utilidad del medio cromogénico chromID Strepto B de bioMérieux para detectar S. agalactiae en embarazadas cuando la muestra es sembrada directamente en dicho medio o después del enriquecimiento en caldo de Todd Hewitt selectivo, opciones que se compararon con la metodología propuesta por el CDC . Se analizaron 1924 hisopados, 962 de introito vaginal y 962 rectales, correspondientes a 962 embarazadas entre la semana 35 y 37 de gestación, asistidas en distintos hospitales. Los hisopados se sembraron directamente en el medio chromID Strepto B (CR y luego se colocaron en un caldo de Todd Hewitt selectivo, suplementado con 15 µg/ml de ácido nalidíxico y 10 µg/ml de colistina (CTH-sel. Luego de 24 h de incubación, se realizaron subcultivos en el medio CR y en agar con 5% de sangre de carnero (ASO. La prevalencia global de S. agalactiae fue de 17,4%. La sensibilidad, la especificidad y los valores predictivos positivo y negativo del subcultivo en CR del material desarrollado en el CTH -sel fueron 98,8%, 100%, 100% y 99,7% respectivamente, con una incubación de 48 h. Los valores correspondientes de la siembra directa fueron 57,8%, 100%, 100% y 90%. La sensibilidad del subcultivo en ASO del material desarrollado en el CTH -sel fue del 85%. Se destaca el excelente rendimiento del subcultivo en CR luego del enriquecimiento en caldo de Todd Hewitt selectivo en comparación con el método propuesto por el CDC.Streptococcus agalactiae is a significant worldwide cause of morbidity and mortality in pregnant women and their newborn infants. The objective of this work was to determine the usefulness of bioMrieux chromogenic medium chromID Strepto B (CR for detecting S. agalactiae in pregnant women from the selective Todd-Hewitt broth (sel-THB against the methods proposed by the CDC

Additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae and S. agalactiae capsular type Ib: is genetic resistance correlated?

Science.gov (United States)

Streptococcus (S.) iniae and S. agalactiae are both economically important Gram positive bacterial pathogens affecting the globally farmed tilapia (Oreochromis spp.). Historically control of these bacteria in tilapia culture has included biosecurity, therapeutants and vaccination strategies. Genet...

Effect of carryover and presampling procedures on the results of real-time PCR used for diagnosis of bovine intramammary infections with Streptococcus agalactiae at routine milk recordings

DEFF Research Database (Denmark)

Mahmmod, Yasser; Mweu, Marshal Mutinda; Nielsen, Søren Saxmose

2014-01-01

with Streptococcus agalactiae (S. agalactiae) in dairy herds with conventional milking parlours. Misclassification may result in unnecessary costs for treatment and culling. The objectives of this study were to (1) determine the effect of carryover on PCR-positivity for S. agalactiae at different PCR cycle threshold...... (Ct) cut-offs by estimating the between-cow correlation while accounting for the milking order, and (2) evaluate the effect of aseptic presampling procedures (PSP) on PCR-positivity at the different Ct-value cut-offs. The study was conducted in four herds with conventional milking parlours at routine...

The effects of fish gender on susceptibility to acute Streptococcus agalactiae infection in Javanese medaka Oryzias javanicus.

Science.gov (United States)

Amal, M N A; Zarif, S T; Suhaiba, M S; Aidil, M R M; Shaqinah, N N; Zamri-Saad, M; Ismail, A

2017-12-05

This study describes the susceptibility of different fish gender following acute Streptococcus agalactiae infection by using Javanese medaka Oryzias javanicus as test fish. The fish were grouped into four groups, which were: (1) all-male; (2) all-female; (3) mixed-gender (1 male: 1 female ratio); and (4) control non-infected (1 male: 1 female ratio). The fish in group 1, 2 and 3 were intraperitoneally exposed to 5.4 × 10 8  CFU/mL of S. agalactiae, while for group 4, the fish were exposed using sterile broth. The main clinical signs and histopathological changes of infected Javanese medaka were commonly observed in S. agalactiae infected fishes. However, no difference on clinical signs and histopathological changes of fish in group 1, 2 and 3 were noticed. The Javanese medaka mortality in group 1, 2 and 3 were observed from 4 h post infection (hpi) to 6 hpi, with the cumulative mortality from 3% to 30%. Then, the mortality increased at 12 hpi, with the range from 53% to 80%. However, 100% of the infected fish dead at 24 hpi. No clinical sign, histopathological change and fish mortality recorded in group 4. Generally, the clinical signs, mortality patterns, cumulative mortality and histopathological changes of Javanese medaka infected by S. agalactiae did not show any difference between the all-male, all-female and mixed-gender groups. This indicates that the susceptibility of fish to S. agalactiae infection is not influenced by their gender. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of fish gender on susceptibility to acute Streptococcus agalactiae infection in Javanese medaka Oryzias javanicus.

Science.gov (United States)

Amal, M N A; Zarif, S T; Suhaiba, M; Aidil, M R M; Shaqinah, N N; Zamri-Saad, M; Ismail, A

2017-12-04

This study describes the susceptibility of different fish gender following acute Streptococcus agalactiae infection by using Javanese medaka Oryzias javanicus as test fish. The fish were grouped into four groups, which were: (1) all-male; (2) all-female; (3) mixed-gender (1 male: 1 female ratio); and (4) control non-infected (1 male: 1 female ratio). The fish in group 1, 2 and 3 were intraperitoneally exposed to 5.4 × 10 8  CFU/ml of S. agalactiae, while for group 4, the fish were exposed using sterile broth. The main clinical signs and histopathological changes of infected Javanese medaka were commonly observed in S. agalactiae infected fishes. However, no difference on clinical signs and histopathological changes of fish in group 1, 2 and 3 were noticed. The Javanese medaka mortality in group 1, 2 and 3 were observed from 4 h post infection (hpi) to 6 hpi, with the cumulative mortality from 3% to 30%. Then, the mortality increased at 12 hpi, with the range from 53% to 80%. However, 100% of the infected fish dead at 24 hpi. No clinical signs, histopathological changes and fish mortality recorded in group 4. Generally, the clinical signs, mortality patterns, cumulative mortality and histopathological changes of Javanese medaka infected by S. agalactiae did not show any difference between the all-male, all-female and mixed-gender groups. This indicates that the susceptibility of fish to S. agalactiae infection is not influenced by their gender. Copyright © 2017. Published by Elsevier Ltd.

Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions

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Krishnan, Vengadesan [UNESCO Regional Centre for Biotechnology (RCB), Gurgaon 122 016, Haryana (India); Dwivedi, Prabhat [University of Texas Health Science Center, Houston, TX 77030 (United States); Kim, Brandon J. [San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States); Samal, Alexandra; Macon, Kevin [University of Alabama at Birmingham, Birmingham, AL 35294 (United States); Ma, Xin; Mishra, Arunima [University of Texas Health Science Center, Houston, TX 77030 (United States); Doran, Kelly S. [San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States); Ton-That, Hung [University of Texas Health Science Center, Houston, TX 77030 (United States); Narayana, Sthanam V. L., E-mail: narayana@uab.edu [University of Alabama at Birmingham, Birmingham, AL 35294 (United States); UNESCO Regional Centre for Biotechnology (RCB), Gurgaon 122 016, Haryana (India)

2013-06-01

The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. In addition, a homology model of the remaining two domains of GBS104 was built and a model of full-length GBS104 was generated by combining the homology model (the N1 and N4 domains) and the crystal structure of the 75 kDa fragment (the N2 and N3 domains). This rod-shaped GBS104 model is constructed of three IgG-like domains (the N1, N2 and N4 domains) and one vWFA-like domain (the N3 domain). The N1 and N2 domains of GBS104 are assembled with distinct and remote segments contributed by the N- and C-termini. The metal-binding site in the N3 domain of GBS104 is in the closed/low-affinity conformation. Interestingly, this domain hosts two long arms that project away from the metal-binding site. Using site-directed mutagenesis, two cysteine residues that lock the N3 domain of GBS104 into the open/high-affinity conformation were introduced. Both wild-type and disulfide-locked recombinant proteins were tested for binding to extracellular matrix proteins such as collagen, fibronectin, fibrinogen and laminin, and an increase in fibronectin binding affinity was identified for the disulfide-locked N3 domain, suggesting that induced conformational changes may play a possible role in receptor binding.

Structure of Streptococcus agalactiae tip pilin GBS104: a model for GBS pili assembly and host interactions

International Nuclear Information System (INIS)

Krishnan, Vengadesan; Dwivedi, Prabhat; Kim, Brandon J.; Samal, Alexandra; Macon, Kevin; Ma, Xin; Mishra, Arunima; Doran, Kelly S.; Ton-That, Hung; Narayana, Sthanam V. L.

2013-01-01

The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. The crystal structure of a 75 kDa central fragment of GBS104, a tip pilin from the 2063V/R strain of Streptococcus agalactiae (group B streptococcus; GBS), is reported. In addition, a homology model of the remaining two domains of GBS104 was built and a model of full-length GBS104 was generated by combining the homology model (the N1 and N4 domains) and the crystal structure of the 75 kDa fragment (the N2 and N3 domains). This rod-shaped GBS104 model is constructed of three IgG-like domains (the N1, N2 and N4 domains) and one vWFA-like domain (the N3 domain). The N1 and N2 domains of GBS104 are assembled with distinct and remote segments contributed by the N- and C-termini. The metal-binding site in the N3 domain of GBS104 is in the closed/low-affinity conformation. Interestingly, this domain hosts two long arms that project away from the metal-binding site. Using site-directed mutagenesis, two cysteine residues that lock the N3 domain of GBS104 into the open/high-affinity conformation were introduced. Both wild-type and disulfide-locked recombinant proteins were tested for binding to extracellular matrix proteins such as collagen, fibronectin, fibrinogen and laminin, and an increase in fibronectin binding affinity was identified for the disulfide-locked N3 domain, suggesting that induced conformational changes may play a possible role in receptor binding

Quantitative assessment of the blood-brain barrier opening caused by Streptococcus agalactiae hyaluronidase in a BALB/c mouse model.

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Luo, Su; Cao, Qing; Ma, Ke; Wang, Zhaofei; Liu, Guangjin; Lu, Chengping; Liu, Yongjie

2017-10-19

Streptococcus agalactiae is a pathogen causing meningitis in animals and humans. However, little is known about the entry of S. agalactiae into brain tissue. In this study, we developed a BALB/c mouse model based on the intravenous injection of β-galactosidase-positive Escherichia coli M5 as an indicator of blood-brain barrier (BBB) opening. Under physiological conditions, the BBB is impermeable to E. coli M5. In pathological conditions caused by S. agalactiae, E. coli M5 is capable of penetrating the brain through a disrupted BBB. The level of BBB opening can be assessed by quantitative measurement of E. coli M5 loads per gram of brain tissue. Further, we used the model to evaluate the role of S. agalactiae hyaluronidase in BBB opening. The inactivation of hylB gene encoding a hyaluronidase, HylB, resulted in significantly decreased E. coli M5 colonization, and the intravenous injection of purified HylB protein induced BBB opening in a dose-dependent manner. This finding verified the direct role of HylB in BBB invasion and traversal, and further demonstrated the practicability of the in vivo mouse model established in this study. This model will help to understand the S. agalactiae-host interactions that are involved in this bacterial traversal of the BBB and to develop efficacious strategies to prevent central nervous system infections.

The Efficacy of Nile Tilapia (Oreochromis niloticus Broodstock and Larval Immunization against Streptococcus agalactiae and Aeromonas hydrophila

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Wesly Pasaribu

2018-03-01

Full Text Available Streptococcus agalactiae and Aeromonas hydrophila have been recognized as the causative agents of mortality in tilapia larvae with single infection and coinfection. The objective of this study was to evaluate the efficacy of maternal transfer and offspring protection from the immunization of monovalent and bivalent vaccines on Nile tilapia (Oreochromis niloticus broodstock and larval immunization. Four groups of broodstock were intraperitoneally injected with formalin killed whole-cells of S. agalactiae (Sa group, A. hydrophila (Ah group, the bivalent mixed vaccine of them (Biv group, and phosphate-buffered saline as a control (Pbs group. Immunization of the larvae produced from immunized broodstock with a bivalent vaccine (Biv1 group and Pbs (Pbs1 group was performed by immersion at 20 days after hatch. Larvae produced from the Pbs group were unvaccinated as the control (Pbs2 group. Changes in the specific antibody and relative percent survival were measured. The Sa and Ah groups that could increase specific antibodies and protection against pathogenic bacteria were challenged with the homologous bacteria. The Biv group stimulated and protected against both S. agalactiae and A. hydrophila. The specific antibody of the Biv1 group was higher than the Pbs1 and Pbs2 groups. The last observation in this study showed that the relative percent survival of the Biv group after challenged S. agalactiae, A. hydrophila, and coinfection were 74.74 ± 3.18%, 73.81 ± 8.58%, and 71.48 ± 5.70%, respectively. The use of bivalent vaccines on the broodstock and larvae may be a strategy to reduce mortality in Nile tilapia larvae caused by single pathogen infection of S. agalactiae and A. hydrophila, or coinfection with both S. agalactiae and A. hydrophila.

In vitro characterization of PlySK1249, a novel phage lysin, and assessment of its antibacterial activity in a mouse model of Streptococcus agalactiae bacteremia.

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Oechslin, Frank; Daraspe, Jean; Giddey, Marlyse; Moreillon, Philippe; Resch, Grégory

2013-12-01

Beta-hemolytic Streptococcus agalactiae is the leading cause of bacteremia and invasive infections. These diseases are treated with β-lactams or macrolides, but the emergence of less susceptible and even fully resistant strains is a cause for concern. New bacteriophage lysins could be promising alternatives against such organisms. They hydrolyze the bacterial peptidoglycan at the end of the phage cycle, in order to release the phage progeny. By using a bioinformatic approach to screen several beta-hemolytic streptococci, a gene coding for a lysin was identified on a prophage carried by Streptococcus dysgalactiae subsp. equisimilis SK1249. The gene product, named PlySK1249, harbored an original three-domain structure with a central cell wall-binding domain surrounded by an N-terminal amidase and a C-terminal CHAP domain. Purified PlySK1249 was highly lytic and bactericidal for S. dysgalactiae (2-log10 CFU/ml decrease within 15 min). Moreover, it also efficiently killed S. agalactiae (1.5-log10 CFU/ml decrease within 15 min) but not several streptococcal commensal species. We further investigated the activity of PlySK1249 in a mouse model of S. agalactiae bacteremia. Eighty percent of the animals (n = 10) challenged intraperitoneally with 10(6) CFU of S. agalactiae died within 72 h, whereas repeated injections of PlySK1249 (45 mg/kg 3 times within 24 h) significantly protected the mice (P S. dysgalactiae, demonstrated high cross-lytic activity against S. agalactiae both in vitro and in vivo. These encouraging results indicated that PlySK1249 might represent a good candidate to be developed as a new enzybiotic for the treatment of systemic S. agalactiae infections.

In silico analysis of candidate proteins sharing homology with Streptococcus agalactiae proteins and their role in male infertility.

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Parida, Rajeshwari; Samanta, Luna

2017-02-01

Leukocytospermia is a physiologic condition defined as human semen with a leukocyte count of >1 x 10 6 cells/ml that is often correlated with male infertility. Moreover, bacteriospermia has been associated with leukocytospermia ultimately leading to male infertility. We have found that semen samples with >1 x 10 6 /ml leukocytes and/or bacteriospermia have oxidative predominance as evidenced by augmented protein carbonyl and lipid peroxidation status of the semen which is implicated in sperm dysfunction. It has been reported that Streptococcus agalactiae is present in bacteriospermic samples. Previous research has shown that human leukocyte antigen beta chain paralog (HLA-DRB) alleles interact best with the infected sperm cells rather than the non-infected cells. Little is known about the interaction of major histocompatibility complex (MHC) present on leukocytes with the sperm upon bacterial infection and how it induces an immunological response which we have addressed by epitope mapping. Therefore, we examined MHC class II derived bacterial peptides which might have human sperm-related functional aspects. Twenty-two S. agalactiae proteins were obtained from PUBMED protein database for our study. Protein sequences with more than two accession numbers were aligned using CLUSTAL Omega to check their conservation pattern. Each protein sequence was then analyzed for T-cell epitope prediction against HLA-DRB alleles using the immune epitope database (IEDB) analysis tool. Out of a plethora of peptides obtained from this analysis, peptides corresponding to proteins of interest such as DNA binding response regulator, hyaluronate lyase and laminin binding protein were screened against the human proteome using Blastp. Interestingly, we have found bacterial peptides sharing homology with human peptides deciphering some of the important sperm functions. Antibodies raised against these probable bacterial antigens of fertility will not only help us understand the mechanism of

NATURAL MUTATION IN THE GENE OF RESPONSE REGULATOR BgrR RESULTING IN REPRESSION OF Bac PROTEIN SYNTHESIS, A PATHOGENICITY FACTOR OF STREPTOCOCCUS AGALACTIAE

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A. S. Rozhdestvenskaya

2013-01-01

Full Text Available Abstract. Streptococcus agalactiae can cause variety of diseases of newborns and adults. For successful colonization of different human tissues and organs as well as for suppression of the host immune system S. agalactiae expresses numerous virulence factors. For coordinated expression of the virulence genes S. agalactiae employs regulatory molecules including regulatory proteins of two-component systems. Results of the present study demonstrated that in S. agalactiae strain A49V the natural mutation in the brgR gene encoding for BgrR regulatory protein, which is component of regulatory system BgrRS, resulted in the repression of Bac protein synthesis, a virulence factor of S. agalactiae. A single nucleotide deletion in the bgrR gene has caused a shift of the reading frame and the changes in the primary, secondary and tertiary structures of the BgrR protein. The loss of functional activity of BgrR protein in A49V strain and repression of Bac protein synthesis have increased virulence of the strain in experimental animal streptococcal infection.

Identificação dos sorotipos de Streptococcus agalactiae pela técnica de PCR de amostras isoladas em pacientes colonizados e infectados na cidade de Campinas e região

OpenAIRE

Katelí Fiolo

2011-01-01

Resumo: Streptococcus agalactiae, conhecido como Estreptococo beta-hemolítico do grupo B (EGB), é classificado por diferenças capsulares que podem variar em dez sorotipos, alguns responsáveis por infecções materno-infantis sérias e debilitantes ou podendo ainda levar ao óbito. O EGB pode ocasionar também, infecções graves em adultos e idosos. OBJETIVO: Descrever e analisar o perfil epidemiológico dos sorotipos prevalentes de Streptococcus agalactiae, provenientes de infecção em recém-nascidos...

Analysis of the type II-A CRISPR-Cas system of Streptococcus agalactiae reveals distinctive features according to genetic lineages

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Lier, Clément; Baticle, Elodie; Horvath, Philippe; Haguenoer, Eve; Valentin, Anne-Sophie; Glaser, Philippe; Mereghetti, Laurent; Lanotte, Philippe

2015-01-01

CRISPR-Cas systems (clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins) are found in 90% of archaea and about 40% of bacteria. In this original system, CRISPR arrays comprise short, almost unique sequences called spacers that are interspersed with conserved palindromic repeats. These systems play a role in adaptive immunity and participate to fight non-self DNA such as integrative and conjugative elements, plasmids, and phages. In Streptococcus agalactiae, a bacterium implicated in colonization and infections in humans since the 1960s, two CRISPR-Cas systems have been described. A type II-A system, characterized by proteins Cas9, Cas1, Cas2, and Csn2, is ubiquitous, and a type I–C system, with the Cas8c signature protein, is present in about 20% of the isolates. Unlike type I–C, which appears to be non-functional, type II-A appears fully functional. Here we studied type II-A CRISPR-cas loci from 126 human isolates of S. agalactiae belonging to different clonal complexes that represent the diversity of the species and that have been implicated in colonization or infection. The CRISPR-cas locus was analyzed both at spacer and repeat levels. Major distinctive features were identified according to the phylogenetic lineages previously defined by multilocus sequence typing, especially for the sequence type (ST) 17, which is considered hypervirulent. Among other idiosyncrasies, ST-17 shows a significantly lower number of spacers in comparison with other lineages. This characteristic could reflect the peculiar virulence or colonization specificities of this lineage. PMID:26124774

Crystallization and preliminary crystallographic analysis of two Streptococcus agalactiae proteins: the family II inorganic pyrophosphatase and the serine/threonine phosphatase

International Nuclear Information System (INIS)

Rantanen, Mika K.; Lehtiö, Lari; Rajagopal, Lakshmi; Rubens, Craig E.; Goldman, Adrian

2006-01-01

Two S. agalactiae proteins, the inorganic pyrophosphatase and the serine/threonine phosphatase, were crystallized and diffraction data were collected and processed from these crystals. The data from the two protein crystals extended to 2.80 and 2.65 Å, respectively. Streptococcus agalactiae, which infects human neonates and causes sepsis and meningitis, has recently been shown to possess a eukaryotic-like serine/threonine protein phosphorylation signalling cascade. Through their target proteins, the S. agalactiae Ser/Thr kinase and Ser/Thr phosphatase together control the growth as well as the morphology and virulence of this organism. One of the targets is the S. agalactiae family II inorganic pyrophosphatase. The inorganic pyrophosphatase and the serine/threonine phosphatase have therefore been purified and crystallized and diffraction data have been collected from their crystals. The data were processed using XDS. The inorganic pyrosphosphatase crystals diffracted to 2.80 Å and the Ser/Thr phosphatase crystals to 2.65 Å. Initial structure-solution experiments indicate that structure solution will be successful in both cases. Solving the structure of the proteins involved in this cascade is the first step towards understanding this phenomenon in atomic detail

Crystallization and preliminary crystallographic analysis of two Streptococcus agalactiae proteins: the family II inorganic pyrophosphatase and the serine/threonine phosphatase

Energy Technology Data Exchange (ETDEWEB)

Rantanen, Mika K.; Lehtiö, Lari [Institute of Biotechnology, University of Helsinki, PO Box 65, FIN-00014, Helsinki (Finland); Rajagopal, Lakshmi; Rubens, Craig E. [Division of Infectious Disease, Children’s Hospital and Regional Medical Center, Seattle, Washington 98105 (United States); Goldman, Adrian, E-mail: adrian.goldman@helsinki.fi [Institute of Biotechnology, University of Helsinki, PO Box 65, FIN-00014, Helsinki (Finland)

2006-09-01

Two S. agalactiae proteins, the inorganic pyrophosphatase and the serine/threonine phosphatase, were crystallized and diffraction data were collected and processed from these crystals. The data from the two protein crystals extended to 2.80 and 2.65 Å, respectively. Streptococcus agalactiae, which infects human neonates and causes sepsis and meningitis, has recently been shown to possess a eukaryotic-like serine/threonine protein phosphorylation signalling cascade. Through their target proteins, the S. agalactiae Ser/Thr kinase and Ser/Thr phosphatase together control the growth as well as the morphology and virulence of this organism. One of the targets is the S. agalactiae family II inorganic pyrophosphatase. The inorganic pyrophosphatase and the serine/threonine phosphatase have therefore been purified and crystallized and diffraction data have been collected from their crystals. The data were processed using XDS. The inorganic pyrosphosphatase crystals diffracted to 2.80 Å and the Ser/Thr phosphatase crystals to 2.65 Å. Initial structure-solution experiments indicate that structure solution will be successful in both cases. Solving the structure of the proteins involved in this cascade is the first step towards understanding this phenomenon in atomic detail.

Influência da temperatura na infecção de tilápias do Nilo por Streptococcus agalactiae

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Paulo Fernandes Marcusso

2015-04-01

Full Text Available Mudanças ambientais afetam a homeostase dos peixes, tornando-os mais suscetíveis a doenças. No Brasil, tem sido relatados surtos de infecção por Streptococcus agalactiae em tilápia do Nilo, principalmente quando se encontram fora da zona de conforto térmico. No presente trabalho, foi avaliada a taxa de mortalidade e determinado quais foram os órgãos mais afetados por essa bactéria em temperaturas que ocorrem naturalmente no Sul do Brasil. Quarenta tilápias-do-nilo (Oreochromis niloticus foram infectadas por Streptococcus agalactiae e distribuídas em quatro grupos (n = 10, cada um deles submetidos a diferentes temperaturas: G1: 24°C, G2: 26°C, G3: 28°C e G4: 32°C. Os peixes foram monitorados durante 10 dias. Os peixes com sinais clínicos irreversíveis foram sacrificados e coletadas amostras de cérebro, fígado e rins para analise bacteriológica e molecular. Foram observados sinais compatíveis com infecção estreptocócica em todos os grupos. A taxa de mortalidade mais elevada ocorreu nos grupos mantidos nas temperaturas de 24°C e 32°C. O cérebro foi o órgão mais afetado, com a maior percentagem de isolamento de S. agalactiae pelos dois métodos de diagnostico. Os resultados sugerem que, tal como nos mamíferos, temperaturas que estão mais afastadas da zona de conforto afetam significativamente a homeostase dos peixes, aumentando a sua susceptibilidade para infecções bacterianas.

Role of the serine-rich surface glycoprotein Srr1 of Streptococcus agalactiae in the pathogenesis of infective endocarditis.

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Ho Seong Seo

Full Text Available The binding of bacteria to fibrinogen and platelets are important events in the pathogenesis of infective endocarditis. Srr1 is a serine-rich repeat glycoprotein of Streptococcus agalactiae that binds directly to the Aα chain of human fibrinogen. To assess the impact of Srr1 on the pathogenesis of endocarditis due to S. agalactiae, we first examined the binding of this organism to immobilized human platelets. Strains expressing Srr1 had significantly higher levels of binding to human platelets in vitro, as compared with isogenic Δsrr1 mutants. In addition, platelet binding was inhibited by pretreatment with anti-fibrinogen IgG or purified Srr1 binding region. To assess the contribution of Srr1 to pathogenicity, we compared the relative virulence of S. agalactiae NCTC 10/84 strain and its Δsrr1 mutant in a rat model of endocarditis, where animals were co-infected with the WT and the mutant strains at a 1:1 ratio. At 72 h post-infection, bacterial densities (CFU/g of the WT strain within vegetations, kidneys, and spleens were significantly higher, as compared with the Δsrr1 mutant. These results indicate that Srr1 contributes to the pathogenesis of endocarditis due to S. agalactiae, at least in part through its role in fibrinogen-mediated platelet binding.

Spatiotemporal patterns, annual baseline and movement-related incidence of Streptococcus agalactiae infection in Danish dairy herds: 2000-2009.

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Mweu, Marshal M; Nielsen, Søren S; Halasa, Tariq; Toft, Nils

2014-02-01

Several decades after the inception of the five-point plan for the control of contagious mastitis pathogens, Streptococcus agalactiae (S. agalactiae) persists as a fundamental threat to the dairy industry in many countries. A better understanding of the relative importance of within- and between-herd sources of new herd infections coupled with the spatiotemporal distribution of the infection, may aid in effective targeting of control efforts. Thus, the objectives of this study were: (1) to describe the spatiotemporal patterns of infection with S. agalactiae in the population of Danish dairy herds from 2000 to 2009 and (2) to estimate the annual herd-level baseline and movement-related incidence risks of S. agalactiae infection over the 10-year period. The analysis involved registry data on bacteriological culture of all bulk tank milk samples collected as part of the mandatory Danish S. agalactiae surveillance scheme as well as live cattle movements into dairy herds during the specified 10-year period. The results indicated that the predicted risk of a herd becoming infected with S. agalactiae varied spatiotemporally; the risk being more homogeneous and higher in the period after 2005. Additionally, the annual baseline risks yielded significant yet distinctive patterns before and after 2005 - the risk of infection being higher in the latter phase. On the contrary, the annual movement-related risks revealed a non-significant pattern over the 10-year period. There was neither evidence for spatial clustering of cases relative to the population of herds at risk nor spatial dependency between herds. Nevertheless, the results signal a need to beef up within-herd biosecurity in order to reduce the risk of new herd infections. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of Isolates of Streptococcus agalactiae from Diseased Farmed and Wild Marine Fish from the U.S. Gulf Coast, Latin America, and Thailand.

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Soto, Esteban; Wang, Rui; Wiles, Judy; Baumgartner, Wes; Green, Christopher; Plumb, John; Hawke, John

2015-06-01

We examined Lancefield serogroup B Streptococcus isolates recovered from diseased, cultured hybrid Striped Bass (Striped Bass Morone saxatilis × White Bass M. chrysops) and wild and cultured Gulf Killifish Fundulus grandis from coastal waters of the U.S. Gulf of Mexico (Gulf coast) and compared those isolates to strains from tilapias Oreochromis spp. reared in Mississippi, Thailand, Ecuador, and Honduras and to the original Gulf coast strain identified by Plumb et al. ( 1974 ). The isolates were subjected to phylogenetic, biochemical, and antibiotic susceptibility analyses. Genetic analysis was performed using partial sequence comparison of (1) the 16S ribosomal RNA (rRNA) gene; (2) the sipA gene, which encodes a surface immunogenic protein; (3) the cspA gene, which encodes a cell surface-associated protein; and (4) the secY gene, which encodes components of a general protein secretion pathway. Phylogenies inferred from sipA, secY, and cspA gene sequence comparisons were more discriminating than that inferred from the 16S rRNA gene sequence comparison. The U.S. Gulf coast strains showed a high degree of similarity to strains from South America and Central America and belonged to a unique group that can be distinguished from other group B streptococci. In agreement with the molecular findings, biochemical and antimicrobial resistance analyses demonstrated that the isolates recovered from the U.S. Gulf coast and Latin America were more similar to each other than to isolates from Thailand. Three laboratory challenge methods for inducing streptococcosis in Gulf Killifish were evaluated-intraperitoneal (IP) injection, immersion (IMM), and immersion plus abrasion (IMMA)-using serial dilutions of S. agalactiae isolate LADL 97-151, a representative U.S. Gulf coast strain. The dose that was lethal to 50% of test fish by 14 d postchallenge was approximately 2 CFU/fish via IP injection. In contrast, the fish that were challenged via IMM or IMMA presented cumulative mortality

Whole genome shotgun sequencing of Indian strains of Streptococcus agalactiae

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Balaji Veeraraghavan

2017-12-01

Full Text Available Group B streptococcus is known as a leading cause of neonatal infections in developing countries. The present study describes the whole genome shotgun sequences of four Group B Streptococcus (GBS isolates. Molecular data on clonality is lacking for GBS in India. The present genome report will add important information on the scarce genome data of GBS and will help in deriving comparative genome studies of GBS isolates at global level. This Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank under the accession numbers NHPL00000000 – NHPO00000000.

Construction of a Streptococcus agalactiae phoB mutant and evaluation of its potential as an attenuated modified live vaccine in golden pompano, Trachinotus ovatus.

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Cai, Xiaohui; Wang, Bei; Peng, Yinhui; Li, Yuan; Lu, Yishan; Huang, Yucong; Jian, Jichang; Wu, Zaohe

2017-04-01

Streptococcus agalactiae is a Gram-positive pathogen that can survive inside professional phagocytes and nonphagocytic cells to cause septicemia and meningoencephalitis in freshwater and marine fish. However, vaccines based on extracellular products (ECP) and formalin-killed whole S. agalactiae cells, as well as subunit vaccine are unable to protect fish from infection by variant serotypes S. agalactiae. The search for live attenuated vaccine with highly conserved and virulent-related genes is essential for producing a vaccine to help understand and control streptococcosis In this study, the phoB gene was cloned from pathogenic S. agalactiae TOS01 strain and the mutant strain SAΔphoB was constructed via allelic exchange mutagenesis. The results showed that the deduced amino acid of S. agalactiae TOS01 shares high similarities with other Streptococcus spp. and has high conserved response regulator receiver domain (REC) and DNA-binding effector domain of two-component system response regulators (Trans_reg_C). Cell adherence and invasion assays, challenge experiments and histopathological changes post-vaccination were performed and observed, the results showed that the mutant strain SAΔphoB has a lower adherence and invasion rate and less virulent than the wild type strain in golden pompano, and it doesn't induce clinical symptoms and obvious pathological changes in golden pompano, thereby indicating that the deletion of phoB affects the virulence and infectious capacity of S. agalactiae. Golden pompano vaccinated via intraperitoneal injection SAΔphoB had the relative percent survival value of 93.1% after challenge with TOS01, demonstrating its high potential as an effective attenuated live vaccine candidate. Real-time PCR assays showed that the SAΔphoB was able to enhance the expression of immune-related genes, including MHC-I, MyD88, IL-22 and IL-10 after vaccination, indicating that the SAΔphoB is able to induce humoral and cell-mediated immune response

Molecular and functional characterization of CD59 from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

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Gan, Zhen; Wang, Bei; Zhou, Wei; Lu, Yishan; Zhu, Weiwei; Tang, Jufen; Jian, JiChang; Wu, Zaohe

2015-05-01

CD59, the major inhibitor of membrane attack complex, plays a crucial role in regulation of complement activation. In this paper, a CD59 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD59) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for complement-inhibitory activity were detected in the deduced amino acid sequence of On-CD59. In healthy Nile tilapia, the On-CD59 transcripts could be detected in all the examined tissues, with the most abundant expression in the brain. When immunized with inactivated S. agalactiae, there was a clear time-dependent expression pattern of On-CD59 in the skin, brain, head kidney, thymus and spleen, with quite different kinetic expressions. The assays for the complement-inhibitory activity suggested that recombinant On-CD59 protein had a species-selective inhibition of complement. Moreover, our works showed that recombinant On-CD59 protein may possess both binding activities to PGN and LTA and inhibiting activity of S. agalactiae. These findings indicated that On-CD59 may play important roles in the immune response to S. agalactiae in Nile tilapia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Survey of immunological features of the alpha-like proteins of Streptococcus agalactiae.

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Maeland, Johan A; Afset, Jan E; Lyng, Randi V; Radtke, Andreas

2015-02-01

Nearly all Streptococcus agalactiae (group B streptococcus [GBS]) strains express a protein which belongs to the so-called alpha-like proteins (Alps), of which Cα, Alp1, Alp2, Alp3, Rib, and Alp4 are known to occur in GBS. The Alps are chimeras which form mosaic structures on the GBS surface. Both N- and C-terminal stretches of the Alps possess immunogenic sites of dissimilar immunological specificity. In this review, we have compiled data dealing with the specificity of the N- and C-terminal immunogenic sites of the Alps. The majority of N-terminal sites show protein specificity while the C-terminal sites show broader cross-reactivity. Molecular serotyping has revealed that antibody-based serotyping has often resulted in erroneous Alp identification, due to persistence of cross-reacting antibodies in antisera for serotyping. Retrospectively, this could be expected on the basis of sequence analysis results. Some of the historical R proteins are in fact Alps. The data included in the review may provide a basis for decisions regarding techniques for the preparation of specific antisera for serotyping of GBS, for use in other approaches in GBS research, and for decision making in the context of GBS vaccine developments. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Reactive oxygen species generation mediated by NADPH oxidase and PI3K/Akt pathways contribute to invasion of Streptococcus agalactiae in human endothelial cells.

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Oliveira, Jessica Silva Santos de; Santos, Gabriela da Silva; Moraes, João Alfredo; Saliba, Alessandra Mattos; Barja-Fidalgo, Thereza Christina; Mattos-Guaraldi, Ana Luíza; Nagao, Prescilla Emy

2018-01-01

BACKGROUND Streptococcus agalactiae can causes sepsis, pneumonia, and meningitis in neonates, the elderly, and immunocompromised patients. Although the virulence properties of S. agalactiae have been partially elucidated, the molecular mechanisms related to reactive oxygen species (ROS) generation in infected human endothelial cells need further investigation. OBJECTIVES This study aimed to evaluate the influence of oxidative stress in human umbilical vein endothelial cells (HUVECs) during S. agalactiae infection. METHODS ROS production during S. agalactiae-HUVEC infection was detected using the probe CM-H2DCFDA. Microfilaments labelled with phalloidin-FITC and p47phox-Alexa 546 conjugated were analysed by immunofluorescence. mRNA levels of p47phox (NADPH oxidase subunit) were assessed using Real Time qRT-PCR. The adherence and intracellular viability of S. agalactiae in HUVECs with or without pre-treatment of DPI, apocynin (NADPH oxidase inhibitors), and LY294002 (PI3K inhibitor) were evaluated by penicillin/gentamicin exclusion. Phosphorylation of p47phox and Akt activation by S. agalactiae were evaluated by immunoblotting analysis. FINDINGS Data showed increased ROS production 15 min after HUVEC infection. Real-Time qRT-PCR and western blotting performed in HUVEC infected with S. agalactiae detected alterations in mRNA levels and activation of p47phox. Pre-treatment of endothelial cells with NADPH oxidase (DPI and apocynin) and PI3K/Akt pathway (LY294002) inhibitors reduced ROS production, bacterial intracellular viability, and generation of actin stress fibres in HUVECs infected with S. agalactiae. CONCLUSIONS ROS generation via the NADPH oxidase pathway contributes to invasion of S. agalactiae in human endothelial cells accompanied by cytoskeletal reorganisation through the PI3K/Akt pathway, which provides novel evidence for the involvement of oxidative stress in S. agalactiae pathogenesis.

Effect of Eugenol against Streptococcus agalactiae and Synergistic Interaction with Biologically Produced Silver Nanoparticles

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Renata Perugini Biasi-Garbin

2015-01-01

Full Text Available Streptococcus agalactiae (group B streptococci (GBS is an important infections agent in newborns associated with maternal vaginal colonization. Intrapartum antibiotic prophylaxis in GBS-colonized pregnant women has led to a significant reduction in the incidence of early neonatal infection in various geographic regions. However, this strategy may lead to resistance selecting among GBS, indicating the need for new alternatives to prevent bacterial transmission and even to treat GBS infections. This study reported for the first time the effect of eugenol on GBS isolated from colonized women, alone and in combination with silver nanoparticles produced by Fusarium oxysporum (AgNPbio. Eugenol showed a bactericidal effect against planktonic cells of all GBS strains, and this effect appeared to be time-dependent as judged by the time-kill curves and viability analysis. Combination of eugenol with AgNPbio resulted in a strong synergistic activity, significantly reducing the minimum inhibitory concentration values of both compounds. Scanning and transmission electron microscopy revealed fragmented cells and changes in bacterial morphology after incubation with eugenol. In addition, eugenol inhibited the viability of sessile cells during biofilm formation and in mature biofilms. These results indicate the potential of eugenol as an alternative for controlling GBS infections.

Cinética de fermentación y acción antimicrobiana de Weissella confusa contra Staphylococcus aureus y Streptococcus agalactiae

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Liliana Serna Cock

2010-01-01

Full Text Available Se evaluaron las cinéticas de producción de biomasa, producción de ácido láctico, consumo de sustrato y actividad antimicrobiana de Weissella confusa, una bacteria acido láctica con actividad antimicrobiana frente a Streptococcus agalactiae y Staphylococcus aureus, microorganismos productores de mastitis bovina. Las fermentaciones se llevaron a cabo anaeróbicamente en discontinuo utilizando como sustratos, sustrato comercial (SC, leche suplementada con extracto levadura (LEL y leche suplementada con extracto de levadura y glucosa (LELG y se compararon los parámetros cinéticos. La mayor inhibición de los patógenos, la mayor producción de ácido láctico y el mayor rendimiento de biomasa se presentó en sustrato LELG. En éste último sustrato al cabo de la cuarta hora de fermentación, se presentó un diámetro de inhibición de 36,33 mm para Staphylococcus aureus y a la octava hora de fermentación 39 mm de diámetro para Streptococcus agalactiae; la producción máxima de ácido láctico fue 13,12 gL-1 (a las 48 h y la máxima concentración de biomasa fue 3,07 gL-1 (a las 48 h. Estos resultados fueron superiores a los obtenidos en SC donde, para el mismo tiempo de fermentación, se obtuvieron 24,38 mm para Staphylococcus aureus y 30,58 mm de diámetro de inhibición para Streptococcus agalactiae; la mayor producción de ácido láctico fue 11,6 gL-1 (a las 12 h y la mayor concentración de biomasa fue 1,18 gL-1 (a las 24 h. Los resultados sugieren que el LELG puede convertirse en una alternativa a bajo costo para la producción de Weissella confusa, microorganismo con gran potencial para el control y el tratamiento de mastitis bovina.

An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus).

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Munang'andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

2016-12-13

Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia ( Niloticus oreochromis ) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy.

An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus)

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Munang’andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

2016-01-01

Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy. PMID:27983591

Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae.

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Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Astushi

2016-09-08

BACKGROUND Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). CASE REPORT A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our emergency room with fever and loss of appetite, which had lasted for 5 days. On admission, results of serologic tests pointed to severe infection. Electrocardiography showed normal sinus rhythm with first-degree atrioventricular block and incomplete right bundle branch block, and transthoracic echocardiography and transesophageal echocardiography revealed severe mitral regurgitation caused by posterior leaflet perforation and 2 vegetations (5 mm and 6 mm) on the tricuspid valve. The patient was initially treated with ceftriaxone and gentamycin because blood and cutaneous ulcer cultures yielded S. agalactiae. On hospital day 2, however, sudden CAVB requiring transvenous pacing occurred, and the patient's heart failure and infection worsened. Although an emergent surgery is strongly recommended, even in patients with uncontrolled heart failure or infection, surgery was not performed because of the Child-Pugh class B liver cirrhosis. Despite intensive therapy, the patient's condition further deteriorated, and he died on hospital day 16. On postmortem examination, a 2×1-cm vegetation was seen on the perforated posterior mitral leaflet, and the infection had extended to the interventricular septum. Histologic examination revealed extensive necrosis of the AV node. CONCLUSIONS This rare case of CAVB resulting from S. agalactiae IE points to the fact that in monitoring patients with IE involving the mitral valve, clinicians should be aware of the potential for perivalvular extension of the infection, which can lead to fatal heart block.

Gene Regulation in Streptococcus pneumoniae: interplay between nutrition and virulence

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W.T. Hendriksen (Wouter)

2010-01-01

textabstractStreptococcus pneumoniae (the pneumococcus) is a Gram-positive bacterium, which belongs to the species of streptococci. Other pathogenic bacteria belonging to this class include Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus suis, Streptococcus uberis, Streptococcus

Organization of the capsule biosynthesis gene locus of the oral streptococcus Streptococcus anginosus.

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Tsunashima, Hiroyuki; Miyake, Katsuhide; Motono, Makoto; Iijima, Shinji

2012-03-01

The capsular polysaccharide (CPS) of the important oral streptococcus Streptococcus anginosus, which causes endocarditis, and the genes for its synthesis have not been clarified. In this study, we investigated the gene locus required for CPS synthesis in S. anginosus. Southern hybridization using the cpsE gene of the well-characterized bacterium S. agalactiae revealed that there is a similar gene in the genome of S. anginosus. By using the colony hybridization technique and inverse PCR, we isolated the CPS synthesis (cps) genes of S. anginosus. This gene cluster consisted of genes containing typical regulatory genes, cpsA-D, and glycosyltransferase genes coding for glucose, rhamnose, N-acetylgalactosamine, and galactofuranose transferases. Furthermore, we confirmed that the cps locus is required for CPS synthesis using a mutant strain with a defective cpsE gene. The cps cluster was found to be located downstream the nrdG gene, which encodes ribonucleoside triphosphate reductase activator, as is the case in other oral streptococci such as S. gordonii and S. sanguinis. However, the location of the gene cluster was different from those of S. pneumonia and S. agalactiae. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Remodeling of the Streptococcus agalactiae transcriptome in response to growth temperature.

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Laurent Mereghetti

Full Text Available BACKGROUND: To act as a commensal bacterium and a pathogen in humans and animals, Streptococcus agalactiae (group B streptococcus, GBS must be able to monitor and adapt to different environmental conditions. Temperature variation is a one of the most commonly encountered variables. METHODOLOGY/PRINCIPAL FINDINGS: To understand the extent to which GBS modify gene expression in response to temperatures encountered in the various hosts, we conducted a whole genome transcriptome analysis of organisms grown at 30 degrees C and 40 degrees C. We identified extensive transcriptome remodeling at various stages of growth, especially in the stationary phase (significant transcript changes occurred for 25% of the genes. A large proportion of genes involved in metabolism was up-regulated at 30 degrees C in stationary phase. Conversely, genes up-regulated at 40 degrees C relative to 30 degrees C include those encoding virulence factors such as hemolysins and extracellular secreted proteins with LPXTG motifs. Over-expression of hemolysins was linked to larger zones of hemolysis and enhanced hemolytic activity at 40 degrees C. A key theme identified by our study was that genes involved in purine metabolism and iron acquisition were significantly up-regulated at 40 degrees C. CONCLUSION/SIGNIFICANCE: Growth of GBS in vitro at different temperatures resulted in extensive remodeling of the transcriptome, including genes encoding proven and putative virulence genes. The data provide extensive new leads for molecular pathogenesis research.

Isolation and identification of Mycoplasma agalactiae by culture and polymerase chain reaction (PCR from sheep of Qom province, Iran

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Abtin, A.R.

2013-05-01

Full Text Available Contagious agalactia (C.A is an infectious syndrome of sheep that is characterized by mastitis andsubsequent failure of milk production, arthritis, abortion and keratoconjunctivitis. Mycoplasma agalactiae(M. agalactiae is the main cause of the disease in sheep. The aim of this study was isolation andidentification of M. agalactiae with culture and polymerase chain reaction (PCR assay from sheep of Qomprovince in Iran. A total of 102 samples were collected from milk secretion, eye, ear and joint exudates ofsheep. All samples were cultured in PPLO broth supplemented for M. agalaciae isolation. The bacteriaDNAs were extracted by phenol/chloroform method and the PCR assay was applied for detecting ofMycoplasma genus in 163bp fragment of 16S rRNA gene and M. agalactiae in 375bp fragment oflipoprotein gene from culture as same as in clinical samples. Out of the 102 samples, 19(18.63% cultureswere shown positive and typical Mycoplasma colonies in PPLO agar culture diagnostic method and59(57.8% were scored positive by Mycoplasma genus PCR, 19(18.62% of the samples were scoredpositive by using M. agalactiae PCR as diagnostic method. Out of the 102 samples, 19 samples wereshown both positive in the culture and PCR, 42 samples were shown both negative in the culture and PCR.40 samples were negative in the culture and positive in PCR whereas only one sample was positive inculture and negative in PCR. The results showed that the more isolations of M. agalactiae were taken from milk and less in joint samples. M. agalactiae was one of the main factors of contagious agalactia that was detected for the first time from sheep in Qom province.

Effect of Excoecaria agallocha on non-specific immune responses and disease resistance of Oreochromis niloticus against Streptococcus agalactiae.

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Laith, A A; Mazlan, A G; Effendy, A W; Ambak, M A; Nurhafizah, W W I; Alia, A S; Jabar, A; Najiah, M

2017-06-01

The current study was designed to evaluate the effects of Excoecaria agallocha leaf extracts on immune mechanisms and resistance of tilapia, Oreochromis niloticus, after challenge with Streptococcus agalactiae. Fish were divided into 6 groups; groups 1-5 fed with E. agallocha leaf extracts at 10, 20, 30, 40 and 50mgkg -1 level, respectively. Group 6 were fed without extract addition and acted as control. E. agallocha extracts were administered as feed supplement in fish diet for 28days and the hematological, immunological, and growth performance studies were conducted. Fish were infected with S. agalactiae at a dose of 15×105CFUmL -1 and the total white blood cell (WBC), phagocytosis and respiratory burst activities of leukocytes, serum bactericidal activity, lysozyme, total protein, albumin, and globulin levels were monitored and mortalities recorded for 15days post infection. Results revealed that feeding O. niloticus with 50mgkg -1 of E. agallocha enhanced WBC, phagocytic, respiratory burst, serum bactericidal and lysozyme activities on day 28 pre-challenge and on 3rd, 6th, 9th, 12th and 15th day post-challenge as compared to control. Total protein and albumin were not enhanced by E. agallocha diet. E. agallocha increased the survival of fish after challenge with S. agalactiae. The highest mortality rate (97%) was observed in control fish and the lowest mortality (27%) was observed with group fed with 50mgkg -1 extract. The results indicate that dietary intake of E. agallocha methanolic leaf extract in O. niloticus enhances the non-specific immunity and disease resistance against S. agalactiae pathogen. Copyright © 2017. Published by Elsevier Ltd.

Regulation of PI-2b Pilus Expression in Hypervirulent Streptococcus agalactiae ST-17 BM110.

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Bruno Périchon

Full Text Available The widely spread Streptococcus agalactiae (also known as Group B Streptococcus, GBS "hypervirulent" ST17 clone is strongly associated with neonatal meningitis. The PI-2b locus is mainly found in ST17 strains but is also present in a few non ST17 human isolates such as the ST-7 prototype strain A909. Here, we analysed the expression of the PI-2b pilus in the ST17 strain BM110 as compared to the non ST17 A909. Comparative genome analyses revealed the presence of a 43-base pair (bp hairpin-like structure in the upstream region of PI-2b operon in all 26 ST17 genomes, which was absent in the 8 non-ST17 strains carrying the PI-2b locus. Deletion of this 43-bp sequence in strain BM110 resulted in a 3- to 5-fold increased transcription of PI-2b. Characterization of PI-2b promoter region in A909 and BM110 strains was carried out by RNAseq, primer extension, qRT-PCR and transcriptional fusions with gfp as reporter gene. Our results indicate the presence of a single promoter (Ppi2b with a transcriptional start site (TSS mapped 37 bases upstream of the start codon of the first PI-2b gene. The large operon of 16 genes located upstream of PI-2b codes for the group B carbohydrate (also known as antigen B, a major constituent of the bacterial cell wall. We showed that the hairpin sequence located between antigen B and PI-2b operons is a transcriptional terminator. In A909, increased expression of PI-2b probably results from read-through transcription from antigen B operon. In addition, we showed that an extended 5' promoter region is required for maximal transcription of gfp as a reporter gene in S. agalactiae from Ppi2b promoter. Gene reporter assays performed in Lactococcus lactis strain NZ9000, a related non-pathogenic Gram-positive species, revealed that GBS-specific regulatory factors are required to drive PI-2b transcription. PI-2b expression is up-regulated in the BM110ΔcovR mutant as compared to the parental BM110 strain, but this effect is probably

RovS and its associated signaling peptide form a cell-to-cell communication system required for Streptococcus agalactiae pathogenesis.

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Pérez-Pascual, David; Gaudu, Philippe; Fleuchot, Betty; Besset, Colette; Rosinski-Chupin, Isabelle; Guillot, Alain; Monnet, Véronique; Gardan, Rozenn

2015-01-20

Bacteria can communicate with each other to coordinate their biological functions at the population level. In a previous study, we described a cell-to-cell communication system in streptococci that involves a transcriptional regulator belonging to the Rgg family and short hydrophobic peptides (SHPs) that act as signaling molecules. Streptococcus agalactiae, an opportunistic pathogenic bacterium responsible for fatal infections in neonates and immunocompromised adults, has one copy of the shp/rgg locus. The SHP-associated Rgg is called RovS in S. agalactiae. In this study, we found that the SHP/RovS cell-to-cell communication system is active in the strain NEM316 of S. agalactiae, and we identified different partners that are involved in this system, such as the Eep peptidase, the PptAB, and the OppA1-F oligopeptide transporters. We also identified a new target gene controlled by this system and reexamined the regulation of a previously proposed target gene, fbsA, in the context of the SHP-associated RovS system. Furthermore, our results are the first to indicate the SHP/RovS system specificity to host liver and spleen using a murine model, which demonstrates its implication in streptococci virulence. Finally, we observed that SHP/RovS regulation influences S. agalactiae's ability to adhere to and invade HepG2 hepatic cells. Hence, the SHP/RovS cell-to-cell communication system appears to be an essential mechanism that regulates pathogenicity in S. agalactiae and represents an attractive target for the development of new therapeutic strategies. Rgg regulators and their cognate pheromones, called small hydrophobic peptides (SHPs), are present in nearly all streptococcal species. The general pathways of the cell-to-cell communication system in which Rgg and SHP take part are well understood. However, many other players remain unidentified, and the direct targets of the system, as well as its link to virulence, remain unclear. Here, we identified the different players

Laboratory-controlled Challenges of Nile Tilapia (Oreochromis niloticus) with Streptococcus agalactiae: Comparisons between Immersion, Oral, Intracoelomic and Intramuscular Routes of Infection.

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Soto, E; Zayas, M; Tobar, J; Illanes, O; Yount, S; Francis, S; Dennis, M M

2016-11-01

Streptococcus agalactiae, the aetiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. To gain a better understanding of the pathogenesis of streptococcosis in Nile tilapia (Oreochromis niloticus), and to identify the experimental route of infection that most closely mimics natural disease, fingerlings were challenged with S. agalactiae utilizing different delivery methods. Fingerlings were challenged via intracoelomic injection (ICinj), intramuscular injection (IMinj), orally or by immersion with serial dilutions of S. agalactiae. The dose lethal to 50% of test fish 15 days post challenge was 120 colony forming units (CFU)/fish after ICinj, and 10 5  CFU/fish after IMinj. Acute mortalities were present in both groups, but were higher in the fish challenged by ICinj. Very low mortalities were observed in the fish challenged via oral or immersion routes. Post-mortem evaluation of survivors revealed classical lesions associated with fish streptococcosis, including granulomatous or lymphohistiocytic epicarditis, splenitis, meningitis, myocarditis, choroiditis and exophthalmia. The information obtained improves our understanding of the pathogenesis of streptococcosis in fish, and provides useful information regarding controlled experimental infections in tilapia challenged with S. agalactiae. Results from this study suggest that IMinj challenge methods are not only suitable to induce streptococcosis in tilapia, but they may be the preferred method to study the pathogenesis of the naturally-occurring disease in this species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Caracterização Genética da Resistência à Eritromicina em Streptococcus agalactia e Degestantes saudáveis

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Pinheiro, Sandra Marisa de Oliveira Sequeira

2009-01-01

Dissertação de Mestrado em Biologia Clínica Laboratorial Streptococcus agalactiae (Grupo B de Lancefield, EGB), um microrganismo comensal do homem, reconhecido em 1920 como o agente etiológico da mastite bovina, tem sido associado a infecções em parturientes e recém-nascidos, sendo o principal agente de septicemia e meningite neonatal. Para evitar a infecção perinatal recomenda-se a pesquisa da bactéria na região vagino-perianal durante o terceiro semestre de gravidez, indicando o tratamen...

Isolation and identification of Mycoplasma agalactiae by culture and Polymerase Chain Reaction in Sheep and Goat Milk Samples in Kordestan province, Iran

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Khaki, P.

2011-06-01

Full Text Available Contagious agalactiae (C.A. is one of the most common disease affecting small ruminants which is caused by Mycoplasma agalactiae. This disease is particularly widespread around the world and Iran is one of the countries that C.A. is present. The aim of this study was isolation and identification of M. agalactiae (MG with culture and PCR technique in milk samples in Kordestan province, Iran. A total of 367 milk samples were collected from sheep and goat. Specific published primers amplify a 375 bp gene of MG were used for PCR. Twenty (5.5% out of 367 were positive in PPLO agar and 5 (25% out of these isolates were positive with Mycoplasma agalactiae primers. Four (75% out of 5 isolates was from sheep and 1(25% from goat. Result of PCR with 367 milk samples showed that 11(3% of them were positive with these primers. The isolation of M. agalactiae showed that C.A is present in Kordestan province and our results suggested that PCR method because of reduces the time consuming could be an alternative method beside culture.

A metabolomic investigation into the effects of temperature on Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus) based on UPLC-MS/MS.

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Hu, Wen-Ting; Guo, Wei-Liang; Meng, Ai-Yun; Sun, Yun; Wang, Shi-Feng; Xie, Zhen-Yu; Zhou, Yong-Can; He, Chaozu

2017-10-01

Streptococcosis caused by Streptococcus agalactiae is one of the most serious diseases in farmed tilapia, and temperature is one of the most important environmental factors related to its outbreak. To elucidate the influence of temperature variation on the pathogen from a metabolic perspective, the global metabolomics of 2 pathogenic strains of S. agalactiae from sick tilapia were analyzed at 35°C and 25°C using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with pattern recognition approaches and pathway analysis. The result showed that the metabolic status of S. agalactiae was extensively affected by its culture temperature. Based on the results of metabolites contributing to these differences, a large number of nucleotides and their ramifications were markedly elevated at 35°C. Various energy substances, components of the cell wall and substances associated with stress regulation such as glyceraldehyde 3-phosphate, pyroglutamic acid, glutamate, d-Alanyl-d-alanine, glycerophosphocholine, dephospho-CoA, and oxidized glutathione increased when the strains were cultured at 35°C. Additionally, a general decrease in various precursors of capsule, antigen, and virulence protein formation were detected including mannose, maltotriose, N-acetyl-d-glucosamine 6-phosphate, uracil, proline, and citrulline. These metabolic changes indicated that metabolic activity decreased, while adaptive ability to environment and pathogenicity to host increased at high temperature. This study is the first to determine the metabolomic responses of S. agalactiae to temperature, and the results are useful to reveal its pathogenic mechanism and find effective disease control. Copyright © 2017 Elsevier B.V. All rights reserved.

Antimicrobial Resistance Profiles of Bacteria Isolated from the Nasal Cavity of Camels in Samburu, Nakuru, and Isiolo Counties of Kenya

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J. M. Mutua

2017-01-01

Full Text Available This study was designed to determine antimicrobial resistance profiles of bacteria isolated from the nasal cavity of healthy camels. A total of 255 nasal samples (swabs were collected in Isiolo, Samburu, and Nakuru counties, Kenya, from which 404 bacterial isolates belonging to various genera and species were recovered. The bacterial isolates included Bacillus (39.60%, coagulase-negative Staphylococcus (29.95%, Streptococcus species other than Streptococcus agalactiae (25.74%, coagulase-positive Staphylococcus (3.96%, and Streptococcus agalactiae (0.74%. Isolates were most susceptible to Gentamicin (95.8%, followed by Tetracycline (90.5%, Kanamycin and Chloramphenicol (each at 85.3%, Sulphamethoxazole (84.2%, Co-trimoxazole (82.1%, Ampicillin (78.9%, and finally Streptomycin (76.8%. This translated to low resistance levels. Multidrug resistance was also reported in 30.5% of the isolates tested. Even though the antibiotic resistance demonstrated in this study is low, the observation is significant, since the few resistant normal flora could be harboring resistance genes which can be transferred to pathogenic bacteria within the animal, to other animals’ bacteria and, most seriously, to human pathogens.

Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

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Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

2016-07-01

PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia. Copyright © 2016 Elsevier Ltd. All rights reserved.

The β-hemolysin and intracellular survival of Streptococcus agalactiae in human macrophages.

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Sagar, Anubha; Klemm, Carolin; Hartjes, Lara; Mauerer, Stefanie; van Zandbergen, Ger; Spellerberg, Barbara

2013-01-01

S. agalactiae (group B streptococci, GBS) is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cell line and human granulocytes were infected with a serotype Ia S. agalactiae wild type strain and its isogenic nonhemolytic mutant. We could show that the nonhemolytic mutants were able to survive in significantly higher numbers than the hemolytic wild type strain, in THP-1 macrophage-like cells and in assays with human granulocytes. Intracellular bacterial multiplication, however, could not be observed. The hemolytic wild type strain stimulated a significantly higher release of Tumor Necrosis Factor-α than the nonhemolytic mutant in THP-1 cells, while similar levels of the chemokine Interleukin-8 were induced. In order to investigate bacterial mediators of IL-8 release in this setting, purified cell wall preparations from both strains were tested and found to exert a potent proinflammatory stimulus on THP-1 cells. In conclusion, our results indicate that the β-hemolysin has a strong influence on the intracellular survival of S. agalactiae and that a tightly controlled regulation of β-hemolysin expression is required for the successful establishment of S. agalactiae in different host niches.

Evaluation of the efficacy of intramuscular versus intramammary treatment of subclinical Streptococcus agalactiae mastitis in dairy cows in Colombia.

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Reyes, J; Chaffer, M; Sanchez, J; Torres, G; Macias, D; Jaramillo, M; Duque, P C; Ceballos, A; Keefe, G P

2015-08-01

A randomized controlled trial was performed in 17 Colombian dairy herds to determine the cure risk among cows subclinically infected with Streptococcus agalactiae exposed to 2 antibiotic therapies. Composite milk samples were collected before milking at the onset of the trial (pretreatment) and 2 subsequent times over a period of approximately 63 d. The intramammary application (IMM) of ampicillin-cloxacillin was compared with the intramuscular application (IM) of penethamate hydriodide, and cure risks after an initial and retreatment application were assessed. Cure risk after the initial treatment was higher (82.4%) for the IMM treatment than for IM therapy (65.8%). However, no difference was observed in the cure risk of refractory cases after retreatment (IMM=52.6% vs. IM=51.2%). The cumulative cure risk (both initial and retreatment) was 90.4 and 82.9% for the IMM and IM products, respectively. A 2-level random effects logistic model that controlled for pretreatment cow-level somatic cell count, indicated that IM treatment (odds ratio=0.37) had a lower cure risk than IMM and a tendency for a lower cure risk with increasing baseline somatic cell count. Our findings suggest that both products and administration routes can reduce the prevalence of S. agalactiae in affected herds, but the IMM product had a better efficacy in curing the infection. In addition to the treatment protocol, the cow somatic cell count should be considered when making management decisions for cows infected with S. agalactiae. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Molecular mapping of the cell wall polysaccharides of the human pathogen Streptococcus agalactiae

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Beaussart, Audrey; Péchoux, Christine; Trieu-Cuot, Patrick; Hols, Pascal; Mistou, Michel-Yves; Dufrêne, Yves F.

2014-11-01

The surface of many bacterial pathogens is covered with polysaccharides that play important roles in mediating pathogen-host interactions. In Streptococcus agalactiae, the capsular polysaccharide (CPS) is recognized as a major virulence factor while the group B carbohydrate (GBC) is crucial for peptidoglycan biosynthesis and cell division. Despite the important roles of CPS and GBC, there is little information available on the molecular organization of these glycopolymers on the cell surface. Here, we use atomic force microscopy (AFM) and transmission electron microscopy (TEM) to analyze the nanoscale distribution of CPS and GBC in wild-type (WT) and mutant strains of S. agalactiae. TEM analyses reveal that in WT bacteria, peptidoglycan is covered with a very thin (few nm) layer of GBC (the ``pellicle'') overlaid by a 15-45 nm thick layer of CPS (the ``capsule''). AFM-based single-molecule mapping with specific antibody probes shows that CPS is exposed on WT cells, while it is hardly detected on mutant cells impaired in CPS production (ΔcpsE mutant). By contrast, both TEM and AFM show that CPS is over-expressed in mutant cells altered in GBC expression (ΔgbcO mutant), indicating that the production of the two surface glycopolymers is coordinated in WT cells. In addition, AFM topographic imaging and molecular mapping with specific lectin probes demonstrate that removal of CPS (ΔcpsE), but not of GBC (ΔgbcO), leads to the exposure of peptidoglycan, organized into 25 nm wide bands running parallel to the septum. These results indicate that CPS forms a homogeneous barrier protecting the underlying peptidoglycan from environmental exposure, while the presence of GBC does not prevent peptidoglycan detection. This work shows that single-molecule AFM, combined with high-resolution TEM, represents a powerful platform for analysing the molecular arrangement of the cell wall polymers of bacterial pathogens.

Growth, immune responses and protection of Nile tilapia Oreochromis niloticus immunized with formalin-killed Streptococcus agalactiae serotype Ia and III vaccines

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Atchariya Suwannasang

2017-08-01

Full Text Available The protective efficacy of formalin-killed Streptococcus agalactiae (Group B Streptococcus, GBS serotype Ia (GBS-Ia and III (GBS-III vaccines were assessed in Nile tilapia (Oreochromis niloticus. The fish with an average weight of 34.45± 0.08 g were immunized by intraperitoneal (i.p. injection with 4 different formalin-killed vaccines prepared from GBS-Ia (1x1010 CFU/mL, GBS-III (1x1010 CFU/mL, and combined GBS-Ia and GBS-III in an equal volume at final concentrations 1x1010 CFU/mL and 2x1010 CFU/mL in comparison with the non-immunized control group. At 2 and 4 weeks post vaccination, no significant differences were observed (p>0.05 among treatments in growth performance or haemato-immunological parameters, except the increased red blood cell at 2 weeks. Significantly increased antibody titers (p<0.05 against GBS-Ia and GBS-III antigens were noted in the groups immunized with homologous GBS vaccines, whereas the group reacted with heterologous GBS antigen showed less antibody titer as compared with the control group. The vaccination experiment indicated that i.p. injection of Nile tilapia with formalin-killed cells prepared from GBS-Ia or GBS-III provides significant protection, with relative percent survival (RPS value of 52.17 to 71.42%, against a challenge with the homologous serotype isolate, whereas the RPS in fish challenged with a heterologous serotype isolate varied from 20.00 to 53.57%. These results suggested that vaccines from either GBS-Ia or GBS-III have insufficient cross-protective efficacy against the other serotypes. However, a mixed vaccine produced from both GBS serotypes Ia and III provided significant protection with 65.00 to 95.66% RPS which could be an excellent vaccine to protect fish against streptococcosis caused by both GBS serotypes Ia and III.

Human milk oligosaccharides inhibit growth of group B Streptococcus

NARCIS (Netherlands)

Lin, Ann E; Autran, Chloe A; Szyszka, Alexandra; Escajadillo, Tamara; Huang, Mia; Godula, Kamil; Prudden, Anthony R; Boons, Geert-Jan; Lewis, Amanda L; Doran, Kelly S; Nizet, Victor; Bode, Lars

2017-01-01

Streptococcus agalactiae (group B Streptococcus, GBS) is a leading cause of invasive bacterial infections in newborns, typically acquired vertically during childbirth secondary to maternal vaginal colonization. Human milk oligosaccharides (HMOs) have important nutritional and biological activities

The β-Hemolysin and Intracellular Survival of Streptococcus agalactiae in Human Macrophages

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Sagar, Anubha; Klemm, Carolin; Hartjes, Lara; Mauerer, Stefanie; van Zandbergen, Ger; Spellerberg, Barbara

2013-01-01

S. agalactiae (group B streptococci, GBS) is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cell line and human granulocytes were infected with a serotype Ia S. agalactiae wild type strain and its isogenic nonhemolytic mutant. We could show that the nonhemolytic mutants were able to survive in significantly higher numbers than the hemolytic wild type strain, in THP-1 macrophage-like cells and in assays with human granulocytes. Intracellular bacterial multiplication, however, could not be observed. The hemolytic wild type strain stimulated a significantly higher release of Tumor Necrosis Factor-α than the nonhemolytic mutant in THP-1 cells, while similar levels of the chemokine Interleukin-8 were induced. In order to investigate bacterial mediators of IL-8 release in this setting, purified cell wall preparations from both strains were tested and found to exert a potent proinflammatory stimulus on THP-1 cells. In conclusion, our results indicate that the β-hemolysin has a strong influence on the intracellular survival of S. agalactiae and that a tightly controlled regulation of β-hemolysin expression is required for the successful establishment of S. agalactiae in different host niches. PMID:23593170

The β-hemolysin and intracellular survival of Streptococcus agalactiae in human macrophages.

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Anubha Sagar

Full Text Available S. agalactiae (group B streptococci, GBS is a major microbial pathogen in human neonates and causes invasive infections in pregnant women and immunocompromised individuals. The S. agalactiae β-hemolysin is regarded as an important virulence factor for the development of invasive disease. To examine the role of β-hemolysin in the interaction with professional phagocytes, the THP-1 monocytic cell line and human granulocytes were infected with a serotype Ia S. agalactiae wild type strain and its isogenic nonhemolytic mutant. We could show that the nonhemolytic mutants were able to survive in significantly higher numbers than the hemolytic wild type strain, in THP-1 macrophage-like cells and in assays with human granulocytes. Intracellular bacterial multiplication, however, could not be observed. The hemolytic wild type strain stimulated a significantly higher release of Tumor Necrosis Factor-α than the nonhemolytic mutant in THP-1 cells, while similar levels of the chemokine Interleukin-8 were induced. In order to investigate bacterial mediators of IL-8 release in this setting, purified cell wall preparations from both strains were tested and found to exert a potent proinflammatory stimulus on THP-1 cells. In conclusion, our results indicate that the β-hemolysin has a strong influence on the intracellular survival of S. agalactiae and that a tightly controlled regulation of β-hemolysin expression is required for the successful establishment of S. agalactiae in different host niches.

Isolation and characterization of Streptococcus spp. group B in Nile tilapias (Oreochromis niloticus reared in hapas nets and earth nurseries in the northern region of Parana State, Brazil

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Salvador Rogério

2005-01-01

Full Text Available The objective of this study was to isolate and characterize Streptococcus spp. in Nile tilapias (Oreochromis niloticus reared in net-pens and earth nurseries. Eight intensive tilapia-rearing farms were investigated in north Paraná, Brazil from April 1st 2001 to April 30th 2002. The fish were reared in a system of hapas nets on four farms and in earth nurseries on other four farms. A total of 370 samples were analyzed of material collected from 120 fish (brain, liver, kidney, skin scrapes, ascites liquid and eye that were sown on BHI agar (Brain Heart Infusion supplemented with 1% yeast extract and sheep blood. Streptococcus spp. was isolated in 36 of the samples (18 brain, eight liver, eight kidney and two ascites liquid from 25 fish. Streptococci were isolated in both systems, almost in the same proportion. First the streptococci were characterized by the catalase and esculin test, growth in methylene blue and sodium chloride at 6.5%. They were classified in groups by the Slidex Strepto-Kit (BioMerieux, France. The phenotypic characteristics were determined by the Api 20 Strep microtest system (BioMerieux, France. The 36 Streptococcus spp. samples did not present hemolysis and were classified as Lancefield group B. Further 16 samples were identified as Streptococcus agalactiae and 20 were not identified by the Api 20 Strep, but presented the same biochemical profile described for the reference strain of Streptococcus difficile (ND-2-22.

Latent class analysis of real time qPCR and bacteriological culturing for the diagnosis of Streptococcus agalactiae in cow composite milk samples.

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Holmøy, Ingrid H; Toft, Nils; Jørgensen, Hannah J; Mørk, Tormod; Sølverød, Liv; Nødtvedt, Ane

2018-06-01

Streptococcus agalactiae (S. agalactiae) has re-emerged as a mastitis pathogen among Norwegian dairy cows. The Norwegian cattle health services recommend that infected herds implement measures to eradicate S. agalactiae, this includes a screening of milk samples from all lactating cows. The performance of the qPCR-test currently in use for this purpose has not been evaluated under field conditions. The objective of this study was to estimate the sensitivity and specificity of the real-time qPCR assay in use in Norway (Mastitis 4 qPCR, DNA Diagnostics A/S, Risskov, Denmark) and compare it to conventional bacteriological culturing for detection of S. agalactiae in milk samples. Because none of these tests are considered a perfect reference test, the evaluation was performed using latent class models in a Bayesian analysis. Aseptically collected cow-composite milk samples from 578 cows belonging to 6 herds were cultured and tested by qPCR. While 37 (6.4%) samples were positive for S. agalactiae by bacteriological culture, 66 (11.4%) samples were positive by qPCR. The within-herd prevalence in the six herds, as estimated by the latent class models ranged from 7.7 to 50.8%. At the recommended cut-off (cycle threshold 37), the sensitivity of the qPCR was significantly higher at 95.3 (95% posterior probability interval [PPI] [84.2; 99.6]) than that of bacteriological culture at 58.2 (95% PPI [43.8; 74.4]). However, bacterial culture had a higher specificity of 99.7 (95% PPI [98.5; 100.0]) compared to the qPCR at 98.5 (95% PPI [94.6; 99.9]). The median estimated negative predictive values of qPCR was consistently higher than those of the BC at all estimated prevalences, and the superiority of the qPCR increased with increasing within-herd prevalence. The median positive predictive values of BC was in general higher than the estimates for the qPCR, however, at the highest prevalence the predictive ability of both tests were similar. Copyright © 2018 Elsevier B.V. All

PENGARUH LAMA DAN SUHU PENYIMPANAN EKSTRAK DAUN SIRIH HIJAU (Piper betle linn) DENGAN AQUADES TERHADAP DAYA HAMBAT BAKTERI Streptococcus agalactiae PENYEBAB MASTITIS PADA SAPI PERAH

OpenAIRE

Muhammad Sanjaya Kusuma; Tri Eko Susilorini; Puguh Surjowardojo

2017-01-01

Green betle leaf (Piper betle L.) is one of the plants used by the people of Indonesia for tradisional medicine. Green betle leaf contains antibacterial compounds consisting of phenol and its derivatives. This study aims to determine the antibacterial activity of green betle leaf (Piper betle L.) againt the bacteria Streptococcus agalactiae caused mastitis in dairy cows. Bacterial inhibition test by paper disc method. Data analysis using ANOVA by Nested design with 6 treatment and 6 repetitio...

VNTR analysis reveals unexpected genetic diversity within Mycoplasma agalactiae, the main causative agent of contagious agalactia

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Ayling Roger D

2008-11-01

Full Text Available Abstract Background Mycoplasma agalactiae is the main cause of contagious agalactia, a serious disease of sheep and goats, which has major clinical and economic impacts. Previous studies of M. agalactiae have shown it to be unusually homogeneous and there are currently no available epidemiological techniques which enable a high degree of strain differentiation. Results We have developed variable number tandem repeat (VNTR analysis using the sequenced genome of the M. agalactiae type strain PG2. The PG2 genome was found to be replete with tandem repeat sequences and 4 were chosen for further analysis. VNTR 5 was located within the hypothetical protein MAG6170 a predicted lipoprotein. VNTR 14 was intergenic between the hypothetical protein MAG3350 and the hypothetical protein MAG3340. VNTR 17 was intergenic between the hypothetical protein MAG4060 and the hypothetical protein MAG4070 and VNTR 19 spanned the 5' end of the pseudogene for a lipoprotein MAG4310 and the 3' end of the hypothetical lipoprotein MAG4320. We have investigated the genetic diversity of 88 M. agalactiae isolates of wide geographic origin using VNTR analysis and compared it with pulsed field gel electrophoresis (PFGE and random amplified polymorphic DNA (RAPD analysis. Simpson's index of diversity was calculated to be 0.324 for PFGE and 0.574 for VNTR analysis. VNTR analysis revealed unexpected diversity within M. agalactiae with 9 different VNTR types discovered. Some correlation was found between geographical origin and the VNTR type of the isolates. Conclusion VNTR analysis represents a useful, rapid first-line test for use in molecular epidemiological analysis of M. agalactiae for outbreak tracing and control.

Isolation and identification of bacterial pathogen from mastitis milk in Central Java Indonesia

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Harjanti, D. W.; Ciptaningtyas, R.; Wahyono, F.; Setiatin, ET

2018-01-01

Mastitis is a multi-etiologic disease of the mammary gland characterized mainly by reduction in milk production and milk quality due to intramammary infection by pathogenic bacteria. Nearly 83% of lactating dairy cows in Indonesia are infected with mastitis in various inflammation degrees. This study was conducted to isolate and identify the pathogen in milk collected from mastitis-infected dairy cows. The study was carried out in ten smallholder dairy farms in Central Java Indonesia based on animal examination, California mastitis test, isolation bacterial pathogens, Gram staining, Catalase and Coagulase test, and identification of bacteria species using Vitek. Bacteriological examination of milk samples revealed 15 isolates where Streptococcus was predominant species (73.3%) and the coagulase negative Staphylococcus species was identified at the least bacteria (26.7%). The Streptococcus bacteria found were Streptococcus uberis (2 isolates), Streptococcus sanguinis(6 isolates), Streptococcus dysgalactiaessp dysgalactiae(1 isolate) , Streptococcus mitis (1 isolate) and Streptococcus agalactiae (1 isolate). The Staphylococcus isolates comprising of Staphylococcus simulans (1 isolate) and Staphylococcus chromogens (3 isolates). Contamination of raw milkwith pathogenic bacteria can cause outbreaks of human disease (milk borne disease). Thus, proper milk processing method that couldinhibit the growth or kill these pathogenic bacteria is important to ensure the safety of milk and milk products.

Safety and immunogenicity of an oral DNA vaccine encoding Sip of Streptococcus agalactiae from Nile tilapia Oreochromis niloticus delivered by live attenuated Salmonella typhimurium.

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Huang, L Y; Wang, K Y; Xiao, D; Chen, D F; Geng, Y; Wang, J; He, Y; Wang, E L; Huang, J L; Xiao, G Y

2014-05-01

Attenuated Salmonella typhimurium SL7207 was used as a carrier for a reconstructed DNA vaccine against Streptococcus agalactiae. A 1.02 kb DNA fragment, encoding for a portion of the surface immunogenic protein (Sip) of S. agalactiae was inserted into pVAX1. The recombinant plasmid pVAX1-sip was transfected in EPC cells to detect the transient expression by an indirect immunofluorescence assay, together with Western blot analysis. The pVAX1-sip was transformed by electroporation into SL7207. The stability of pVAX1-sip into Salmonella was over 90% after 50 generations with antibiotic selection in vitro while remained stable over 80% during 35 generations under antibiotic-free conditions. The LD50 of SL/pVAX1-sip was 1.7 × 10(11) CFU/fish by intragastric administration which indicated a quite low virulence. Tilapias were inoculated orally at 10(8) CFU/fish, the recombinant bacteria were found present in intestinal tract, spleens and livers and eventually eliminated from the tissues 4 weeks after immunization. Fish immunized at 10(7), 10(8) and 10(9) CFU/fish with different immunization times caused various levels of serum antibody and an effective protection against lethal challenge with the wild-type strain S. agalactiae. Integration studies showed that the pVAX1-sip did not integrate with tilapia chromosomes. The DNA vaccine SL/pVAX1-sip was proved to be safe and effective in protecting tilapias against S. agalactiae infection. Copyright © 2014 Elsevier Ltd. All rights reserved.

Involvement of cholinergic and adenosinergic systems on the branchial immune response of experimentally infected silver catfish with Streptococcus agalactiae.

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Baldissera, M D; Souza, C F; Doleski, P H; Moreira, K L S; da Veiga, M L; da Rocha, M I U M; Santos, R C V; Baldisserotto, B

2018-01-01

It has been recognized that the cholinergic and adenosinergic systems have an essential role in immune and inflammatory responses during bacterial fish pathogens, such as the enzymes acetylcholinesterase (AChE) and adenosine deaminase (ADA), which are responsible for catalysis of the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado) respectively. Thus, the aim of this study was to investigate the involvement of the cholinergic and adenosinergic systems on the immune response and inflammatory process in gills of experimentally infected Rhamdia quelen with Streptococcus agalactiae. Acetylcholinesterase activity decreased, while ACh levels increased in gills of infected animals compared to uninfected animals. On the other hand, a significant increase in ADA activity with a concomitant decrease in Ado levels was observed in infected animals compared to uninfected animals. Based on this evidence, we concluded that infection by S. agalactiae in silver catfish alters the cholinergic and adenosinergic systems, suggesting the involvement of AChE and ADA activities on immune and inflammatory responses, regulating the ACh and Ado levels. In summary, the downregulation of AChE activity exerts an anti-inflammatory profile in an attempt to reduce or prevent the tissue damage, while the upregulation of ADA activity exerts a pro-inflammatory profile, contributing to disease pathophysiology. © 2017 John Wiley & Sons Ltd.

Streptococcus loxodontisalivarius sp. nov. and Streptococcus saliviloxodontae sp. nov., isolated from oral cavities of elephants.

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Saito, Masanori; Shinozaki-Kuwahara, Noriko; Hirasawa, Masatomo; Takada, Kazuko

2014-09-01

Four Gram-stain-positive, catalase-negative, coccoid-shaped organisms were isolated from elephant oral cavities. The isolates were tentatively identified as streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequencing studies confirmed the organisms to be members of the genus Streptococcus. Two isolates (NUM 6304(T) and NUM 6312) were related most closely to Streptococcus salivarius with 96.8 % and 93.1 % similarity based on the 16S rRNA gene and the RNA polymerase β subunit encoding gene (rpoB), respectively, and to Streptococcus vestibularis with 83.7 % similarity based on the 60 kDa heat-shock protein gene (groEL). The other two isolates (NUM 6306(T) and NUM 6318) were related most closely to S. vestibularis with 97.0 % and 82.9 % similarity based on the 16S rRNA and groEL genes, respectively, and to S. salivarius with 93.5 % similarity based on the rpoB gene. Based on phylogenetic and phenotypic evidence, these isolates are suggested to represent novel species of the genus Streptococcus, for which the names Streptococcus loxodontisalivarius sp. nov. (type strain NUM 6304(T) = JCM 19287(T) = DSM 27382(T)) and Streptococcus saliviloxodontae sp. nov. (type strain NUM 6306(T) = JCM 19288(T) = DSM 27513(T)) are proposed. © 2014 IUMS.

Serine-rich repeat proteins and pili promote Streptococcus agalactiae colonization of the vaginal tract.

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Sheen, Tamsin R; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M; Doran, Kelly S

2011-12-01

Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal vaginal colonization poses a significant risk to the newborn; however, little is known about the specific bacterial factors that promote GBS colonization and persistence in the female reproductive tract. We have developed in vitro models of GBS interaction with the human female cervicovaginal tract using human vaginal and cervical epithelial cell lines. Analysis of isogenic mutant GBS strains deficient in cell surface organelles such as pili and serine-rich repeat (Srr) proteins shows that these factors contribute to host cell attachment. As Srr proteins are heavily glycosylated, we confirmed that carbohydrate moieties contribute to the effective interaction of Srr-1 with vaginal epithelial cells. Antibody inhibition assays identified keratin 4 as a possible host receptor for Srr-1. Our findings were further substantiated in an in vivo mouse model of GBS vaginal colonization, where mice inoculated with an Srr-1-deficient mutant exhibited decreased GBS vaginal persistence compared to those inoculated with the wild-type (WT) parental strain. Furthermore, competition experiments in mice showed that WT GBS exhibited a significant survival advantage over the ΔpilA or Δsrr-1 mutant in the vaginal tract. Our results suggest that these GBS surface proteins contribute to vaginal colonization and may offer new insights into the mechanisms of vaginal niche establishment.

Isolation of Streptococcus tigurinus - a novel member of Streptococcus mitis group from a case of periodontitis.

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Dhotre, Shree V; Mehetre, Gajanan T; Dharne, Mahesh S; Suryawanshi, Namdev M; Nagoba, Basavraj S

2014-08-01

Streptococcus tigurinus is a new member of the Streptococcus viridians group and is closely related to Streptococcus mitis, Streptococcus pneumoniae, Streptococcus pseudopneumoniae, Streptococcus oralis, and Streptococcus infantis. The type strain AZ_3a(T) of S. tigurinus was originally isolated from a patient with infective endocarditis. Accurate identification of S. tigurinus is facilitated only by newer molecular methods like 16S rRNA gene analysis. During the course of study on bacteraemia and infective endocarditis with reference to periodontitis and viridians group of streptococci, a strain of S. tigurinus isolated from subgingival plaque of a patient with periodontitis identified by 16S rRNA gene analysis, which was originally identified as Streptococcus pluranimalium by Vitek 2. Confirmation by 16S rRNA gene analysis showed 99.39% similarity (1476/1485 bp) with S. tigurinus AZ_3a(T) (AORU01000002). To the best of our knowledge, this is the first report of isolation of S. tigurinus from the oral cavity of a periodontitis patient. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Indirect enzyme-linked immunosorbent assay method based on Streptococcus agalactiae rSip-Pgk-FbsA fusion protein for detection of bovine mastitis.

Science.gov (United States)

Bu, Ri-E; Wang, Jin-Liang; Wu, Jin-Hua; Xilin, Gao-Wa; Chen, Jin-Long; Wang, Hua

2017-03-01

The aim of this study was to establish a rapid and accurate method for the detection of the Streptococcus agalactiae antibody (SA-Ab) to determine the presence of the bovine mastitis (BM)-causative pathogen. The multi-subunit fusion protein rSip-Pgk-FbsA was prokaryotically expressed and purified. The triple activities of the membrane surface-associated proteins Sip, phosphoglycerate kinase (Pgk), and fibronectin (FbsA) were used as the diagnostic antigens to establish an indirect enzyme-linked immunosorbent assay (ELISA) method for the detection of SA-Ab in BM. The optimal antigen coating concentration was 2 μg/mL, the optimal serum dilution was 1:160, and the optimal dilution of the enzyme-labeled secondary antibody was 1:6000. The sensitivity, specificity, and repeatability tests showed that the method established in this study had no cross-reaction with antibodies to Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis in the sera. The results of the sensitivity test showed that a positive result could be obtained even if the serum dilution reached 1:12,800, indicating the high sensitivity and good repeatability of the method. The positive coincidence rate of this method was 98.6%, which is higher than that of previous tests established with the Sip or Pgk mono-antigen fusion protein, respectively, demonstrating the relatively higher sensitivity of this newly established method. The detection rate for 389 clinical samples was 46.53%. The indirect ELISA method established in this study could provide a more accurate and reliable serological method for the rapid detection of S. agalactiae in cases of BM.

Streptococcus oriloxodontae sp. nov., isolated from the oral cavities of elephants.

Science.gov (United States)

Shinozaki-Kuwahara, Noriko; Saito, Masanori; Hirasawa, Masatomo; Takada, Kazuko

2014-11-01

Two strains were isolated from oral cavity samples of healthy elephants. The isolates were Gram-positive, catalase-negative, coccus-shaped organisms that were tentatively identified as a streptococcal species based on the results of biochemical tests. Comparative 16S rRNA gene sequence analysis suggested classification of these organisms in the genus Streptococcus with Streptococcus criceti ATCC 19642(T) and Streptococcus orisuis NUM 1001(T) as their closest phylogenetic neighbours with 98.2 and 96.9% gene sequence similarity, respectively. When multi-locus sequence analysis using four housekeeping genes, groEL, rpoB, gyrB and sodA, was carried out, similarity of concatenated sequences of the four housekeeping genes from the new isolates and Streptococcus mutans was 89.7%. DNA-DNA hybridization experiments suggested that the new isolates were distinct from S. criceti and other species of the genus Streptococcus. On the basis of genotypic and phenotypic differences, it is proposed that the novel isolates are classified in the genus Streptococcus as representatives of Streptococcus oriloxodontae sp. nov. The type strain of S. oriloxodontae is NUM 2101(T) ( =JCM 19285(T) =DSM 27377(T)). © 2014 IUMS.

Phenotypic and genotypic antimicrobial susceptibility pattern of Streptococcus spp. isolated from cases of clinical mastitis in dairy cattle in Poland.

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Kaczorek, E; Małaczewska, J; Wójcik, R; Rękawek, W; Siwicki, A K

2017-08-01

Mastitis of dairy cattle is one of the most frequently diagnosed diseases worldwide. The main etiological agents of mastitis are bacteria of the genus Streptococcus spp., in which several antibiotic resistance mechanisms have been identified. However, detailed studies addressing this problem have not been conducted in northeastern Poland. Therefore, the aim of our study was to analyze, on phenotypic and genotypic levels, the antibiotic resistance pattern of Streptococcus spp. isolated from clinical cases of mastitis from dairy cattle in this region of Poland. The research was conducted using 135 strains of Streptococcus (Streptococcus uberis, n = 53; Streptococcus dysgalactiae, n = 41; Streptococcus agalactiae, n = 27; other streptococci, n = 14). The investigation of the antimicrobial susceptibility to 8 active substances applied in therapy in the analyzed region, as well as a selected bacteriocin (nisin), was performed using the minimum inhibitory concentration method. The presence of selected resistance genes (n = 14) was determined via PCR. We also investigated the correlation between the presence of resistance genes and the antimicrobial susceptibility of the examined strains in vitro. The highest observed resistance of Streptococcus spp. was toward gentamicin, kanamycin, and tetracycline, whereas the highest susceptibility occurred toward penicillin, enrofloxacin, and marbofloxacin. Additionally, the tested bacteriocin showed high efficacy. The presence of 13 analyzed resistance genes was observed in the examined strains [gene mef(A) was not detected]. In most strains, at least one resistance gene, mainly responsible for resistance to tetracyclines [tet(M), tet(K), tet(L)], was observed. However, a relationship between the presence of a given resistance gene and antimicrobial susceptibility on the phenotypic level was not always observed. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Desempenho e hematologia de tilápias-do-nilo alimentadas com Saccharomyces cerevisiae e vacinadas contra Streptococcus agalactiae

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Rogério Salvador

2013-08-01

Full Text Available O objetivo deste trabalho foi avaliar a inter-relação entre a suplementação alimentar com parede celular de Saccharomyces cerevisae e a vacinação contra Streptococcus agalactiae e seu efeito sobre o desempenho produtivo e as variáveis hematológicas de tilápia-do-nilo (Oreochromis niloticus. Oitenta e quatro tilápias-do-nilo foram distribuídas em 12 caixas de fibra (n=7, em arranjo fatorial 2x2x3, correspondente a dois níveis de suplementação com parede celular de levedura, dois tipos de inoculação e três tempos de avaliação. Os peixes foram alimentados durante 77 dias. A vacinação dos peixes foi realizada 60 dias após o início da alimentação. Quinze dias após a vacinação, todos os peixes foram submetidos ao desafio com cepa viva de S. agalactiae, e 6, 24 e 48 horas após o desafio, o sangue foi colhido da veia caudal para avaliações. Peixes alimentados com ração suplementada apresentam maior ganho de peso e taxa de crescimento específico, e a interação entre os efeitos da dieta e da vacinação resulta em maiores taxas de hematócrito, hemoglobina e leucócitos.

Loop-mediated isothermal amplification assay for rapid detection of Streptococcus agalactiae (group B streptococcus) in vaginal swabs - a proof of concept study.

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McKenna, James Patrick; Cox, Ciara; Fairley, Derek John; Burke, Rachael; Shields, Michael D; Watt, Alison; Coyle, Peter Valentine

2017-03-01

Neonatal sepsis caused by Streptococcus agalactiae [group B streptococcus (GBS)] is a life-threatening condition, which is preventable if colonized mothers are identified and given antibiotic prophylaxis during labour. Conventional culture is time consuming and unreliable, and many available non-culture diagnostics are too complex to implement routinely at point of care. Loop-mediated isothermal amplification (LAMP) is a method that, enables the rapid and specific detection of target nucleic acid sequences in clinical materials without the requirement for extensive sample preparation. A prototype LAMP assay targeting GBS sip gene is described. The assay was 100 % specific for GBS, with a limit of detection of 14 genome copies per reaction. The clinical utility of the LAMP assay for rapid direct molecular detection of GBS was determined by testing a total of 157 vaginal swabs with minimal sample processing using a rapid lysis solution. Compared to a reference quantitative real-time PCR assay, the direct LAMP protocol had a sensitivity and specificity of 95.4 and 100 %, respectively, with positive and negative predictive values of 100 and 98.3 %, respectively. Positive and negative likelihood ratios were infinity and 0.05, respectively. The direct LAMP method required a mean time of 45 min from the receipt of a swab to generation of a confirmed result, compared to 2 h 30 min for the reference quantitative real-time PCR test. The direct LAMP protocol described is easy to perform, facilitating rapid and accurate detection of GBS in vaginal swabs. This test has a potential for use at point of care.

Interaction of Streptococcus agalactiae and cellular innate immunity in colonization and disease

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Sybille eLandwehr-Kenzel

2014-10-01

Full Text Available Streptococcus agalactiae (Group B streptococcus, GBS is highly adapted to humans, where it is a normal constituent of the intestinal and vaginal flora. Yet, GBS has highly invasive potential and causes excessive inflammation, sepsis and death at the beginning of life, in the elderly and in diabetic patients. Thus GBS is a model pathobiont that thrives in the healthy host, but has not lost its potential virulence during coevolution with mankind. It remains incompletely understood how the innate immune system contains GBS in the natural niches, the intestinal and genital tracts, and which molecular events underlie breakdown of mucocutaneous resistance. Newborn infants between days seven and 90 of life are at risk of a particularly striking sepsis manifestation (late onset disease, LOD, where the transition from colonization to invasion and dissemination, and thus from health to severe sepsis is typically fulminant and not predictable. The great majority of late-onset sepsis cases is caused by one clone, GBS ST-17, which expresses HvgA as a signature virulence factor and adhesin. In mice, HvgA promotes the crossing of both the mucosal and the blood brain barrier. Expression levels of HvgA and other GBS virulence factors, such as pili and toxins, are regulated by the upstream two-component control system CovR/S. This in turn is modulated by acidic epithelial pH, high glucose levels and during the passage through the mouse intestine. After invasion, GBS has the ability to subvert innate immunity by mechanisms like GAPDH-dependent induction of IL-10 and β-protein binding to the inhibitory phagocyte receptors sialic acid binding immunoglobulin-like lectin 5 and 14. On the host side, sensing of GBS nucleic acids and lipopeptides by both Toll-like receptors (TLRs and the inflammasome appears to be critical for host resistance against GBS. Yet, comprehensive models on the interplay between GBS and human immune cells at the colonizing site are just

Serine-Rich Repeat Proteins and Pili Promote Streptococcus agalactiae Colonization of the Vaginal Tract ▿

Science.gov (United States)

Sheen, Tamsin R.; Jimenez, Alyssa; Wang, Nai-Yu; Banerjee, Anirban; van Sorge, Nina M.; Doran, Kelly S.

2011-01-01

Streptococcus agalactiae (group B streptococcus [GBS]) is a Gram-positive bacterium found in the female rectovaginal tract and is capable of producing severe disease in susceptible hosts, including newborns and pregnant women. The vaginal tract is considered a major reservoir for GBS, and maternal vaginal colonization poses a significant risk to the newborn; however, little is known about the specific bacterial factors that promote GBS colonization and persistence in the female reproductive tract. We have developed in vitro models of GBS interaction with the human female cervicovaginal tract using human vaginal and cervical epithelial cell lines. Analysis of isogenic mutant GBS strains deficient in cell surface organelles such as pili and serine-rich repeat (Srr) proteins shows that these factors contribute to host cell attachment. As Srr proteins are heavily glycosylated, we confirmed that carbohydrate moieties contribute to the effective interaction of Srr-1 with vaginal epithelial cells. Antibody inhibition assays identified keratin 4 as a possible host receptor for Srr-1. Our findings were further substantiated in an in vivo mouse model of GBS vaginal colonization, where mice inoculated with an Srr-1-deficient mutant exhibited decreased GBS vaginal persistence compared to those inoculated with the wild-type (WT) parental strain. Furthermore, competition experiments in mice showed that WT GBS exhibited a significant survival advantage over the ΔpilA or Δsrr-1 mutant in the vaginal tract. Our results suggest that these GBS surface proteins contribute to vaginal colonization and may offer new insights into the mechanisms of vaginal niche establishment. PMID:21984789

The Effect of Decoction Leaves from Green Leaf (piper betle l. to Inhibition Activity of Streptococcus Agalactiae Cause of Mastitis in Dairy Cow

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Oki Selfiana Marsono

2017-07-01

Full Text Available ABSTRACT This research was conducted from January to February 2017 at Microbiology Laboratory, Faculty Science and Technology, Islamic Maulana Maliki Ibrahim University, Malang and at Microbiology Laboratory, Faculty of Science, Muhammadiyah University, Malang. The purpose of this research was to determine the effectiveness of Piper betle L. leave extract on antibacterial activity the growth of Streptococcus agalactiae. The method used was Complete Randomized Design (CRD with 8 treatments and 6 replications. Piper betle L. leaves extract was used 20% for P0 (0-day, P1 (first day, P2 (second day, P3 (third day, P4 (fourth day, P5 (fiveth day, P6 (sixth days and P7 (seventh day. The results showed that Piper betle L. leaves extract had a highly significant effect (P<0.01 on inhibiting the growth of the bacteria so the results were continued with LSD test analysys because there were differences among variables. The results showed that P0 was the highest (3.93±0.50; then followed by P1 (3.83±0.69; P2 (3.47±0.21; P3 (3.13±0.22; P4 (3.12±0.58; P5 (3.04±0.24; P6 (3.00±0.44 include at medium categories, and P7 (2.97±0.19 include at low category, where inhibition zone which formed on each treatment have non significant decreased. In conclusion, the storage of Piper betle L. extract have effect on antibacterial activities (Streptococcus agalactiae, which the highest at day-0.

STREPTOCOCCUS: A WORLDWIDE FISH HEALTH PROBLEM

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Streptococcus iniae and S. agalactiae are important emergent pathogens that affect many fish species worldwide, especially in warm-water regions. In marine and freshwater systems, these Gram-positive bacteria cause significant economic losses, estimated at hundreds of millions of dollars annually. ...

Detection and enumeration of Staphylococcus aureus and Streptococcus agalactiae in milk by Real-Time PCR

OpenAIRE

Aline Gerato Dibbern

2015-01-01

O presente trabalho foi organizado em dois estudos. O objetivo do primeiro estudo foi determinar o efeito da infecção intramamária (IIM) causada por S. aureus e S. agalactiae na contagem de células somáticas (CCS) e na composição do leite (gordura, proteína, lactose, sólidos totais e extrato seco desengordurado), o efeito da contagem de S. aureus e S. agalactiae sobre a composição do leite e a estimativa da frequência de vacas e de quartos infectados com S. aureus e S. agalactiae por meio da ...

Estimation of test characteristics of real-time PCR and bacterial culture for diagnosis of subclinical intramammary infections with Streptococcus agalactiae in Danish dairy cattle in 2012 using latent class analysis.

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Mahmmod, Yasser S; Toft, Nils; Katholm, Jørgen; Grønbæk, Carsten; Klaas, Ilka C

2013-05-01

The misdiagnosis of intramammary infections (IMI) with Streptococcus agalactiae (S. agalactiae) could lead farmers to treat or cull animals unnecessarily. The objective of this field study was to estimate the sensitivity (Se) and specificity (Sp) of real-time PCR at different cut-offs for cycle threshold (Ct) values against bacterial culture (BC) for diagnosis of S. agalactiae IMI using latent class analysis to avoid the assumption of a perfect reference test. A total of 614 dairy cows were randomly selected from 6 herds with bulk tank PCR Ct value ≤ 39 for S. agalactiae and S. aureus. At milk recording, 2456 quarter milk samples were taken aseptically for BC and the routinely taken cow level milk samples were analyzed by PCR. Results showed that 53 cows (8.6%) were positive for S. agalactiae IMI by BC. Sensitivity of PCR at cut-offs; ≤ 39, ≤ 37, ≤ 34, and ≤ 32, was 96.2%, 91.9%, 87.2% and 73.9%, while Se of BC was 25.7%, 29.9%, 59.9% and 72.1%. Specificity of PCR at cut-offs; ≤ 39, ≤ 37, ≤ 34, and ≤ 32, was 96.8%, 96.9%, 96.7%, and 97.22%, while Sp of BC was 99.7%, 99.5%, 99.2%, and 98.9%. The estimated prevalence of S. agalactiae IMI by PCR was higher than the apparent prevalence at the tested cut-offs, indicating under estimation of S. agalactiae IMI in the examined dairy cows. In conclusion, Se of PCR is always higher than Se of BC at all tested cut-offs. The lower cut-off, the more comparable becomes Se of PCR and Se of BC. The changes in Se in both PCR and BC at different Ct-value cut-offs may indicate a change in the definition of the latent infection. The similar Se of both tests at cut-off ≤ 32 may indicate high concentrations of S. agalactiae viable cells, representing a cow truly/heavily infected with S. agalactiae and thus easier to detect with BC. At cut-off ≤ 39 the latent definition of infection may reflect a more general condition of cows being positive for S. agalactiae. Our findings indicate that PCR Ct-value cut-offs should

Consideraciones sobre elaislamiento en exudados vaginales de Streptococcus morbillorum

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J.M. F. Egido

1995-06-01

Full Text Available De el estúdio de 195 exudados vaginales enviados por el Servicio de Ginecologia de este hospital, durante el período 1988-1990, hemos seleccionado aquellos en los que el cultivo fue positivo para estreptococos, 58 (30% de los cuales 26 (44.8% correspondia a Streptococcus morbillorum, 9 (15.5% a Gardnerella vaginalis, 5 (8.6% a Enterococcus faecalis-durans, y a Streptococcus agalactiae, 3 (5.1% a Streptococcus mitis y Streptococcus mitis, 2 (3-4% a Streptococcus bovis y Streptococcus cremoris y 1 (1.7% a Streptococcus salivarius, Streptococcus equinus y Strptococcus sanguis II respectivamente. En todos los casos se observo antecedentes de actuacción medico- quirurjica en el tracto genital, y en el 52.8% de los casos fuô concomitante con el diagnostico clinico-micologico de candidiasis vaginal. La ideittificaccion bacteriologica se realizo mediante el sistema API 20 STREP (sistema api bioMêríeux GmbH, Nütingen, Alemania dando un patron tipico ("excelente identificacción" para el Streptococcus morbillorum.We have tested 195 vaginal secretions sent by Gynecology Service of this hospital between the years 1988 - 1990. We achieved positive culture for streptococci in 58 (30% of these cultures, 26 (44.8% corresponding to Streptococcus morbillorum 9 (15.5%, to Gardnerella vaginalis 5 (8.6%, to Enterococcus faecalis-durans and to Streptococcus agalactiae, 3 (5.1 % to Streptococcus mitis and milleri 2 (3-4%, to Streptococcus bovis and cremoris, and 1 (1.7% to Streptococcus salivarius, equinus and sanguis II respectively. We previously found that 52.8% of these patients were positive for vaginal candidiasis. The bacteriological identification done by the API 20 STREP System (bioMerieux GmbH, Nútingen, Germanyprovides a typical pattern ("good identification" for the Streptococcus morbillorum.

First Isolation of Streptococcus halichoeri and Streptococcus phocae from a Steller Sea Lion (Eumetopias jubatus) in South Korea.

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Lee, Kichan; Kim, Ji-Yeon; Jung, Suk Chan; Lee, Hee-Soo; Her, Moon; Chae, Chanhee

2016-01-01

Streptococcus species are emerging potential pathogens in marine mammals. We report the isolation and identification of Streptococcus halichoeri and Streptococcus phocae in a Steller sea lion (Eumetopias jubatus) in South Korea.

Effect Of Gamma Ray Irradiation On Streptococcus Agalactiae Growth For Vaccine Agent Of Mastitis Disease In Dairy Cattle

International Nuclear Information System (INIS)

Jeane Tuasikal, B; Sugoro, I; Tjiptosumirat, T; Lina, M

2003-01-01

A study has been conducted to determine the effect of gamma ray irradiation to attenuate infectivity of S. agalactiae as dominant bacteria causing mastitis in dairy cattle. The aim of the study is obtaining optimum irradiation dosage to provide radio vaccine for mastitis. S. agalactiae isolate bacteria of which has reach the mid log-phase was cultured and divided into 6 treatment groups of irradiation doses, i.e. 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. Following irradiation, bacteria were then cultured in BHI agar media for colony counting to determine the LD 50 , resulting 7.5x10 8 ; 5.0x10 7 ; 7.0x10 6 ; 9.5x10 5 ; 1.5x10 4 ; and 3.5x10 3 cell/ml, respectively. Result of this study shows the higher irradiation doses the lower number of bacteria per ml, and LD 50 , which found to be under 0.2 kGy of irradiation dose

Molecular characteristics of Streptococcus agalactiae in a mother-baby prospective cohort study: Implication for vaccine development and insights into vertical transmission.

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Li, Shunming; Wen, Guoming; Cao, Xuelian; Guo, Dan; Yao, Zhenjiang; Wu, Chuan'an; Ye, Xiaohua

2018-04-05

Streptococcus agalactiae (GBS) is a leading cause of neonatal sepsis and meningitis in many countries. This study aimed to determine the molecular characteristics of GBS colonized in mothers and their infants so as to provide implication for vaccine strategies and confirm vertical transmission. A prospective cohort study was conducted to recruit 1815 mother-neonate pairs. All GBS isolates from pregnant women and her infants were tested for serotypes, multilocus sequence types and virulence genes. The relationship between multiple molecular characteristics of GBS isolates was tested by the correspondence analysis, and the agreement between mother-neonate paired data in molecular characteristics was analyzed using Kappa tests. The predominant serotypes were III, Ia and V, and the most prevalent sequence types (STs) were ST19, ST17, ST10, and ST12. All isolates carried at least one pilus island (PI). The most common combination of PIs was PI-2b alone, followed by PI-1+PI-2a and PI-2a alone, and the most prevalent alpha-like protein (alp) genes were rib, epsilon and alphaC. Moreover, a strong relationship was noted between STs, serotypes, alp genes and PIs, including ST17 associated with serotype-III/rib/PI-2b, ST19 with serotype-III/rib/PI-1+PI-2a, and ST485 with serotype-Ia/epsilon/PI-2b. The rate of GBS vertical transmission was 14.1%, and the kappa test revealed good agreement in multiple molecular characteristics among GBS-positive mother-neonate pairs. Notably, the switching of molecular characteristics was found during vertical transmission. Our findings underscore the value of monitoring multiple molecular characteristics so as to provide implication for multivalent strategies and gain insights into GBS vertical transmission and vertical characteristic switching. Copyright © 2018 Elsevier Ltd. All rights reserved.

Contagious agalactia by Mycoplasma agalactiae in small ruminants in Brazil: first report Agalaxia contagiosa por Mycoplasma agalactiae em pequenos ruminantes no Brasil: primeiro relato

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Edisio Oliveira de Azevedo

2006-12-01

Full Text Available Two outbreaks of contagious agalactia by Mycoplasma agalactiae occurred in Paraíba State, Northeastern Region of Brazil are reported. The disease was characterized by mastitis, agalactia and polyarthritis in does and polyarthritis and conjunctivitis in kids and lambs. Fever and anorexia were also observed. Morbidy was from 26.1% to 100% in does, 36.5 to 100% in kids and 49% in lambs. In one farm 14.3% of the lactating goats and 6.4% of the kids died or were euthanized. In the other, 3.3% of the does, 36.5% of the kids and 22.9% of the lambs died and 84 affected goats were euthanized to control the disease. M. agalactiae was isolated from milk, joint exudates, nasal swabs and ear washings. The colonies were characteristic of Mycoplasma and the agent did not ferment both glucose and arginin. It was typed as Mycoplasma agalactiae by immunoperoxidase and PCR. This is the first report of M. agalactiae infection in Brazil, but the source of the infection remains unknown.Dois surtos de agalaxia contagiosa causada por Mycoplasma agalactiae são descritos no Estado da Paraíba, região Nordeste do Brasil. A doença caracterizou-se por mastite, agalaxia e poliartrite em cabras e poliartrite e cerato-conjuntivite em cabritos e cordeiros. Febre e anorexia também foram observadas. A morbidade variou de 26,1% a 100% nas cabras, 36,5% a 100% em cabritos e 49,0% em cordeiros. Na primeira fazenda, 14,3% das cabras em lactação e 6,4% dos cabritos morreram ou foram sacrificados. Na outra propriedade, 3,3% dos caprinos adultos, 36,5% dos cabritos e 22,9% dos cordeiros morreram e outros 84 caprinos foram sacrificados para controle da doença. M. agalactiae foi isolado a partir de leite, líquido articular, suabe nasal e lavado do conduto auditivo externo. Colônias características de Mycoplasma e que não fermentaram a glicose e arginina foram observadas. A identificação de M. agalactiae foi realizada por imunoperoxidase indireta e PCR. Sendo assim, M

[Evaluation of Prolex for the rapid identification of streptococci isolated in medical microbiology].

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Loubinoux, J; Mihaila-Amrouche, L; Bouvet, A

2004-10-01

The need to rapidly identify streptococci responsible for acute infectious diseases has led to the development of agglutination techniques that are able to identify streptococcal group antigens (A, B, C, D, F, and G) directly from primoculture colonies on blood agar. The Prolex agglutination tests (Pro-Lab Diagnostics, Richmond Hill, Ontario, Canada), distributed in France by i2a, have been used for the determination of group antigens of 166 isolates of streptococci and enterococci previously identified in the National Reference Center for Streptococci. The results obtained with the Prolex reagents have permitted to correctly identify all pyogenic beta-hemolytic streptococci (23 Streptococcus pyogenes, 21 Streptococcus agalactiae, 33 Streptococcus dysgalactiae subsp. equisimilis including 6 group C and 27 group G, and 5 Streptococcus porcinus including 4 group B). Four differences between unexpected agglutinations (A or F) and species identifications have been obtained. These differences were observed for four non-hemolytic isolates of Streptococcus mutans, Streptococcus gordonii, Streptococcus infantarius, and Streptococcus suis. The anti-D reagent has been of value as a marker for isolates of enterococci. Thus, these results confirm the abilities of these agglutination tests for the grouping of beta-hemolytic streptococci. Moreover, the use of Prolex has the advantage to be rapid because of the non-enzymatic but chemical extraction of streptococcal antigens.

Expression, purification, crystallization and preliminary X-ray diffraction studies of the human keratin 4-binding domain of serine-rich repeat protein 1 from Streptococcus agalactiae

International Nuclear Information System (INIS)

Sundaresan, Ramya; Samen, Ulrike; Ponnuraj, Karthe

2011-01-01

Expression, purification and crystallization of Srr-1-K4BD, a human keratin 4-binding domain of serine-rich repeat protein 1 from S. agalactiae, was carried out. Native crystals of Srr-1-K4BD diffracted to 3.8 Å resolution using synchrotron radiation. Serine-rich repeat protein 1 (Srr-1) is a surface protein from Streptococcus agalactiae. A 17 kDa region of this protein has been identified to bind to human keratin 4 (K4) and is termed the Srr-1 K4-binding domain (Srr-1-K4BD). Recombinant Srr-1-K4BD was overexpressed in Escherichia coli BL21 (DE3) cells. Native and selenomethionine-substituted proteins were prepared using Luria–Bertani (LB) and M9 minimal media, respectively. A two-step purification protocol was carried out to obtain a final homogenous sample of Srr-1-K4BD. Crystals of native Srr-1-K4BD were obtained using PEG 3350 as a precipitant. The crystals diffracted to 3.8 Å resolution using synchrotron radiation and belonged to space group P2 1 , with unit-cell parameters a = 47.56, b = 59.48, c = 94.71 Å, β = 93.95°

Streptococcus tangierensis sp. nov. and Streptococcus cameli sp. nov., two novel Streptococcus species isolated from raw camel milk in Morocco.

Science.gov (United States)

Kadri, Zaina; Vandamme, Peter; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; Elfahime, El Mostafa; Farricha, Omar El; Swings, Jean; Amar, Mohamed

2015-02-01

Biochemical and molecular genetic studies were performed on two unidentified Gram-stain positive, catalase and oxidase negative, non-hemolytic Streptococcus-like organisms recovered from raw camel milk in Morocco. Phenotypic characterization and comparative 16S rRNA gene sequencing demonstrated that the two strains were highly different from each other and that they did not correspond to any recognized species of the genus Streptococcus. Phylogenetic analysis based on 16S rRNA gene sequences showed the unidentified organisms each formed a hitherto unknown sub-line within the genus Streptococcus, displaying a close affinity with Streptococcus moroccensis, Streptococcus minor and Streptococcus ovis. DNA G+C content determination, MALDI-TOF mass spectrometry and biochemical tests demonstrated the bacterial isolates represent two novel species. Based on the phenotypic distinctiveness of the new bacteria and molecular genetic evidence, it is proposed to classify the two strains as Streptococcus tangierensis sp. nov., with CCMM B832(T) (=LMG 27683(T)) as the type strain, and Streptococcus cameli sp. nov., with CCMM B834(T) (=LMG 27685(T)) as the type strain.

[Neonatal bacterial infection by maternal-fetal contamination: for a change in approach? 1. Detection of Streptococcus agalactiae infection: methods and evaluation of results].

Science.gov (United States)

Blond, M H; Gold, F; Pierre, F; Quentin, R; Aujard, Y

2001-10-01

Perinatal group B streptococcal infection has been the subject of numerous studies and despite guidelines established during the last decade remains a frequent disease with high mortality. The basic aim of the guidelines is to screen for Streptococcus agalactiae during the antepartum period in order to institute antibiotic therapy during delivery. A critical review of the literature highlights the real impact and adverse effect of these guidelines: difficult application (only two-thirds of all maternity units have a protocol and compliance is only 75%), maternal risks of antibiotic therapy (especially the emergence of resistant Gram negative bacteria), fetal risks (accentuation of neonatal sepsis with resistant strains, retarded neonatal infections, frequent use of antibiotics with a broader spectrum, higher frequency of nosocomial sepsis).

Comparative genomics of the dairy isolate Streptococcus macedonicus ACA-DC 198 against related members of the Streptococcus bovis/Streptococcus equinus complex.

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Papadimitriou, Konstantinos; Anastasiou, Rania; Mavrogonatou, Eleni; Blom, Jochen; Papandreou, Nikos C; Hamodrakas, Stavros J; Ferreira, Stéphanie; Renault, Pierre; Supply, Philip; Pot, Bruno; Tsakalidou, Effie

2014-04-08

Within the genus Streptococcus, only Streptococcus thermophilus is used as a starter culture in food fermentations. Streptococcus macedonicus though, which belongs to the Streptococcus bovis/Streptococcus equinus complex (SBSEC), is also frequently isolated from fermented foods mainly of dairy origin. Members of the SBSEC have been implicated in human endocarditis and colon cancer. Here we compare the genome sequence of the dairy isolate S. macedonicus ACA-DC 198 to the other SBSEC genomes in order to assess in silico its potential adaptation to milk and its pathogenicity status. Despite the fact that the SBSEC species were found tightly related based on whole genome phylogeny of streptococci, two distinct patterns of evolution were identified among them. Streptococcus macedonicus, Streptococcus infantarius CJ18 and Streptococcus pasteurianus ATCC 43144 seem to have undergone reductive evolution resulting in significantly diminished genome sizes and increased percentages of potential pseudogenes when compared to Streptococcus gallolyticus subsp. gallolyticus. In addition, the three species seem to have lost genes for catabolizing complex plant carbohydrates and for detoxifying toxic substances previously linked to the ability of S. gallolyticus to survive in the rumen. Analysis of the S. macedonicus genome revealed features that could support adaptation to milk, including an extra gene cluster for lactose and galactose metabolism, a proteolytic system for casein hydrolysis, auxotrophy for several vitamins, an increased ability to resist bacteriophages and horizontal gene transfer events with the dairy Lactococcus lactis and S. thermophilus as potential donors. In addition, S. macedonicus lacks several pathogenicity-related genes found in S. gallolyticus. For example, S. macedonicus has retained only one (i.e. the pil3) of the three pilus gene clusters which may mediate the binding of S. gallolyticus to the extracellular matrix. Unexpectedly, similar findings were

Occurrence, isolation and DNA identification of Streptococcus ...

African Journals Online (AJOL)

ajl yemi

2011-11-28

Nov 28, 2011 ... Streptococcus thermophilus involved in Algerian ... among reference, and wild strains of S. thermophilus and for their differentiation from Enterococcus spp. ..... Isolation and characterization of Lactobacillus delbrueckii ssp.

Comprehensive evaluation of immunomodulation by moderate hypoxia in S. agalactiae vaccinated Nile tilapia.

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Gallage, Sanchala; Katagiri, Takayuki; Endo, Masato; Maita, Masashi

2017-07-01

Streptococcus agalactiae is a major bacterial pathogen in tilapia aquaculture. Vaccines are known to provide protection but S. agalactiae clearance in tilapia can be reduced by marginal environmental conditions. Therefore, the purpose of this study is to examine S. agalactiae clearance in vaccinated Nile tilapia under moderate hypoxic (55± 5% DO) and normoxic (85 ± 5%DO) conditions. Fish were acclimatized to either moderate hypoxia or normoxia and immunized with formalin-inactivated S. agalactiae. Fish were experimentally challenged with S. agalactiae at 30 days post-vaccination. Serum antibody titer was significantly higher in vaccinated fish kept under normoxic condition compared to the moderate hypoxic condition at fifteen and thirty days post-vaccination. The cumulative mortality following challenge was significantly reduced in vaccinated fish kept under normoxic condition compared to those in moderate hypoxic condition reflecting that pre-challenge antibody titer may correlate with survival of fish. Blood and tissue pathogen burden detection of S. agalactiae studies revealed that culturable S. agalactiae cells could not be detected in the blood of normoxic vaccinated fish at all the sampling points. In contrast, fish vaccinated in moderate hypoxic condition had considerable number of culturable S. agalactiae cells in their blood up to 5 days following challenge. Phagocytosis and intracellular reactive oxygen species (ROS) production were lowered by moderate hypoxia in vitro. Furthermore, presence of specific antibodies and higher specific antibody level in the serum increased phagocytosis, ROS production and lowered intracellular survival of S. agalactiae in head kidney leukocytes. Overall this study has highlighted that S. agalactiae clearance in vaccinated Nile tilapia is modulated by moderate hypoxia. One of the possible explanations for this might be less efficient phagocytic activities due to low oxygen availability and lower specific

Streptococcus caprae sp. nov., isolated from Iberian ibex (Capra pyrenaica hispanica).

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Vela, A I; Mentaberre, G; Lavín, S; Domínguez, L; Fernández-Garayzábal, J F

2016-01-01

Biochemical and molecular genetic studies were performed on a novel Gram-stain-positive, catalase-negative, coccus-shaped organism isolated from tonsil samples of two Iberian ibexes. The micro-organism was identified as a streptococcal species based on its cellular, morphological and biochemical characteristics. 16S rRNA gene sequence comparison studies confirmed its identification as a member of the genus Streptococcus, but the organism did not correspond to any species of this genus. The nearest phylogenetic relative of the unknown coccus from ibex was Streptococcus porci 2923-03T (96.6 % 16S rRNA gene sequence similarity). Analysis based on rpoB and sodA gene sequences revealed sequence similarity values lower than 86.0 and 83.8 %, respectively, from the type strains of recognized Streptococcus species. The novel bacterial isolate was distinguished from Streptococcus porci and other Streptococcus species using biochemical tests. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as representing a novel species of the genus Streptococcus, for which the name Streptococcus caprae sp. nov. is proposed. The type strain is DICM07-02790-1CT ( = CECT 8872T = CCUG 67170T).

Isolation and antibiogram of Staphylococcus, Streptococcus and Escherichia coli isolates from clinical and subclinical cases of bovine mastitis

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Nihar Nalini Mohanty,

2013-08-01

Full Text Available Aim: The present study was aimed to isolate and evaluate the continuous change in the pattern of drug resistance showed by different mastitogenic organisms, isolated from clinical and subclinical cases of mastitis.Materials and Methods: The study was carried out using 150 milk samples received from various clinical and subclinical cases, from which the causative organisms were isolated and subjected to in vitro antibiotic sensitivity test.Results: The bacteriological analysis of the samples indicated the presence of both Gram positive and Gram negative organisms followed by isolation of isolates like Staphylococcus, E. coli, Streptococcus, Bacillus, Corynebacterium, Listeria, Klebsiella. The in vitro sensitivity of Staphylococcus, E. coli and Streptococcus isolates revealed that they were more sensitive towards newer antimicrobials like Levofloxacin and Enrofloxacin.Conclusion: The prevalence of Staphylococcus was found to be maximum followed by Streptococcus and E. coli among the isolated organisms. Levofloxacin and Enrofloxacin were found to be most effective against the targeted isolates.

Streptococcus moroccensis sp. nov. and Streptococcus rifensis sp. nov., isolated from raw camel milk.

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Kadri, Zaina; Amar, Mohamed; Ouadghiri, Mouna; Cnockaert, Margo; Aerts, Maarten; El Farricha, Omar; Vandamme, Peter

2014-07-01

Two catalase- and oxidase-negative Streptococcus-like strains, LMG 27682(T) and LMG 27684(T), were isolated from raw camel milk in Morocco. Comparative 16S rRNA gene sequencing assigned these bacteria to the genus Streptococcus with Streptococcus rupicaprae 2777-2-07(T) as their closest phylogenetic neighbour (95.9% and 95.7% similarity, respectively). 16S rRNA gene sequence similarity between the two strains was 96.7%. Although strains LMG 27682(T) and LMG 27684(T) shared a DNA-DNA hybridization value that corresponded to the threshold level for species delineation (68%), the two strains could be distinguished by multiple biochemical tests, sequence analysis of the phenylalanyl-tRNA synthase (pheS), RNA polymerase (rpoA) and ATP synthase (atpA) genes and by their MALDI-TOF MS profiles. On the basis of these considerable phenotypic and genotypic differences, we propose to classify both strains as novel species of the genus Streptococcus, for which the names Streptococcus moroccensis sp. nov. (type strain, LMG 27682(T)  = CCMM B831(T)) and Streptococcus rifensis sp. nov. (type strain, LMG 27684(T)  = CCMM B833(T)) are proposed. © 2014 IUMS.

Purinergic signaling modulates the cerebral inflammatory response in experimentally infected fish with Streptococcus agalactiae: an attempt to improve the immune response.

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Souza, Carine F; Baldissera, Matheus D; Bottari, Nathiele B; Moreira, Karen L S; da Rocha, Maria Izabel U M; da Veiga, Marcelo L; Santos, Roberto C V; Baldisserotto, Bernardo

2018-06-01

Appropriate control of the immune response is a critical determinant of fish health, and the purinergic cascade has an important role in the immune and inflammatory responses. This cascade regulates the levels of adenosine triphosphate (ATP), adenosine diphosphate, adenosine monophosphate and adenosine (Ado), molecules involved in physiological or pathological events as inflammatory and anti-inflammatory mediators. Thus, the aim of this study was to evaluate whether purinergic signaling, through the activities of nucleoside triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase, and adenosine deaminase (ADA), is capable of modulating the cerebral immune and inflammatory responses in silver catfish that is experimentally infected with Streptococcus agalactiae. Cerebral NTPDase (with ATP as substrate) and 5'-nucleotidase activities increased, while ADA activity decreased in silver catfish that is experimentally infected with S. agalactiae, compared to the control group. Moreover, the cerebral levels of ATP and Ado increased in infected animals compared to the uninfected control group. Brain histopathology in infected animals revealed inflammatory demyelination (the presence of occasional bubbly collections), increased cellular density in the area near to pia-mater and intercellular edema. Based on this evidence, the modulation of the purinergic cascade by the enzymes NTPDase, 5'-nucleotidase, and ADA exerts an anti-inflammatory profile due to the regulation of ATP and Ado levels. This suggests involvement of purinergic enzymes on streptococcosis pathogenesis, through regulating cerebral ATP and Ado levels, molecules known to participate in physiological or pathological events as inflammatory and anti-inflammatory mediators, respectively. In summary, the modulation of the cerebral purinergic cascade exerts an anti-inflammatory profile in an attempt to reduce inflammatory damage.

Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

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Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

2015-10-22

Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Exploring internal features of 16S rRNA gene for identification of clinically relevant species of the genus Streptococcus

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2011-01-01

Background Streptococcus is an economically important genus as a number of species belonging to this genus are human and animal pathogens. The genus has been divided into different groups based on 16S rRNA gene sequence similarity. The variability observed among the members of these groups is low and it is difficult to distinguish them. The present study was taken up to explore 16S rRNA gene sequence to develop methods that can be used for preliminary identification and can supplement the existing methods for identification of clinically-relevant isolates of the genus Streptococcus. Methods 16S rRNA gene sequences belonging to the isolates of S. dysgalactiae, S. equi, S. pyogenes, S. agalactiae, S. bovis, S. gallolyticus, S. mutans, S. sobrinus, S. mitis, S. pneumoniae, S. thermophilus and S. anginosus were analyzed with the purpose to define genetic variability within each species to generate a phylogenetic framework, to identify species-specific signatures and in-silico restriction enzyme analysis. Results The framework based analysis was used to segregate Streptococcus spp. previously identified upto genus level. This segregation was validated using species-specific signatures and in-silico restriction enzyme analysis. 43 uncharacterized Streptococcus spp. could be identified using this approach. Conclusions The markers generated exploring 16S rRNA gene sequences provided useful tool that can be further used for identification of different species of the genus Streptococcus. PMID:21702978

Streptococcus agalactie como agente etiológico de Doença Sexualmente Transmissível Streptococcus agalactie involved in the etiology of Sexually Transmitted Diseases

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Marcos Noronha Frey

2011-12-01

Full Text Available O Streptococcus agalactie é um importante micro-organismo causador de doenças em gestantes, neonatos, idosos (maiores de 65 anos de idade, e portadores de doenças crônicas debilitantes, sendo um patógeno incomum em pacientes que não se enquadrem nestas faixas etárias ou perfil clínico (1-5, e, raramente, é descrito como agente causador de doenças sexualmente transmissíveis. Descrevemos o caso de um adulto jovem hígido de 19 anos, apresentando lesões ulceradas genitais e oral, assim como corrimento uretral e ocular, sugestivas de terem sido causadas pelo Streptococcus agalactie, e adquiridas através do contato sexual (doenças sexualmente transmissíveis.Streptococcus agalactiae is an important microorganism involved in a number of conditions in pregnant women, newborns, elderly people (over 65 years of age and individuals with chronic disabling illnesses. This pathogen is infrequently found among patients outside this age range or clinical profile(1-5 and is rarely reported in the etiology of sexually transmitted diseases. Here we describe a case of an otherwise healthy 19 year-old male, who presented with ulcerative genital and oral lesions in association with urethral and ocular discharge, suggestive of Streptococcus agalactiae infection acquired through sexual contact.

Evidence for Rare Capsular Switching in Streptococcus agalactiae▿

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Martins, Elisabete Raquel; Melo-Cristino, José; Ramirez, Mário

2010-01-01

The polysaccharide capsule is a major antigenic factor in Streptococcus agalactiae (Lancefield group B streptococcus [GBS]). Previous observations suggest that exchange of capsular loci is likely to occur rather frequently in GBS, even though GBS is not known to be naturally transformable. We sought to identify and characterize putative capsular switching events, by means of a combination of phenotypic and genotypic methods, including pulsed-field gel electrophoretic profiling, multilocus sequence typing, and surface protein and pilus gene profiling. We show that capsular switching by horizontal gene transfer is not as frequent as previously suggested. Serotyping errors may be the main reason behind the overestimation of capsule switching, since phenotypic techniques are prone to errors of interpretation. The identified putative capsular transformants involved the acquisition of the entire capsular locus and were not restricted to the serotype-specific central genes, the previously suggested main mechanism underlying capsular switching. Our data, while questioning the frequency of capsular switching, provide clear evidence for in vivo capsular transformation in S. agalactiae, which may be of critical importance in planning future vaccination strategies against this pathogen. PMID:20023016

Consideraciones sobre elaislamiento en exudados vaginales de Streptococcus morbillorum

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J.M. F. Egido

1995-06-01

Full Text Available De el estúdio de 195 exudados vaginales enviados por el Servicio de Ginecologia de este hospital, durante el período 1988-1990, hemos seleccionado aquellos en los que el cultivo fue positivo para estreptococos, 58 (30% de los cuales 26 (44.8% correspondia a Streptococcus morbillorum, 9 (15.5% a Gardnerella vaginalis, 5 (8.6% a Enterococcus faecalis-durans, y a Streptococcus agalactiae, 3 (5.1% a Streptococcus mitis y Streptococcus mitis, 2 (3-4% a Streptococcus bovis y Streptococcus cremoris y 1 (1.7% a Streptococcus salivarius, Streptococcus equinus y Strptococcus sanguis II respectivamente. En todos los casos se observo antecedentes de actuacción medico- quirurjica en el tracto genital, y en el 52.8% de los casos fuô concomitante con el diagnostico clinico-micologico de candidiasis vaginal. La ideittificaccion bacteriologica se realizo mediante el sistema API 20 STREP (sistema api bioMêríeux GmbH, Nütingen, Alemania dando un patron tipico ("excelente identificacción" para el Streptococcus morbillorum.

Genome characterization and population genetic structure of the zoonotic pathogen, Streptococcus canis

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Richards Vincent P

2012-12-01

Full Text Available Abstract Background Streptococcus canis is an important opportunistic pathogen of dogs and cats that can also infect a wide range of additional mammals including cows where it can cause mastitis. It is also an emerging human pathogen. Results Here we provide characterization of the first genome sequence for this species, strain FSL S3-227 (milk isolate from a cow with an intra-mammary infection. A diverse array of putative virulence factors was encoded by the S. canis FSL S3-227 genome. Approximately 75% of these gene sequences were homologous to known Streptococcal virulence factors involved in invasion, evasion, and colonization. Present in the genome are multiple potentially mobile genetic elements (MGEs [plasmid, phage, integrative conjugative element (ICE] and comparison to other species provided convincing evidence for lateral gene transfer (LGT between S. canis and two additional bovine mastitis causing pathogens (Streptococcus agalactiae, and Streptococcus dysgalactiae subsp. dysgalactiae, with this transfer possibly contributing to host adaptation. Population structure among isolates obtained from Europe and USA [bovine = 56, canine = 26, and feline = 1] was explored. Ribotyping of all isolates and multi locus sequence typing (MLST of a subset of the isolates (n = 45 detected significant differentiation between bovine and canine isolates (Fisher exact test: P = 0.0000 [ribotypes], P = 0.0030 [sequence types], suggesting possible host adaptation of some genotypes. Concurrently, the ancestral clonal complex (54% of isolates occurred in many tissue types, all hosts, and all geographic locations suggesting the possibility of a wide and diverse niche. Conclusion This study provides evidence highlighting the importance of LGT in the evolution of the bacteria S. canis, specifically, its possible role in host adaptation and acquisition of virulence factors. Furthermore, recent LGT detected between S. canis and human

Genome characterization and population genetic structure of the zoonotic pathogen, Streptococcus canis.

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Richards, Vincent P; Zadoks, Ruth N; Pavinski Bitar, Paulina D; Lefébure, Tristan; Lang, Ping; Werner, Brenda; Tikofsky, Linda; Moroni, Paolo; Stanhope, Michael J

2012-12-18

Streptococcus canis is an important opportunistic pathogen of dogs and cats that can also infect a wide range of additional mammals including cows where it can cause mastitis. It is also an emerging human pathogen. Here we provide characterization of the first genome sequence for this species, strain FSL S3-227 (milk isolate from a cow with an intra-mammary infection). A diverse array of putative virulence factors was encoded by the S. canis FSL S3-227 genome. Approximately 75% of these gene sequences were homologous to known Streptococcal virulence factors involved in invasion, evasion, and colonization. Present in the genome are multiple potentially mobile genetic elements (MGEs) [plasmid, phage, integrative conjugative element (ICE)] and comparison to other species provided convincing evidence for lateral gene transfer (LGT) between S. canis and two additional bovine mastitis causing pathogens (Streptococcus agalactiae, and Streptococcus dysgalactiae subsp. dysgalactiae), with this transfer possibly contributing to host adaptation. Population structure among isolates obtained from Europe and USA [bovine = 56, canine = 26, and feline = 1] was explored. Ribotyping of all isolates and multi locus sequence typing (MLST) of a subset of the isolates (n = 45) detected significant differentiation between bovine and canine isolates (Fisher exact test: P = 0.0000 [ribotypes], P = 0.0030 [sequence types]), suggesting possible host adaptation of some genotypes. Concurrently, the ancestral clonal complex (54% of isolates) occurred in many tissue types, all hosts, and all geographic locations suggesting the possibility of a wide and diverse niche. This study provides evidence highlighting the importance of LGT in the evolution of the bacteria S. canis, specifically, its possible role in host adaptation and acquisition of virulence factors. Furthermore, recent LGT detected between S. canis and human bacteria (Streptococcus urinalis) is cause for concern

Genome characterization and population genetic structure of the zoonotic pathogen, Streptococcus canis

Science.gov (United States)

2012-01-01

Background Streptococcus canis is an important opportunistic pathogen of dogs and cats that can also infect a wide range of additional mammals including cows where it can cause mastitis. It is also an emerging human pathogen. Results Here we provide characterization of the first genome sequence for this species, strain FSL S3-227 (milk isolate from a cow with an intra-mammary infection). A diverse array of putative virulence factors was encoded by the S. canis FSL S3-227 genome. Approximately 75% of these gene sequences were homologous to known Streptococcal virulence factors involved in invasion, evasion, and colonization. Present in the genome are multiple potentially mobile genetic elements (MGEs) [plasmid, phage, integrative conjugative element (ICE)] and comparison to other species provided convincing evidence for lateral gene transfer (LGT) between S. canis and two additional bovine mastitis causing pathogens (Streptococcus agalactiae, and Streptococcus dysgalactiae subsp. dysgalactiae), with this transfer possibly contributing to host adaptation. Population structure among isolates obtained from Europe and USA [bovine = 56, canine = 26, and feline = 1] was explored. Ribotyping of all isolates and multi locus sequence typing (MLST) of a subset of the isolates (n = 45) detected significant differentiation between bovine and canine isolates (Fisher exact test: P = 0.0000 [ribotypes], P = 0.0030 [sequence types]), suggesting possible host adaptation of some genotypes. Concurrently, the ancestral clonal complex (54% of isolates) occurred in many tissue types, all hosts, and all geographic locations suggesting the possibility of a wide and diverse niche. Conclusion This study provides evidence highlighting the importance of LGT in the evolution of the bacteria S. canis, specifically, its possible role in host adaptation and acquisition of virulence factors. Furthermore, recent LGT detected between S. canis and human bacteria (Streptococcus

Streptococcus ovuberis sp. nov., isolated from a subcutaneous abscess in the udder of a sheep.

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Zamora, Leydis; Pérez-Sancho, Marta; Fernández-Garayzábal, Jose Francisco; Orden, Jose Antonio; Domínguez-Bernal, Gustavo; de la Fuente, Ricardo; Domínguez, Lucas; Vela, Ana Isabel

2017-11-01

One unidentified, Gram-stain-positive, catalase-negative coccus-shaped organism was recovered from a subcutaneous abscess of the udder of a sheep and subjected to a polyphasic taxonomic analysis. Based on cellular morphology and biochemical criteria, the isolate was tentatively assigned to the genus Streptococcus, although the organism did not appear to match any recognized species. 16S rRNA gene sequence comparison studies confirmed its identification as a member of the genus Streptococcus and showed that the nearest phylogenetic relatives of the unknown coccus corresponded to Streptococcus moroccensis and Streptococcus cameli (95.9 % 16S rRNA gene sequence similarity). The sodA sequence analysis showed less than 89.3 % sequence similarity with the currently recognized species of the genus Streptococcus. The novel bacterial isolate was distinguished from close relatives of the genus Streptococcusby using biochemical tests. A mass spectrometry profile was also obtained for the novel isolate using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be classified as a representative of a novel species of the genus Streptococcus, Streptococcus ovuberis sp. nov. The type strain of Streptococcus ovuberissp. nov. is VB15-00779 T (=CECT 9179 T =CCUG 69612 T ).

Vaccination against group B streptococcus.

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Heath, Paul T; Feldman, Robert G

2005-04-01

Streptococcus agalactiae (Group B streptococcus) is an important cause of disease in infants, pregnant women, the elderly and in immunosuppressed adults. An effective vaccine is likely to prevent the majority of infant disease (both early and late onset), as well as Group B streptococcus-related stillbirths and prematurity, to avoid the current real and theoretical limitations of intrapartum antibiotic prophylaxis, and to be cost effective. The optimal time to administer such a vaccine would be in the third trimester of pregnancy. The main limitations on the production of a Group B streptococcus vaccine are not technical or scientific, but regulatory and legal. A number of candidates including capsular conjugate vaccines using traditional carrier proteins such as tetanus toxoid and mutant diphtheria toxin CRM197, as well as Group B streptococcus-specific proteins such as C5a peptidase, protein vaccines using one or more Group B streptococcus surface proteins and mucosal vaccines, have the potential to be successful vaccines. The capsular conjugate vaccines using tetanus and CRM197 carrier proteins are the most advanced candidates, having already completed Phase II human studies including use in the target population of pregnant women (tetanus toxoid conjugate), however, no definitive protein conjugates have yet been trialed. However, unless the regulatory environment is changed specifically to allow the development of a Group B streptococcus vaccine, it is unlikely that one will ever reach the market.

Species identification of Streptococcus bovis group isolates causing bacteremia

DEFF Research Database (Denmark)

Agergaard, Charlotte N; Knudsen, Elisa; Dargis, Rimtas

2017-01-01

This study compared two MALDI-TOF MS systems (Biotyper and VITEK MS) on clinical Streptococcus bovis group isolates (n=66). The VITEK MS gave fewer misidentifications and a higher rate of correct identifications than the Biotyper. Only the identification of S. lutetiensis by the VITEK MS was reli......This study compared two MALDI-TOF MS systems (Biotyper and VITEK MS) on clinical Streptococcus bovis group isolates (n=66). The VITEK MS gave fewer misidentifications and a higher rate of correct identifications than the Biotyper. Only the identification of S. lutetiensis by the VITEK MS...

Isolation of Arcobacter spp from the milk of dairy cows in Brazil Isolamento de Arcobacter spp do leite de vacas leiteiras no Brasil

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Celso Pianta

2007-02-01

Full Text Available Bacteriologic examinations were performed on 188 milk samples collected from cows from 11 farms for diagnosis of mastitis in three cities of Rio Grande do Sul, Brazil. Among the common causes of mastitis, the most frequent isolates were Staphylococcus aureus, followed by Corynebacterium sp, Streptococcus uberis, Streptococcus dysgalactiae and Streptococcus agalactiae. Bacteriologic examination of 32 milk samples from one farm didn't show bacteria known as common etiologic agent of mastitis. Six samples of Arcobacter spp typed by genotypic tests as Arcobacter cryaerophilus (five strains and Arcobacter butzleri (one strain were isolated from cows' milk of that farm. It is reported the isolation of Arcobacter species from the milk of cows in absence of clinical signs of mastitis. This is the first report of the detection of the microorganisms in the milk of dairy cows in Brazil. No previous reports are known from other countries.Foram realizados exames bacteriológicos em 188 amostras de leite colhidas de vacas de 11 propriedades leiteiras para diagnóstico de mastite, em três municípios no Rio Grande do Sul, Brasil. Entre as causas comuns de mastite, os isolados mais freqüentes foram Staphylococcus aureus, seguido de Corynebacterium sp, Streptococcus uberis, Streptococcus dysgalactiae e Streptococcus agalactiae. O exame bacteriológico realizado em 32 amostras de leite de vacas de uma propriedade não demonstrou a presença de bactérias conhecidas como causadoras de mastite. Foram isoladas do leite de vacas desta propriedade seis amostras de Arcobacter spp, classificadas por testes moleculares como Arcobacter cryaerophilus (cinco amostras e Arcobacter butzleri (uma amostra. É relatado o isolamento de espécies de Arcobacter do leite de vacas na ausência de sinais clínicos de mastite. Este é o primeiro relato da detecção dos microorganismos no leite de vacas leiteiras no Brasil.

Genital infections and reproductive complications associated with Trichomonas vaginalis, Neisseria gonorrhoeae, and Streptococcus agalactiae in women of Qom, central Iran

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Mahmoud Nateghi Rostam

2017-07-01

Full Text Available Background: Trichomonas vaginalis (T.vaginalis and Neisseria gonorrhoeae (N.gonorrhoeae are two most common non-viral sexually transmitted infections in the world. No data are available regarding the epidemiology of genital infections in women of Qom, central Iran. Objective: Epidemiological investigation of sexually transmitted infections in genital specimens of women referred to the referral gynecology hospital in Qom, central Iran. Materials and Methods: Genital swab specimens were collected from women volunteers and used for identification of bacterial and protozoal infections by conventional microbial diagnostics, porA pseudo gene LightCycler® real-time PCR (for N.gonorrhoeae and ITS-PCR (for T.vaginalis. Results: Of 420 volunteers, 277 (65.9% had genital signs/symptoms, including 38.3% malodorous discharge, 37.9% dyspareunia, and 54.8% abdominal pain. Totally, 2 isolates of Streptococcus agalactiae were identified. Five specimens (1.2% in Thayer-Martin culture and 17 (4.1% in real-time PCR were identified as N.gonorrhoeae. Fifty-four specimens (12.9% in wet mount, 64 (15.2% in Dorset’s culture, and 81 (19.3% in ITS-PCR showed positive results for T.vaginalis. Five mixed infections of T.vaginalis+ N.gonorrhoeae were found. The risk of T.vaginalis infection was increased in women with low-birth-weight (p=0.00; OR=43.29, history of abortion (p=0.00; OR=91.84, and premature rupture of membranes (PROM (p=0.00; OR=21.75. The probability of finding nuclear leukocytes (p=0.00; OR=43.34 in vaginal smear was higher in T.vaginalis infection. Conclusion: The significant prevalence of trichomoniasis and gonorrhea emphasizes the need for accurate diagnosis and effective surveillance to prevent serious reproductive complications in women.

Streptococcus didelphis sp. nov., a streptococcus with marked catalase activity isolated from opossums (Didelphis virginiana) with suppurative dermatitis and liver fibrosis.

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Rurangirwa, F R; Teitzel, C A; Cui, J; French, D M; McDonough, P L; Besser, T

2000-03-01

beta-Haemolytic, catalase-positive, Gram-positive cocci that formed chains in broth media but did not react with Lancefield group antisera were isolated from skin lesions, spleen, liver and lungs of nine opossums, including eight from a research colony and one from a wildlife rehabilitation organization. The isolates had vigorous catalase activity that was retained on initial passage on non-blood-containing media, but this activity was lost in subsequent passages. The use of standard phenotypic tests did not lead to satisfactory identification of these organisms beyond the genus level, even if the aberrant catalase reaction was not considered. The 16S rRNA gene sequence of the isolates was most similar (96%) to Streptococcus dysgalactiae, but distinct from that species as 16S rRNA gene similarity of different strains of S. dysgalactiae was > 99%. Characterization of biochemical reactions and cell-wall fatty acid profiles also revealed significant differences between the opossum isolates and all other known Streptococcus spp., thus it is proposed as a new species with the name Streptococcus didelphis, sp. nov. The type strain is ATCC 700828T.

Streptococcus himalayensis sp. nov., isolated from the respiratory tract of Marmota himalayana.

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Niu, Lina; Lu, Shan; Lai, Xin-He; Hu, Shoukui; Chen, Cuixia; Zhang, Gui; Yang, Jing; Jin, Dong; Wang, Yi; Lan, Ruiting; Lu, Gang; Xie, Yingping; Ye, Changyun; Xu, Jianguo

2017-02-01

Five strains of Gram-positive-staining, catalase-negative, coccus-shaped, chain-forming organisms isolated separately from the respiratory tracts of five Marmota himalayana animals in the Qinghai-Tibet Plateau of China were subjected to phenotypic and molecular taxonomic analyses. Comparative analysis of the 16S rRNA gene indicated that these singular organisms represent a new member of the genus Streptococcus, being phylogenetically closest to Streptococcus marmotae DSM 101995T (98.4 % similarity). The groEL, sodA and rpoB sequence analysis showed interspecies similarity values between HTS2T and Streptococcus. marmotae DSM 101995T, its closest phylogenetic relative based on 16S rRNA gene sequences, of 98.2, 78.8 and 93.7 %, respectively. A whole-genome phylogenetic tree built from 82 core genes of genomes from 16 species of the genus Streptococcus validated that HTS2T forms a distinct subline and exhibits specific phylogenetic affinity with S. marmotae. In silico DNA-DNA hybridization of HTS2T showed an estimated DNA reassociation value of 40.5 % with Streptococcus. marmotae DSM 101995T. On the basis of their phenotypic characteristics and phylogenetic findings, it is proposed that the five isolates be classified as representatives of a novel species of the genus Streptococcus, Streptococcus himalayensis sp. nov. The type strain is HTS2T (=DSM 101997T=CGMCC 1.15533T). The genome of Streptococcus himalayensis sp. nov. strain HTS2T contains 2195 genes with a size of 2 275 471 bp and a mean DNA G+C content of 41.3 mol%.

Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections.

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Shewmaker, P L; Whitney, A M; Humrighouse, B W

2016-03-01

Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324(T), 97.9% similarity to S. canis ATCC 43496(T), and 97.8% similarity to S. ictaluri ATCC BAA-1300(T). A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844(T) = CCUG 67100(T) = LMG 28801(T). Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Effect of Bacteriocin-like Inhibitory Substances Produced by Vaginal ...

African Journals Online (AJOL)

Reduction of vaginal Lactobacillus population leads to overgrowth of opportunistic organisms such as Streptococcus agalactiae (Group B Streptococcus, GBS), which causes life threatening neonatal infections. The activities of bacteriocin-like inhibitory substances (BLIS) produced by Lactobacillus species isolated from the ...

Streptococcus azizii sp. nov., isolated from naïve weanling mice.

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Shewmaker, Patricia Lynn; Whitney, Anne M; Gulvik, Christopher A; Lipman, Neil S

2017-12-01

Three isolates of a previously reported novel catalase-negative, Gram-stain-positive, coccoid, alpha-haemolytic, Streptococcus species that were associated with meningoencephalitis in naïve weanling mice were further evaluated to confirm their taxonomic status and to determine additional phenotypic and molecular characteristics. Comparative 16S rRNA gene sequence analysis showed nearly identical intra-species sequence similarity (≥99.9 %), and revealed the closest phylogenetically related species, Streptococcus acidominimus and Streptococcuscuniculi, with 97.0 and 97.5 % sequence similarity, respectively. The rpoB, sodA and recN genes were identical for the three isolates and were 87.6, 85.7 and 82.5 % similar to S. acidominimus and 89.7, 86.2 and 80.7 % similar to S. cuniculi, respectively. In silico DNA-DNA hybridization analyses of mouse isolate 12-5202 T against S. acidominimus CCUG 27296 T and S. cuniculi CCUG 65085 T produced estimated values of 26.4 and 25.7 % relatedness, and the calculated average nucleotide identity values were 81.9 and 81.7, respectively. These data confirm the taxonomic status of 12-5202 T as a distinct Streptococcus species, and we formally propose the type strain, Streptococcusazizii 12-5202 T (=CCUG 69378 T =DSM 103678 T ). The genome of Streptococcus azizii sp. nov. 12-5202 T contains 2062 total genes with a size of 2.34 Mbp, and an average G+C content of 42.76 mol%.

Liamocin oil from Aureobasidium pullulans has antibacterial activity with specificity for species of Streptococcus

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Liamocin oil from Aureobasidium pullulans NRRL 50380 was tested for antibacterial activity. Liamocins inhibited growth of Streptococcus agalactiae, S. uberis, S. mitis, S. infantarius, and S. mutans, with minimum inhibitory concentrations from 20 'g/ml to 78 'g/ml. Enterococcus faecalis was less sus...

Antibiotic susceptibility of periodontal Streptococcus constellatus and Streptococcus intermedius clinical isolates.

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Rams, Thomas E; Feik, Diane; Mortensen, Joel E; Degener, John E; van Winkelhoff, Arie J

2014-12-01

Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections. Because systemic antibiotics are often used in these clinical situations, and little is known of the antibiotic susceptibility of subgingival isolates of these two bacterial species, this study determined the in vitro susceptibility to six antibiotics of fresh S. constellatus and S. intermedius clinical isolates from human periodontitis lesions. A total of 33 S. constellatus and 17 S. intermedius subgingival strains, each recovered from separate patients with severe chronic periodontitis (n = 50) before treatment, were subjected to antibiotic gradient strip susceptibility testing with amoxicillin, azithromycin, clindamycin, ciprofloxacin, and doxycycline on blood-supplemented Mueller-Hinton agar and to the inhibitory effects of metronidazole at 16 mg/L in an enriched Brucella blood agar dilution assay. Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing interpretative standards were used to assess the results. Clindamycin was the most active antibiotic against S. constellatus (minimum inhibitory concentration at 90% [MIC90] 0.25 mg/L), and amoxicillin was most active against S. intermedius (MIC90 0.125 mg/L). A total of 30% of the S. constellatus and S. intermedius clinical isolates were resistant in vitro to doxycycline, 98% were only intermediate in susceptibility to ciprofloxacin, and 90% were resistant to metronidazole at 16 mg/L. Subgingival S. constellatus and S. intermedius exhibited variable antibiotic susceptibility profiles, potentially complicating empirical selection of periodontitis antibiotic therapy in patients who are species positive.

Quimioprofilaxis para evitar la colonización materna por estreptococo grupo B: consecuencias de no adoptar la recomendación internacional Maternal chemoprophylaxis against group B Streptococcus colonization: the consequences of not adopting the international recommendation

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Jesús Reyna-Figueroa

2008-04-01

Full Text Available OBJETIVO: Conocer el criterio para la quimioprofilaxis en mujeres embarazadas colonizadas con Streptococcus agalactiae (SGB y las repercusiones de la infección en México. MATERIAL Y MÉTODOS: Se identificó a mujeres embarazadas con SGB mediante el cultivo cervicovaginal y/o urinario en una revisión de cinco años. Se formaron dos grupos: con uso de quimioprofilaxis, el primero, y sin uso de la misma, el segundo. Con base en la utilización de la prueba de ji cuadrada se determinó la diferencia de proporciones. La aproximación de ji cuadrada para la distribución de Poisson comparó los promedios de la infección neonatal. RESULTADOS: Se notificaron 274 cultivos positivos para SGB en 261 pacientes; 165 (60.2% cervicovaginales, 109 (39.7% urinarios, y en 13 pacientes (4.7% se obtuvo resultado positivo en ambos. De las 261 pacientes, 53 (5.6% recibieron profilaxis intraparto (pOBJECTIVE: To know the criteria which determine the chemoprophylaxis on pregnant women colonized by Streptococcus agalactiae (GBS and the impact in our environment. MATERIAL AND METHODS: A retrospective analysis, identifying pregnant women with isolation of Streptococcus agalactiae on screening cultures, cervical swabs and urine culture. Two groups were analyzed, group 1 received chemoprophylaxis, and group 2 without chemoprophylaxis. Chi square was used to asses the difference between proportions. Chi square approximation to Poisson distribution was used to compare the means of neonatal infection. RESULTS: A total of 274 cultures were reported with GBS isolation, on 261 patients; 165 (60.2% cervical swabs, 109 (39.7% urine culture and 13 patients from 274 (4.7% had positive culture on both specimens. Of this 261 patients, 53 (5.6% received chemoprophylaxis during labor (p<0.05. The CDC criteria were followed accuracy on 29.2%. CONCLUSIONS: There have not been established criteria for screening colonization by GBS in Mexican pregnant women.

SUSCEPTIBILITY OF RESPIRATORY ISOLATES OF STREPTOCOCCUS PNEUMONIAE ISOLATED FROM CHILDREN HOSPITALIZED IN THE CLINICAL CENTER NIS.

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Dinić, Marina M; Mladenović Antić, Snezana; Kocić, Branislava; Stanković Dordević, Dobrila; Vrbić, Miodrag; Bogdanović, Milena

2016-01-01

Streptococcus pneumoniae is one of the most common causes of respiratory infections. The aim was to study the susceptibility to antimicrobial agents of respiratory isolates ofStreptococcus pneumoniae obtained from hospitalized children. A total of 190 respiratory pneumococcal isolates obtained from children aged from 0 to 14 years were isolated and identified by using standard microbiological methods. Susceptibility to oxacillin, erythromycin, clindamycin, tetracycline, cotrimoxazole, ofloxacin and rifampicin was tested by disc diffusion method. Minimal inhibitory concentrations for amoxicillin and ceftriaxone were determined by means of E test. The macrolide-resistant phenotype was detected by double disc diffusion test. All tested isolates were susceptible to amoxicillin and ceftriaxone. The minimal amoxicillin concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.50 microg/ml and 1.0 microg/ml, respectively and the minimal ceftriaxone concentration inhibiting the growth of 50% of isolates and of 90% of isolates was 0.25 microg/ml and 0.50 microg/ml, respectively. Susceptibility to erythromycin and clindamycin was observed in 21.6% and 29.47% of isolates, respectively. The resistence to macrolides-M phenotype was detected in 10.07% of isolates and constitutive macrolide-lincosamide-streptogramin phenotype (constitutive MLS phenotype) was found in 89.93% of isolates. All tested isolates were susceptible to ofloxacin and rifampicin. Amoxicillin could be the therapy of choice in pediatric practice. The macrolides should not be recommended for the empirical therapy of pneumococcal respiratory tract infection in our local area.

Comparison of different sampling techniques and of different culture methods for detection of group B streptococcus carriage in pregnant women

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Verhelst Rita

2010-09-01

Full Text Available Abstract Background Streptococcus agalactiae (group B streptococcus; GBS is a significant cause of perinatal and neonatal infections worldwide. To detect GBS colonization in pregnant women, the CDC recommends isolation of the bacterium from vaginal and anorectal swab samples by growth in a selective enrichment medium, such as Lim broth (Todd-Hewitt broth supplemented with selective antibiotics, followed by subculture on sheep blood agar. However, this procedure may require 48 h to complete. We compared different sampling and culture techniques for the detection of GBS. Methods A total of 300 swabs was taken from 100 pregnant women at 35-37 weeks of gestation. For each subject, one rectovaginal, one vaginal and one rectal ESwab were collected. Plating onto Columbia CNA agar (CNA, group B streptococcus differential agar (GBSDA (Granada Medium and chromID Strepto B agar (CA, with and without Lim broth enrichment, were compared. The isolates were confirmed as S. agalactiae using the CAMP test on blood agar and by molecular identification with tDNA-PCR or by 16S rRNA gene sequence determination. Results The overall GBS colonization rate was 22%. GBS positivity for rectovaginal sampling (100% was significantly higher than detection on the basis of vaginal sampling (50%, but not significantly higher than for rectal sampling (82%. Direct plating of the rectovaginal swab on CNA, GBSDA and CA resulted in detection of 59, 91 and 95% of the carriers, respectively, whereas subculturing of Lim broth yielded 77, 95 and 100% positivity, respectively. Lim broth enrichment enabled the detection of only one additional GBS positive subject. There was no significant difference between GBSDA and CA, whereas both were more sensitive than CNA. Direct culture onto GBSDA or CA (91 and 95% detected more carriers than Lim broth enrichment and subculture onto CNA (77%. One false negative isolate was observed on GBSDA, and three false positives on CA. Conclusions In

Trends in udder health and emerging mastitogenic pathogens in South African dairy herds

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I.M. Petzer

2009-05-01

Full Text Available The aim of this study was to retrospectively analyse the results of milk samples obtained from South African dairy herds during the period 1996 to April 2007 in order to identify possible trends in isolates of microorganisms and their pathogenicity under field conditions. Milk samples were obtained from 7 of the 9 provinces in South Africa where there are low numbers of dairy cows. Although there is scientific limitation to a country wide survey, such as the variation in herd size, management skills, parity, milk yield, milking frequency and other parameters, the size of this database helps to give a fair indication of general udder health in South Africa. Cytology and routine bacteriology were performed on 379 000 milk samples of lactating cows and bacteriology on 11 946 samples from non-lactating cows. According to the results obtained, mastitis did not decrease in South Africa over the test period. The prevalence of mastitis and teat canal infection was lowest in 2002. Mastitis and teat canal infection increased from 2002 to 2006 from 8.1 % and 24.1 % to 15.4 and 30.0 % respectively. The percentage of mastitogenic pathogens isolated from cows over these years also varied. Previously unknown or almost eradicated mastitogenic pathogens such as αβ haemolytic Staphylococcus aureus which is thought to be of human origin, Streptococcus agalactiae and Enterococcus canis were responsible for numerous mastitis outbreaks seen in the test samples. Coagulase-negative staphylococci were the most frequently isolated bacteria in milk samples from both lactating and dry cows, followed by Staphylococcus aureus and Streptococcus agalactiae. Although Staphylococcus aureus remained the principal mastitogenic pathogen in South Africa, owing to its chronic nature and resultant economic losses, most cases of mastitis were caused by coagulase-negative staphylococci. This finding increases the importance of coagulase-negative staphylococci (formerly described as a

Gene repertoire evolution of Streptococcus pyogenes inferred from phylogenomic analysis with Streptococcus canis and Streptococcus dysgalactiae.

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Tristan Lefébure

Full Text Available Streptococcus pyogenes, is an important human pathogen classified within the pyogenic group of streptococci, exclusively adapted to the human host. Our goal was to employ a comparative evolutionary approach to better understand the genomic events concomitant with S. pyogenes human adaptation. As part of ascertaining these events, we sequenced the genome of one of the potential sister species, the agricultural pathogen S. canis, and combined it in a comparative genomics reconciliation analysis with two other closely related species, Streptococcus dysgalactiae and Streptococcus equi, to determine the genes that were gained and lost during S. pyogenes evolution. Genome wide phylogenetic analyses involving 15 Streptococcus species provided convincing support for a clade of S. equi, S. pyogenes, S. dysgalactiae, and S. canis and suggested that the most likely S. pyogenes sister species was S. dysgalactiae. The reconciliation analysis identified 113 genes that were gained on the lineage leading to S. pyogenes. Almost half (46% of these gained genes were phage associated and 14 showed significant matches to experimentally verified bacteria virulence factors. Subsequent to the origin of S. pyogenes, over half of the phage associated genes were involved in 90 different LGT events, mostly involving different strains of S. pyogenes, but with a high proportion involving the horse specific pathogen S. equi subsp. equi, with the directionality almost exclusively (86% in the S. pyogenes to S. equi direction. Streptococcus agalactiae appears to have played an important role in the evolution of S. pyogenes with a high proportion of LGTs originating from this species. Overall the analysis suggests that S. pyogenes adaptation to the human host was achieved in part by (i the integration of new virulence factors (e.g. speB, and the sal locus and (ii the construction of new regulation networks (e.g. rgg, and to some extent speB.

Isolation and identification of bacterial causes of clinical mastitis in cattle in Sulaimania region

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S. A. Hussein

2008-01-01

Full Text Available A total of 51 cases of bovine clinical mastitis in Sulaimani district were investigated for their bacteriological causative agents; 76 milk samples were cultured on primary and selective media and the isolated bacteria were tested for their susceptibility to antimicrobial agents used in commercial intramammary infusion products. Eighty two bacterial isolates were obtained and further identified using biochemical tests. Escherichia coli was the most common bacteria followed by Staphylococcus aureus, Streptococcus agalactia and coagulase–negative staphylococci. Two other bacterial species (Pseudomonas aeruginosa and Streptococcucs uberis were also isolated but in a lower proportion. Antibacterial susceptibility testing showed that the use of florfenicol, cephalexin and gentamicin may be useful for the treatment of clinical mastitis cases in cows.

Streptococcus suis, an emerging drug-resistant animal and human pathogen

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Claudio ePalmieri

2011-11-01

Full Text Available Streptococcus suis, a major porcine pathogen, has been receiving growing attention not only for its role in severe and increasingly reported infections in humans, but also for its involvement in drug resistance. Recent studies and the analysis of sequenced genomes have been providing important insights into the S. suis resistome, and have resulted in the identification of resistance determinants for tetracyclines, macrolides, aminoglycosides, chloramphenicol, antifolate drugs, streptothricin, and cadmium salts. Resistance gene-carrying genetic elements described so far include integrative and conjugative elements, transposons, genomic islands, phages, and chimeric elements. Some of these elements are similar to those reported in major streptococcal pathogens such as Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus agalactiae and share the same chromosomal insertion sites. The available information strongly suggests that S. suis is an important antibiotic resistance reservoir that can contribute to the spread of resistance genes to the above-mentioned streptococci. S. suis is thus a paradigmatic example of possible intersections between animal and human resistomes.

Mastitogenic bacteria isolated from dairy cows in Kenya and their antimicrobial sensitivity

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George K. Gitau

2014-02-01

Full Text Available There is limited epidemiological knowledge on udder health in Kenyan dairy cattle that would aid in a pro-active approach towards mastitis prevention. The study objectives were: (1 to investigate the prevalence and distribution of clinical and subclinical mastitis in dairy cattle in Mukurwe-ini and Nakuru Districts, Kenya, and (2 to determine the antibacterial sensitivity of the organisms causing bovine mastitis in these districts. The study involved field-screening of milk samples from 241 dairy cows on 128 farms by use of the California Mastitis Test (CMT and, if CMT-positive, followed by bacteriological culture of the major causative agents and their respective antibiotic sensitivity to eight commonly used antibiotics. All participating farms were visited twice during the study period. The results obtained during the first and second visits showed the prevalence of clinical mastitis to be very low: 0.9% and 0.5%, respectively; 56.0% and 65.0% of cows were CMT-positive on at least one quarter and 49.6% and 58.7% of cows were culture-positive, respectively. There was no significant difference in mastitis prevalence between Nakuru and Mukurwe-ini districts (p > 0.10. Staphylococcus aureus was isolated in 68.0% and 77.0% of samples during the first and second visits, respectively. Other frequently isolated agents included Streptococcus agalactiae, and other Streptococcus spp., S. aureus and S. agalactiae were most sensitive to gentamycin and norfloxacin, and least sensitive to cotrimazole and ampicillin. Knowing the prevalence of mastitogenic organisms and their antibiotic sensitivities could improve treatment efficacy and cow longevity.

Resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae and S. agalatiae Ib is heritable but not correlated

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Tilapia (Oreochromis sp.) are an important source of protein with an ecomonic value approaching US $8 billion yearly. Streptococcal disease, caused by Streptococcus iniae and S. agalactiae (both Gram positive bacteria), is an emerging or re-emerging disease negatively affecting tilapia aquaculture w...

Antimicrobial activity of pure platelet-rich plasma against microorganisms isolated from oral cavity.

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Drago, Lorenzo; Bortolin, Monica; Vassena, Christian; Taschieri, Silvio; Del Fabbro, Massimo

2013-02-25

Autologous platelet concentrates (PCs) have been extensively used in a variety of medical fields to promote soft and hard tissue regeneration. The significance behind their use lies in the abundance of growth factors in platelets α-granules that promotes wound healing. In addition, antibacterial properties of PCs against various bacteria have been recently pointed out. In this study, the antimicrobial effect of pure platelet-rich plasma (P-PRP) was evaluated against oral cavity microorganisms such as Enterococcus faecalis, Candida albicans, Streptococcus agalactiae, Streptococcus oralis and Pseudomonas aeruginosa. Blood samples were obtained from 17 patients who underwent oral surgery procedures involving the use of P-PRP. The antibacterial activity of P-PRP, evaluated as the minimum inhibitory concentration (MIC), was determined through the microdilution twofold serial method. P-PRP inhibited the growth of Enterococcus faecalis, Candida albicans, Streptococcus agalactiae and Streptococcus oralis, but not of Pseudomonas aeruginosa strains. P-PRP is a potentially useful substance in the fight against postoperative infections. This might represent a valuable property in adjunct to the enhancement of tissue regeneration.

Modeling Group B Streptococcus and Blood-Brain Barrier Interaction by Using Induced Pluripotent Stem Cell-Derived Brain Endothelial Cells

OpenAIRE

Kim, Brandon J.; Bee, Olivia B.; McDonagh, Maura A.; Stebbins, Matthew J.; Palecek, Sean P.; Doran, Kelly S.; Shusta, Eric V.

2017-01-01

ABSTRACT Bacterial meningitis is a serious infection of the central nervous system (CNS) that occurs after bacteria interact with and penetrate the blood-brain barrier (BBB). The BBB is comprised of highly specialized brain microvascular endothelial cells (BMECs) that function to separate the circulation from the CNS and act as a formidable barrier for toxins and pathogens. Certain bacteria, such as Streptococcus agalactiae (group B Streptococcus [GBS]), possess the ability to interact with a...

Prevalência de colonização por Streptococcus agalactiae em gestantes atendidas em maternidade do Ceará, no Brasil, correlacionando com os resultados perinatais Prevalence of the colonization by Streptococcus agalactiae in pregnant women from a maternity in Ceará, Brazil, correlating with perinatal outcomes

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José Juvenal Linhares

2011-12-01

Full Text Available OBJETIVO: Analisar a prevalência de Streptococcus agalactiae, um estreptococo do Grupo B, em gestantes e seus possíveis fatores de risco, bem como o impacto perinatal e a suscetibilidade antimicrobiana das colonizadas. MÉTODOS: Foram avaliadas 213 gestantes a partir de 20 semanas de gestação, independente dos fatores de risco, atendidas em um hospital-escola terciário da zona Norte do Estado de Ceará, no Brasil. O cálculo do tamanho amostral ocorreu por conveniência. Foi utilizada técnica do swab estéril único para coleta de secreção das regiões vaginal e perianal. As amostras recém-obtidas eram armazenadas em meio de transporte Stuart e, no laboratório, inoculadas em meio seletivo Todd-Hewitt adicionado de gentamicina (8 ug/mL e ácido nalidíxico (15 ug/mL, com posterior subcultivo em placas em ágar-sangue. Nos materiais eram realizados teste de Gram, catalase com peróxido de oxigênio e CAMP (Christie, Atkins, Munch-Petersen, sendo confirmados sorologicamente com Streptococcal Grouping Kit, Oxoid®. As positivas foram submetidas a testes de suscetibilidade antimicrobiana. Foram também avaliadas variáveis socioeconômicas, reprodutivas, clínico-obstétricas e neonatais. Os dados foram analisados utilizando o programa Epi-Info 6.04. RESULTADOS: A prevalência de colonização encontrada foi de 9,8% pelo teste de CAMP, embora apenas 4,2% pelo sorológico. O único fator de proteção observado foi cor da pele branca (p=0,01, 0.45>OR>0.94, IC95%. Não foi observada diferença de prevalência do estreptococo do Grupo B com outras variáveis reprodutivas ou obstétricas. Ocorreu infecção em apenas um dos recém-nascidos de mães colonizadas, entretanto revelou-se infecção por Pseudomonas spp. Foi encontrada resistência para ampicilina (4/9 e cefalotina (4/9, penicilina (4/9 casos, eritromicina (3/9, clindamicina (7/9 e cloranfenicol (1/9. CONCLUSÕES: A taxa de infecção foi inferior à encontrada em outros estudos

Susceptibility to antimicrobial agents among bovine mastitis pathogens isolated from North American dairy cattle, 2002-2010.

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Lindeman, Cynthia J; Portis, Ellen; Johansen, Lacie; Mullins, Lisa M; Stoltman, Gillian A

2013-09-01

Approximately 8,000 isolates of Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Staphylococcus aureus, and Escherichia coli, isolated by 25 veterinary laboratories across North America between 2002 and 2010, were tested for in vitro susceptibility to beta-lactam, macrolide, and lincosamide drugs. The minimal inhibitory concentrations (MICs) of the beta-lactam drugs remained low against most of the Gram-positive strains tested, and no substantial changes in the MIC distributions were seen over time. Of the beta-lactam antimicrobial agents tested, only ceftiofur showed good in vitro activity against E. coli. The MICs of the macrolides and lincosamides also remained low against Gram-positive mastitis pathogens. While the MIC values given by 50% of isolates (MIC50) for erythromycin and pirlimycin and the streptococci were all low (≤0.5 µg/ml), the MIC values given by 90% of isolates (MIC90) were higher and more variable, but with no apparent increase over time. Staphylococcus aureus showed little change in erythromycin susceptibility over time, but there may be a small, numerical increase in pirlimycin MIC50 and MIC90 values. Overall, the results suggest that mastitis pathogens in the United States and Canada have not shown any substantial changes in the in vitro susceptibility to beta-lactam, macrolide, and lincosamide drugs tested over the 9 years of the study.

Antibacterial activity of Iranian medicinal plants against Streptococcus iniae isolated from rainbow trout (Oncorhynchus mykiss

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Pirbalouti Ghasemi Abdollah

2011-01-01

Full Text Available Streptococcus iniae is among the major pathogens of a large number of fish species cultured in fresh and marine recirculating and net pen production systems. Ten Iranian medicinal plants were assessed for their antimicrobial activity against Streptococcus iniae isolates obtained from diseased Oncorhynchus mykiss (Salmonidae; Walbaum, 1972 collected from fish farms in Iran. The antibacterial activity of ethanol extracts of Punica granatum, Quercus branti, Glycyrrhiza glabra and essential oils of Heracleum lasiopetalum, Satureja bachtiarica, Thymus daenensis, Myrtus communis, Echinophora platyloba, Kelussia odoratissima and Stachys lavandulifolia against Steptococcus iniae was evaluated by disc diffusion and serial dilution assays. Most of the extracts and essential oils showed a relatively high antibacterial activity against Streptococcus iniae. Of the plants studied, the most active extracts were those obtained from the essential oils of Satureja bachtiarica, Echinophora platyloba, Thymus daenensis and the ethanol extract of Quercus branti. Some of the extracts were active against Streptococcus iniae. Two essential oils showed lower MIC values; Heracleum lasiopetalum (78 μg/ml and Satureja bachtiarica (39 μg/ml. The essential oil of Satureja bachtiarica could be an important source of antibacterial compounds against the Streptococcus iniae isolated from rainbow trout.

Isolation and characterization of promoter regions from Streptococcus gordonii CH1

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Vriesema, A.J.M.; Dankert, J.; Zaat, S.A.J.

1999-01-01

We aimed to identify transcription signal sequences from Streptococcus gordonii strain CH1 by random chromosomal cloning. Five genomic fragments from a Sau3A digest, which constitutively activated transcription of a promoterless spectinomycin resistance gene in this strain, were isolated and

Streptococcus pharyngis sp. nov., a novel streptococcal species isolated from the respiratory tract of wild rabbits.

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Vela, Ana I; Casas-Díaz, Encarna; Lavín, Santiago; Domínguez, Lucas; Fernández-Garayzábal, Jose F

2015-09-01

Four isolates of an unknown Gram-stain-positive, catalase-negative coccus-shaped organism, isolated from the pharynx of four wild rabbits, were characterized by phenotypic and molecular genetic methods. The micro-organisms were tentatively assigned to the genus Streptococcus based on cellular morphological and biochemical criteria, although the organisms did not appear to correspond to any species with a validly published name. Comparative 16S rRNA gene sequencing confirmed their identification as members of the genus Streptococcus, being most closely related phylogenetically to Streptococcus porcorum 682-03(T) (96.9% 16S rRNA gene sequence similarity). Analysis of rpoB and sodA gene sequences showed divergence values between the novel species and S. porcorum 682-03(T) (the closest phylogenetic relative determined from 16S rRNA gene sequences) of 18.1 and 23.9%, respectively. The novel bacterial isolate could be distinguished from the type strain of S. porcorum by several biochemical characteristics, such as the production of glycyl-tryptophan arylamidase and α-chymotrypsin, and the non-acidification of different sugars. Based on both phenotypic and phylogenetic findings, it is proposed that the unknown bacterium be assigned to a novel species of the genus Streptococcus, and named Streptococcus pharyngis sp. nov. The type strain is DICM10-00796B(T) ( = CECT 8754(T) = CCUG 66496(T)).

Antibacterial Effects of Citrus aurantium on Bacteria Isolated from Urinary Tract Infection

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Masoud Dadashi

2015-10-01

Full Text Available Background :  Emerging antibacterial resistance rates and beta-lactamase producing bacteria recovered from UTI is an increasing problem in different regions, limiting therapeutic options. Therefore, this survey consider to use the extract and essence of the citrus aurantium (which have a so many rate of planting in Iran and also survey on extract on bacteria whose cause urinary tract infections, and compare this with common antibiotics. Methods and Materials: This study was experimental design.We have been isolate the E.coli,Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae and Enterococcus faecalis from UTI and then determine of antibacterial effect of Citrus aurantium against this bacteria with subculture and put the exact diagnosis on them. Antibacterial effects of the herb extract by well diffusion assay and  nalidixic acid and Co-trimoxazol were evaluated by method of agar disc diffusion. Results:Enterococcus faecalis had 100% sensitivity against of extract,essence and Co-trimoxazole , and 80% against nalidixic acid . E.coli had 100% sensitivity against Co-trimoxazol, nalidixic acid and it was totally resistance to extract and essence.Klebsiella Pneumonie had 80% to Co-trimoxazol, 75% to nalidixic acid and resistance against extract and essence.Streptococcus agalactiae was 100% sensitivity to essence and Co-trimoxazol and 90% against nalidixic acid and shown 80% sensitivity against extract.Staphylococcus aureus MRSA shown 100% sensitivity against Co-trimoxazol and 70% sensitivity against essence, extract and nalidixic acid. Conclusion: Detection of antibiotic resistance among isolates is important in prevention and control of infections. In this study, it was shown that extracts of citrus aurantium have high antibacterial effects on gram positive bacteria compare to gram negative bacteria.

In vitro activity of 24 antimicrobial agents against Staphylococcus and Streptococcus isolated from diseased animals in Japan.

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Morioka, Ayako; Asai, Tetsuo; Ishihara, Kanako; Kojima, Akemi; Tamura, Yutaka; Takahashi, Toshio

2005-02-01

A total of 88 Staphylococcus and 61 Streptococcus isolates from diseased animals throughout Japan were examined in 2000 for the minimum inhibitory concentrations of 24 different antimicrobials by the agar dilution method standardized by the Japanese Society of Chemotherapy. The resistance rates to aminobenzylpenicillin (36.4%) and benzylpenicillin (35.2%) were high in Staphylococcus isolates, and those to oxytetracycline (45.9%) and kanamycin (21.3%) were high in Streptococcus isolates. Two isolates resistant to oxacillin harbored the mecA gene. One was Staphylococcus epidermidis derived from a pig with arthritis, and the other Staphylococcus cohnii from a head of cattle with mastitis.

Characterization of a Streptococcus suis tet(O/W/32/O)-carrying element transferable to major streptococcal pathogens.

Science.gov (United States)

Palmieri, Claudio; Magi, Gloria; Mingoia, Marina; Bagnarelli, Patrizia; Ripa, Sandro; Varaldo, Pietro E; Facinelli, Bruna

2012-09-01

Mosaic tetracycline resistance determinants are a recently discovered class of hybrids of ribosomal protection tet genes. They may show different patterns of mosaicism, but their final size has remained unaltered. Initially thought to be confined to a small group of anaerobic bacteria, mosaic tet genes were then found to be widespread. In the genus Streptococcus, a mosaic tet gene [tet(O/W/32/O)] was first discovered in Streptococcus suis, an emerging drug-resistant pig and human pathogen. In this study, we report the molecular characterization of a tet(O/W/32/O) gene-carrying mobile element from an S. suis isolate. tet(O/W/32/O) was detected, in tandem with tet(40), in a circular 14,741-bp genetic element (39.1% G+C; 17 open reading frames [ORFs] identified). The novel element, which we designated 15K, also carried the macrolide resistance determinant erm(B) and an aminoglycoside resistance four-gene cluster including aadE (streptomycin) and aphA (kanamycin). 15K appeared to be an unstable genetic element that, in the absence of recombinases, is capable of undergoing spontaneous excision under standard growth conditions. In the integrated form, 15K was found inside a 54,879-bp integrative and conjugative element (ICE) (50.5% G+C; 55 ORFs), which we designated ICESsu32457. An ∼1.3-kb segment that apparently served as the att site for excision of the unstable 15K element was identified. The novel ICE was transferable at high frequency to recipients from pathogenic Streptococcus species (S. suis, Streptococcus pyogenes, Streptococcus pneumoniae, and Streptococcus agalactiae), suggesting that the multiresistance 15K element can successfully spread within streptococcal populations.

Genetic patterns of Streptococcus uberis isolated from bovine mastitis

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Elina B Reinoso

2015-06-01

Full Text Available The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE. Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns. Different strains were found within and among herds; however, a low number of isolates within the same herd shared an identical PFGE type. No association between PFGE patterns and virulence profiles was found. However, the detection of specific strains in some herds could indicate that some strains are more virulent than others. Further research needs to be undertaken to elucidate new virulence-associated genes that might contribute to the capability of these strains to produce infection.

Isolation and partial characterization of a biosurfactant produced by Streptococcus thermophilus A

NARCIS (Netherlands)

Rodrigues, Ligia R.; Teixeira, Jose A.; van der Mei, Henny C.; Oliveira, Rosario

2006-01-01

Isolation and characterization of the surface active components from the crude biosurfactant produced by Streptococcus thermophilus A was studied. A fraction rich in glycolipids was obtained by the fractionation of crude biosurfactant using hydrophobic interaction chromatography. Molecular (by

RNA-Seq revealed the impairment of immune defence of tilapia against the infection of Streptococcus agalactiae with simulated climate warming.

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Wang, Le; Liu, Peng; Wan, Zi Yi; Huang, Shu Qing; Wen, Yan Fei; Lin, Grace; Yue, Gen Hua

2016-08-01

Global warming is one of the causes of disease outbreaks in fishes. Understanding its mechanisms is critical in aquaculture and fisheries. We used tilapia to study the effects of a high temperature on the infection of a bacterial pathogen Streptococcus agalactiae using RNA-Seq. We found that the dissolved oxygen level in water at 32 °C is lower than at 22 °C, and tilapia infected with the pathogen died more rapidly at 32 °C. The gene expression profiles showed significant differences in fish raised under different conditions. We identified 126 and 576 differentially expressed genes (DEGs) at 4 and 24 h post infection at 22 °C, respectively, whereas at 32 °C, the data were 312 and 1670, respectively. Almost all responding pathways at 22 °C were involved in the immune responses, whereas at 32 °C, the enriched pathways were not only involved in immune responses but also involved in oxygen and energy metabolisms. We identified significant signals of immunosuppression of immune responses at 32 °C. In addition, many of the enriched transcription factors and DEGs under positive selection were involved in immune responses, oxygen and/or energy metabolisms. Our results suggest that global warming could reduce the oxygen level in water and impair the defence of tilapia against bacterial infection. Copyright © 2016 Elsevier Ltd. All rights reserved.

Streptococcus oricebi sp. nov., isolated from the oral cavity of tufted capuchin.

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Saito, M; Shinozaki-Kuwahara, N; Hirasawa, M; Takada, K

2016-02-01

A Gram-stain-positive, catalase-negative, coccus-shaped organism was isolated from the oral cavity of tufted capuchin (Cebus apella). Comparative 16S rRNA gene sequence analysis suggested classification of the organism within the genus Streptococcus. Strain M8T was related most closely to Streptococcus oralis ATCC 35037T (96.17 % similarity) followed by Streptococcus massiliensis CCUG 49690T (95.90 %) based on the 16S rRNA gene. Strain M8T was related most closely to S. massiliensis CCUG 49690T (86.58 %) based on the RNA polymerase β subunit-encoding gene (rpoB), and to Streptococcus tigurinus AZ_3aT (81.26 %) followed by S. massiliensis CCUG 49690T (80.45 %) based on the 60 kDa heat-shock protein gene (groEL). The phylogenetic trees of 16S rRNA, rpoB and groEL gene sequences showed that strain M8T was most closely related to S. massiliensis. Based on phenotypic characterization as well as 16S rRNA gene and housekeeping gene (rpoB and groEL) sequence data, a novel taxon, Streptococcus oricebi sp. nov. (type strain M8T = JCM 30719T = DSM 100101T), is proposed.

Vaginal isolation of beta-haemolytic Streptococcus from bitches with and without neonatal deaths in the litters.

Science.gov (United States)

Guerrero, A E; Stornelli, M C; Jurado, S B; Giacoboni, G; Sguazza, G H; de la Sota, R L; Stornelli, M A

2018-02-18

The aim of the study was to identify beta-haemolytic streptococci in the vagina of bitches who had delivered healthy litters and bitches who had delivered litters in which neonatal deaths occurred. Fifty-one bitches divided into two groups were used. Group 1 (G1) included 28 bitches that had delivered healthy litters and group 2 (G2) included 23 bitches that had delivered puppies who died in the neonatal period. Two vaginal samples were taken, one in proestrus and the other at the end of gestation (EG). Beta-haemolytic Streptococcus (BS) was isolated from 16 bitches (57%) in G1 and from 21 bitches (91%) in G2. The bacteriological cultures, serological tests (Streptex ® ) and PCR assay allowed identification of Streptococcus canis and Streptococcus dysgalactiae in G1 and G2. Ultramicroscopic studies allowed the observation of M Protein and capsules in strains of S. dysgalactiae and S. canis in G1 and G2. The S. canis strains isolated from G2 showed thicker capsules than S. canis strains isolated from G1 (234 ± 24.2 vs 151.23 ± 28.93 nm; p  .70). All strains of beta-haemolytic Streptococcus isolated were penicillin sensitive. Penicillin was administered from EG to 5 days post-partum in 10 G2 females with isolation of BS (G2A). Saline solution was administered in eleven G2 females with isolation of BS (G2B). Ninety per cent of the puppies survived in G2A and 25% survived in G2B. Our results suggest BS is involved in canine neonatal deaths. © 2018 Blackwell Verlag GmbH.

Antibiotic Susceptibility of Periodontal Streptococcus Constellatus and Streptococcus Intermedius Clinical Isolates

NARCIS (Netherlands)

Rams, Thomas E; Feik, Diane; Mortensen, Joel E; Degener, John E; van Winkelhoff, Arie J

2014-01-01

Background: Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections.

Genetic patterns of Streptococcus uberis isolated from bovine mastitis.

Science.gov (United States)

Reinoso, Elina B; Lasagno, Mirta C; Odierno, Liliana M

2015-01-01

The aim of this study was to evaluate the genotypic relationships among 40 Streptococcus uberis isolated from bovine mastitis by using pulsed-field gel electrophoresis (PFGE). Additionally, the association between PFGE patterns and virulence profiles was investigated. The isolates exhibited 17 PFGE patterns. Different strains were found within and among herds; however, a low number of isolates within the same herd shared an identical PFGE type. No association between PFGE patterns and virulence profiles was found. However, the detection of specific strains in some herds could indicate that some strains are more virulent than others. Further research needs to be undertaken to elucidate new virulence-associated genes that might contribute to the capability of these strains to produce infection. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Streptococcus caviae sp. nov., isolated from guinea pig faecal samples.

Science.gov (United States)

Palakawong Na Ayudthaya, Susakul; Hilderink, Loes J; Oost, John van der; Vos, Willem M de; Plugge, Caroline M

2017-05-01

A novel cellobiose-degrading and lactate-producing bacterium, strain Cavy grass 6T, was isolated from faecal samples of guinea pigs (Cavia porcellus). Cells of the strain were ovalshaped, non-motile, non-spore-forming, Gram-stain-positive and facultatively anaerobic. The strain gr at 25-40 °C (optimum 37 °C) and pH 4.5-9.5 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Cavy grass 6T belongs to the genus Streptococcus with its closest relative being Streptococcus devriesei CCUG 47155T with only 96.5 % similarity. Comparing strain Cavy grass 6T and Streptococcus devriesei CCUG 47155T, average nucleotide identity and level of digital DNA-DNA hybridization dDDH were only 86.9 and 33.3 %, respectively. Housekeeping genes groEL and gyrA were different between strain Cavy grass 6T and other streptococci. The G+C content of strain Cavy grass 6T was 42.6±0.3 mol%. The major (>10 %) cellular fatty acids of strain Cavy grass 6T were C16:0, C20 : 1ω9c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). Strain Cavy grass 6T ferment a range of plant mono- and disaccharides as well as polymeric carbohydrates, including cellobiose, dulcitol, d-glucose, maltose, raffinose, sucrose, l-sorbose, trehalose, inulin and dried grass extract, to lactate, formate, acetate and ethanol. Based on phylogenetic and physiological characteristics, Cavy grass 6T can be distinguished from other members of the genus Streptococcus. Therefore, a novel species of the genus Streptococcus, family Streptococcaceae, order Lactobacillales is proposed, Streptococcuscaviae sp. nov. (type strain Cavy grass 6T=TISTR 2371T=DSM 102819T).

Comparative genomic analysis of multidrug-resistant Streptococcus pneumoniae isolates

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Pan F

2018-05-01

Full Text Available Fen Pan,1 Hong Zhang,1 Xiaoyan Dong,2 Weixing Ye,3 Ping He,4 Shulin Zhang,4 Jeff Xianchao Zhu,5 Nanbert Zhong1,2,6 1Department of Clinical Laboratory, Shanghai Children’s Hospital, Shanghai Jiaotong University, Shanghai, China; 2Department of Respiratory, Shanghai Children’s Hospital, Shanghai Jiaotong University, Shanghai, China; 3Shanghai Personal Biotechnology Co., Ltd, Shanghai, China; 4Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai, China; 5Zhejiang Bioruida Biotechnology co. Ltd, Zhejiang, China; 6New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA Introduction: Multidrug resistance in Streptococcus pneumoniae has emerged as a serious problem to public health. A further understanding of the genetic diversity in antibiotic-resistant S. pneumoniae isolates is needed. Methods: We conducted whole-genome resequencing for 25 pneumococcal strains isolated from children with different antimicrobial resistance profiles. Comparative analysis focus on detection of single-nucleotide polymorphisms (SNPs and insertions and deletions (indels was conducted. Moreover, phylogenetic analysis was applied to investigate the genetic relationship among these strains. Results: The genome size of the isolates was ~2.1 Mbp, covering >90% of the total estimated size of the reference genome. The overall G+C% content was ~39.5%, and there were 2,200–2,400 open reading frames. All isolates with different drug resistance profiles harbored many indels (range 131–171 and SNPs (range 16,103–28,128. Genetic diversity analysis showed that the variation of different genes were associated with specific antibiotic resistance. Known antibiotic resistance genes (pbps, murMN, ciaH, rplD, sulA, and dpr were identified, and new genes (regR, argH, trkH, and PTS-EII closely related with antibiotic resistance were found, although these genes were primarily annotated

QUARTER-WISE COMPARATIVE PREVALENCE OF MASTITIS IN BUFFALOES AND CROSSBRED COWS

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A. Z. Khan and G. Muhammad1

2005-01-01

Full Text Available The present study was designed to determine the quarter-wise comparative prevalence of mastitis in buffaloes and crossbred cows. Milk samples collected from 50 dairy buffaloes and 50 crossbred cows were tested for subclinical mastitis by Surf Field Mastitis Test. In addition, all milk samples were processed for isolation and identification of pathogens. In buffaloes, overall prevalence of subclinical mastitis was 27%, clinical mastitis 4% and blind quarters 10%. In crossbred cows, subclinical mastitis was observed in 36%, clinical mastitis in 5.5% and blind quarters in 8% quarters. Prevalence was higher (32% in hindquarters of crossbred cows than those of buffaloes (29%. Among the isolates, Staphylococcus aureus showed the highest (45% frequency, followed by Streptococcus agalactiae (23%, E. coli (18% and Bacillus spp. (14% in buffaloes. In case of crossbred cows, Staphylococcus aureus , Streptococcus agalactiae , E. coli and Bacillus spp. were isolated from 48, 30, 13 and 8% milk samples respectively.

Binding of glycoprotein Srr1 of Streptococcus agalactiae to fibrinogen promotes attachment to brain endothelium and the development of meningitis.

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Ho Seong Seo

Full Text Available The serine-rich repeat glycoprotein Srr1 of Streptococcus agalactiae (GBS is thought to be an important adhesin for the pathogenesis of meningitis. Although expression of Srr1 is associated with increased binding to human brain microvascular endothelial cells (hBMEC, the molecular basis for this interaction is not well defined. We now demonstrate that Srr1 contributes to GBS attachment to hBMEC via the direct interaction of its binding region (BR with human fibrinogen. When assessed by Far Western blotting, Srr1 was the only protein in GBS extracts that bound fibrinogen. Studies using recombinant Srr1-BR and purified fibrinogen in vitro confirmed a direct protein-protein interaction. Srr1-BR binding was localized to amino acids 283-410 of the fibrinogen Aα chain. Structural predictions indicated that the conformation of Srr1-BR is likely to resemble that of SdrG and other related staphylococcal proteins that bind to fibrinogen through a "dock, lock, and latch" mechanism (DLL. Deletion of the predicted latch domain of Srr1-BR abolished the interaction of the BR with fibrinogen. In addition, a mutant GBS strain lacking the latch domain exhibited reduced binding to hBMEC, and was significantly attenuated in an in vivo model of meningitis. These results indicate that Srr1 can bind fibrinogen directly likely through a DLL mechanism, which has not been described for other streptococcal adhesins. This interaction was important for the pathogenesis of GBS central nervous system invasion and subsequent disease progression.

Streptococcus penaeicida sp. nov., isolated from a diseased farmed Pacific white shrimp (Penaeus vannamei).

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Morales-Covarrubias, Maria Soledad; Del Carmen Bolan-Mejía, María; Vela Alonso, Ana Isabel; Fernandez-Garayzabal, Jose F; Gomez-Gil, Bruno

2018-05-01

Strain CAIM 1838 T , isolated from the hepatopancreas of a cultured diseased Pacific white shrimp (Penaeus vannamei), was subjected to characterization by a polyphasic taxonomic approach. On the basis of 16S rRNA gene sequence analysis, strain CAIM 1838 T was most closely related to Streptococcus bovimastitidis 99.3 % and to other species of the Pyogenes clade of Streptococcus with lower similarity values. Average nucleotide identity values and the genome-to-genome distance of strain CAIM 1838 T , as compared with the type strains, confirmed the separate species status with closely related species of the genus Streptococcus and were all below the thresholds to delimit a species, 93.1 and 49.4 %, respectively. The DNA G+C content was 38.1 mol%. Differential phylogenetic distinctiveness together with phenotypic properties obtained in this study revealed that strain CAIM 1838 T could be differentiated from the closely related species. Based on these results it is proposed that strain CAIM 1838 T represents a novel species in the genus Streptococcus, for which the name Streptococcus penaeicida sp. nov is proposed (type strain, CAIM 1838 T =CECT 8596 T ,=DSM26545 T ), is proposed.

Competence without a competence pheromone in a natural isolate of Streptococcus infantis

DEFF Research Database (Denmark)

Ween, O; Teigen, S; Gaustad, P

2002-01-01

C and a two-component regulatory system encoded by comDE. Here we report that a natural isolate of a mitis group streptococcus (Atu-4) is competent for genetic transformation even though it has lost the gene encoding the competence pheromone. In contrast to other strains, induction of competence in Atu-4...

Frequency and expression of mutacin biosynthesis genes in isolates of Streptococcus mutans with different mutacin-producing phenotypes.

Science.gov (United States)

Kamiya, Regianne Umeko; Höfling, José Francisco; Gonçalves, Reginaldo Bruno

2008-05-01

The aim of this study was to analyse the frequency and expression of biosynthesis genes in 47 Streptococcus mutans isolates with different mutacin-producing phenotypes. Detection of the frequency and expression of genes encoding mutacin types I, II, III and IV were carried out by PCR and semi-quantitative RT-PCR, respectively, using primers specific for each type of biosynthesis gene. In addition, a further eight genes encoding putative bacteriocins, designated bsm 283, bsm 299, bsm 423, bsm 1889c, bsm 1892c, bsm 1896, bsm 1906c and bsm 1914, were also screened. There was a high phenotypic diversity; some Streptococcus mutans isolates presented broad antimicrobial spectra against other Streptococcus mutans clinical isolates, including bacteria resistant to common antibiotics, as well as Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Streptococcus pyogenes. The expression frequency of the bsm gene was higher than that of the previously characterized mutacins (I-IV). There was no positive correlation between the number of indicator strains inhibited (antimicrobial spectra) and the number of biosynthesis genes expressed (Spearman correlation test, r=-0.03, P>0.05). In conclusion, the high diversity of mutacin-producing phenotypes, associated with high frequency of expression of the biosynthesis genes screened, reveals a broad repertoire of genetic determinants encoding antimicrobial peptides that can act in different combinations.

Evaluation of procedures for typing of group B Streptococcus: a retrospective study

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Hans-Christian Slotved

2017-03-01

Full Text Available Background This study evaluates two procedures for typing of Streptococcus agalactiae (group B streptococci; GBS isolates, using retrospective typing data from the period 2010 to 2014 with a commercial latex agglutination test (latex test and the Lancefield precipitation test (LP test. Furthermore, the genotype distribution of phenotypically non-typable (NT GBS isolates is presented. We also raise the awareness, that the difference in typing results obtained by phenotypical methods and genotype based methods may have implications on vaccine surveillance in case a GBS vaccine is introduced. Methods A total of 616 clinical GBS isolates from 2010 to 2014 were tested with both a latex test and the LP test. Among these, 66 isolates were genotyped by PCR, including 41 isolates that were phenotypically NT. Results The latex test provided a serotype for 83.8% of the isolates (95% CI [80.7–86.6] compared to 87.5% (95% CI [84.6–90.0] obtained by the LP method. The two assays provided identical capsular identification for all sero-typeable isolates (excluding NT isolates. The PCR assay provided a genotype designation to the 41 isolates defined as phenotypically NT isolates. Discussion We found that the latex test showed a slightly lower identification percentage than the LP test. Our recommendation is to use the latex agglutination as the routine primary assay for GBS surveillance, and then use the more labour intensive precipitation test on the NT isolates to increase the serotyping rate. A genotype could be assigned to all the phenotypically NT isolates, however, as a consequence genotyping will overestimate the coverage from possible future capsular polysaccharide based GBS vaccines.

Mycoplasma agalactiae Induces Cytopathic Effects in Infected Cells Cultured In Vitro.

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Shrilakshmi Hegde

Full Text Available Mycoplasma agalactiae is the etiological agent of the contagious agalactia syndrome in sheep and goats and causes significant economic losses worldwide. Yet the mechanism of pathogenesis is largely unknown. Even whole-genome sequence analysis of its pathogenic type strain did not lead to any conclusions regarding its virulence or pathogenicity factors. Although inflammation and tissue destruction at the local site of M. agalactiae infection are largely considered as effects of the host immune response, the direct effect of the agent on host cells is not completely understood. The aim of this study was to investigate the effect of M. agalactiae infection on the quality and viability of host cells in vitro. Changes in cell morphology including cell elongation, cytoplasm shrinkage and membrane blebbing were observed in infected HeLa cells. Chromatin condensation and increased caspase-3 cleavage in infected HeLa cells 48 h after infection suggests an apoptosis-like phenomenon in M. agalactiae-infected cells. In compliance with these results, decreased viability and cell lysis of M. agalactiae-infected HeLa cells was also observed. Measurement of the amount of LDH released after M. agalactiae infection revealed a time- and dose-dependent increase in HeLa cell lysis. A significant decrease in LDH released after gentamicin treatment of infected cells confirmed the major role of cytadherent M. agalactiae in inducing host cell lysis. This is the first study illustrating M. agalactiae's induction of cytopathic effects in infected HeLa cells. Further detailed investigation of infected host tissue for apoptotic markers might demonstrate the association between M. agalactiae-induced host cell lysis and the tissue destruction observed during M. agalactiae natural infection.

Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012.

Science.gov (United States)

Moore, Catrin E; Giess, Adam; Soeng, Sona; Sar, Poda; Kumar, Varun; Nhoung, Pheakdey; Bousfield, Rachel; Turner, Paul; Stoesser, Nicole; Day, Nicholas P J; Parry, Christopher M

2016-01-01

The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation. All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing. There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9-6.2). The case fatality was 15.6% (95% CI 8-23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing. This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012.

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Catrin E Moore

Full Text Available The 13-valent pneumococcal vaccine (PCV13 was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD. Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation.All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing.There were 90 Cambodian children hospitalized with IPD with a median (IQR age of 2.3 years (0.9-6.2. The case fatality was 15.6% (95% CI 8-23. Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%, 23F (8/50; 16%, 14 (6/50; 12%, 5 (5/50; 10% and 19A (3/50; 6%. Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing.This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

BACTERIOLOGY OF MASTITIS IN BUFFALOES IN TEHSIL SAMUNDRI OF DISTRICT FAISALABAD, PAKISTAN

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L. ALI, G. MUHAMMAD, M. ARSHAD1, M. SAQIB AND I. J. HASSAN2

2008-01-01

Full Text Available Two hundred fore-milk samples collected from 200 mastitis quarters of buffaloes (clinically mastitis quarters n = 17, sub-clinically mastitis quarters n = 183 were subjected to microbiological examination. The diagnosis of sub-clinical mastitis was based on the results of Surf Field Mastitis Test (SFMT. A total of 214 isolates of 13 different microbial species were recovered. Staphylococcus aureus was the most frequently recovered bacterial species accounting for 49.53% of all the isolates, followed by Streptococcus agalactiae (23.83%, Staphylococcus hyicus (8.88%, Staphylococcus epidermidis (6.54%, Bacillus spp. (3.74%, Staphylococcus hominis (1.40%, Escherichia coli (1.40%, Staphylococcus xylosus (0.93%, Streptococcus dysgalactiae (0.93% and Corynebacterial spp. (0.93%. Yeast and prototheca each accounted for 0.47 percent of isolates. Two (0.93% isolates were identified as coagulase negative staphylococci species. In view of preponderance of the contagious pathogens (S. aureus, Str. agalactiae, it is recommended that mastitis control in the area of study should be based on contagious mastitis control practice.

First isolation of Mycoplasma capricolum subsp. capricolum, one of the causal agents of caprine contagious agalactia, on the island of Lanzarote (Spain).

Science.gov (United States)

De la Fe, C; Gutiérrez, A; Poveda, J B; Assunção, P; Ramírez, A S; Fabelo, F

2007-03-01

During an unusually long period of bad weather, several outbreaks of caprine contagious agalactia (CCA) were reported in a number of flocks on the island of Lanzarote (Canary Islands, Spain). Clinical and subclinical mastitis in lactating goats and some cases of arthritis and pneumonia in kids were observed in the affected flocks. Mycoplasma capricolum subsp. capricolum was isolated as the main causal agent of the outbreaks, associated with M. mycoides subsp. mycoides "large colony type" (Mmm LC) in two flocks. This is the first report of an isolation of M. capricolum subsp. capricolum on the island of Lanzarote. The finding is of epidemiological importance and could complicate plans to control the disease. The significance of this mycoplasma species in association with CCA must now be studied in detail.

Short communication: Conservation of Streptococcus uberis adhesion molecule and the sua gene in strains of Streptococcus uberis isolated from geographically diverse areas.

Science.gov (United States)

Yuan, Ying; Dego, Oudessa Kerro; Chen, Xueyan; Abadin, Eurife; Chan, Shangfeng; Jory, Lauren; Kovacevic, Steven; Almeida, Raul A; Oliver, Stephen P

2014-12-01

The objective was to identify and sequence the sua gene (GenBank no. DQ232760; http://www.ncbi.nlm.nih.gov/genbank/) and detect Streptococcus uberis adhesion molecule (SUAM) expression by Western blot using serum from naturally S. uberis-infected cows in strains of S. uberis isolated in milk from cows with mastitis from geographically diverse areas of the world. All strains evaluated yielded a 4.4-kb sua-containing PCR fragment that was subsequently sequenced. Deduced SUAM AA sequences from those S. uberis strains evaluated shared >97% identity. The pepSUAM sequence located at the N terminus of SUAM was >99% identical among strains of S. uberis. Streptococcus uberis adhesion molecule expression was detected in all strains of S. uberis tested. These results suggest that sua is ubiquitous among strains of S. uberis isolated from diverse geographic locations and that SUAM is immunogenic. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Complete Atrioventricular Block Complicating Mitral Infective Endocarditis Caused by Streptococcus Agalactiae

OpenAIRE

Arai, Masaru; Nagashima, Koichi; Kato, Mahoto; Akutsu, Naotaka; Hayase, Misa; Ogura, Kanako; Iwasawa, Yukino; Aizawa, Yoshihiro; Saito, Yuki; Okumura, Yasuo; Nishimaki, Haruna; Masuda, Shinobu; Hirayama, Atsushi

2016-01-01

Patient: Male, 74 Final Diagnosis: Infective endocarditis Symptoms: Apetite loss ? fever Medication: ? Clinical Procedure: Transesophageal echocardiography Specialty: Cardiology Objective: Rare co-existance of disease or pathology Background: Infective endocarditis (IE) involving the mitral valve can but rarely lead to complete atrioventricular block (CAVB). Case Report: A 74-year-old man with a history of infective endocarditis caused by Streptococcus gordonii (S. gordonii) presented to our ...

Characterization of the duodenase-1 gene and its associations with resistance to Streptococuus agalactiae in hybrid tilapia (Oreochromis spp.).

Science.gov (United States)

Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

2015-08-01

Tilapia is a group of cultured teleost fishes whose production is threatened by some diseases. Identification of DNA markers associated with disease resistance in candidate genes may facilitate to accelerate the selection of disease resistance. The gene encoding a duodenase, which can trigger immune response, has not been studied in fish. We characterized the cDNA of duodenase-1 gene of hybrid tilapia. Its ORF is 759 bp, encoding a serine protease of 252 amino acids. This gene consisted of five exons and four introns. Its expression was detected in all 10 tissues examined, and it was highly expressed in the intestine and kidney. After a challenge with the bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the intestine, liver and spleen. We identified seven SNPs in the gene and found that four of them were significantly associated with the resistance to S. agalactiae (P tilapia. The SNP markers in the duodenase-1 gene associated with resistance to the bacterial pathogen, may facilitate the selection of tilapia resistant to the bacterial disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Antibiotic resistance analysis of Streptococcus pneumoniae isolates from the hospitalized children in Shanxi Children's Hospital from 2012 to 2014].

Science.gov (United States)

Ge, L L; Han, Z Y; Liu, A H; Zhu, L; Meng, J H

2017-02-02

Objective: To investigate the antibiotic resistance status of Streptococcus pneumoniae isolates from hospitalized children in Shanxi Children's Hospital. Method: E-test and Kirby-Bauer methods were applied to determine drug sensitivity of the isolates collected from the body fluid specimens of hospitalized children in Shanxi Children's Hospital from January 2012 to December 2014. The antimicrobial sensitivity and minimum inhibitory concentration (MIC) of Streptococcus pneumoniae to the conventional antibiotics were analyzed, in order to compare the annual trends of non-invasive isolates, while the differentiation of sensitivity from specimens. The comparison of rates was performed by Chi-squared test and Fisher's exact test. Result: A total of 671 isolates of streptococcus pneumoniae were obtained, which could be divided as non-invasive isolates(607), invasive isolates from non-cerebrospinal fluid(non-CSF)(40) and invasive isolates from cerebrospinal fluid(CSF)(24). The antimicrobial sensitivity(isolates(%)) of the 671 isolates were respectively vancomycin 671(100.0%), linezolid 671(100.0%), levofloxacin 665(99.1%), penicillin 595(88.7%), ceftriaxone 516(76.9%), cefotaxime 512(76.3%), sulfamethoxazole-trimethoprin(SMZ-TMP) 103(15.4%), clindamycin 28(4.2%), tetracycline 26(3.9%), erythromycin 12(1.8%). From 2012 to 2014, the susceptibility rates of non-invasive isolates to penicillin every year were 95.0%(96/101), 97.3%(110/113), 87.3%(343/393), respectively, and there was significant difference among the three years(χ(2)=13.266, P penicillin were 0.064, 2.000, 6.000 in 2012, which grew up to 1.000, 3.000, 16.000 in 2014. There was no significant difference in the susceptibility rate of non-invasive isolates to ceftriaxone and cefotaxime during these three years, (χ(2)=1.172, 1.198, both P >0.05). On the other hand, the values of MIC(50, )MIC(90) and the maximum value of MIC(mg/L) of ceftriaxone and cefotaxime both increased from 0.500, 2.000, 8.000 in 2012 to 0

Structure of a conjugative element in Streptococcus pneumoniae

Energy Technology Data Exchange (ETDEWEB)

Vijayakumar, M.N.; Priebe, S.D.; Guild, W.R.

1986-06-01

The authors have cloned and mapped a 69-kilobase (kb) region of the chromosome of Streptococcus pneumoniae DP1322, which carries the conjugative Omega(cat-tet) insertion from S. pneumoniae BM6001. This element proved to be 65.5 kb in size. Location of the junctions was facilitated by cloning a preferred target region from the wild-type strain Rx1 recipient genome. This target site was preferred by both the BM6001 element and the cat-erm-tet element from Streptococcus agalactiae B109. Within the BM6001 element cat and tet were separated by 30 kb, and cat was flanked by two copies of a sequence that was also present in the recipient strain Rx1 DNA. Another sequence at least 2.4 kb in size was found inside the BM6001 element and at two places in the Rx1 genome. Its role is unknown. The ends of the BM6001 element appear to be the same as those of the B109 element, both as seen after transfer to S. pneumoniae and as mapped by others in pDP5 after transposition in Streptococcus faecalis. No homology is seen between the ends of the BM6001 element and no evidence found suggesting that it ever circularizes.

Prevalence and Characteristics of Streptococcus canis Strains Isolated from Dogs and Cats

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P. Lysková

2007-01-01

Full Text Available To determine the prevalence of Streptococcus canis in dogs and cats, a total of 926 swabs were examined bacteriologically in the period from 2003 to 2005. Eighty-six isolates obtained from various anatomical locations were further characterized for their phenotypic properties. The most frequently isolated biotype produced phosphatase, leucine amidopeptidase, arginine dihydrolase, alpha-D- and beta-D-galactosidase and fermented lactose and ribose. Additional identification by species-specific amplification of the 16S-23S rRNA intergenic spacer region was consistent with S. canis. All isolates were susceptible to penicillin G and ampicillin. The least effective antimicrobial agent was found to be tetracycline (only 33.8% of susceptible strains.

Streptococcus lutetiensis Bacteremia. First Clindamycin Resistant Isolate Carrying lnuB Gene

OpenAIRE

Almuzara, Marisa; Bonofiglio, Laura; Cittadini, Roberto Arnaldo; Vera Ocampo, C.; Montilla, A.; del Castillo, M.; Ramirez, Maria Soledad; Mollerach, Marta Eugenia; Vay, C.

2015-01-01

First Case of Streptococcus lutetiensis Bacteremia Involving a Clindamycin-Resistant Isolate Carrying the lnuB Gene Fil: Almuzara, Marisa. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina; Fil: Bonofiglio, Laura. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; Argentina; Fil: Cittadini, Roberto Arnaldo. Instituto Nacional de Tecnologia Agropecuaria;...

Molecular and antimicrobial susceptibility profiling of atypical Streptococcus species from porcine clinical specimens.

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Moreno, Luisa Z; Matajira, Carlos E C; Gomes, Vasco T M; Silva, Ana Paula S; Mesquita, Renan E; Christ, Ana Paula G; Sato, Maria Inês Z; Moreno, Andrea M

2016-10-01

The Streptococcus species present broad phenotypic variation, making identification difficult using only traditional microbiological methods. Even though Streptococcus suis is the most important species for the worldwide swine industry, other Streptococcus species appear to be able to cause disease in swine and could represent a higher underestimated risk for porcine health. The aim of this study was to identify Streptococcus-like isolates by MALDI-TOF MS and 16S rRNA sequencing and further molecular and antibiotic susceptibility characterization of the atypical Streptococcus species capable of causing disease in swine. Fifty presumptive Streptococcus isolates from diseased pigs isolated from different Brazilian States between 2002 and 2014 were evaluated. Among the studied isolates, 26% were identified as Streptococcus hyovaginalis, 24% as Streptococcus plurianimalium, 12% as Streptococcus alactolyticus, 10% as Streptococcus hyointestinalis, and the remaining isolates belonged to Streptococcus henryi (6%), Streptococcus thoraltensis (6%), Streptococcus gallolyticus (6%), Streptococcus gallinaceus (4%), Streptococcus sanguinis (4%), and Streptococcus mitis (2%). The Streptococcus isolates were successfully identified by spectral cluster analysis and 16S rRNA sequencing with 96% of concordance between the techniques. The SE-AFLP analysis also supported Streptococcus species distinction and enabled further observation of higher genetic heterogeneity intra-species. The identified Streptococcus species presented variable MIC values to β-lactams, enrofloxacin and florfenicol, and high resistance rates to tetracyclines and macrolides, which appear to be directly related to the industry's antimicrobial usage and resistance selection. Copyright © 2016 Elsevier B.V. All rights reserved.

An outbreak of acute bovine mastitis caused by Klebsiella pneumoniae in a dairy herd

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Silva N.

2001-01-01

Full Text Available An outbreak of coliform mastitis is described in a dairy herd from the State of Rio de Janeiro, Brazil. During a four-month period 14 fatal cases of Klebsiella pneumoniae-related mastitis were observed in a herd of 104 lactating cows. The symptoms included peracute enterotoxemia in which the cows died 6 to 12 h after the detection of mastitis by CMT. Staphylococcus aureus and Streptococcus agalactiae Streptococcus agalactiae were also isolated although could not be associated with cases of acute fatal mastitis. Milking practices were also evaluated. The milking machine was being used correctly and adequate precautions for hygiene and pre-milking and post-milking teat dipping were used. The organism was sensitive to gentamicin. Therapy for acute toxic mastitis required early action for the treatment of infections, involving corticosteroids and fluid therapy. The use of a Klebsiella vaccine produced from the microorganisms isolated from the herd, associated with hygiene measures, resulted in the control of the outbreak.

Estimation of test characteristics of real-time PCR and bacterial culture for diagnosis of subclinical intramammary infections with Streptococcus agalactiae in Danish dairy cattle in 2012 using latent class analysis

DEFF Research Database (Denmark)

Mahmmod, Yasser; Toft, Nils; Katholm, Jørgen

2013-01-01

threshold (Ct) values against bacterial culture (BC) for diagnosis of S. agalactiae IMI using latent class analysis to avoid the assumption of a perfect reference test. A total of 614 dairy cows were randomly selected from 6 herds with bulk tank PCR Ct value ≤ 39 for S. agalactiae and S. aureus. At milk...... cut-offs, indicating under estimation of S. agalactiae IMI in the examined dairy cows. In conclusion, Se of PCR is always higher than Se of BC at all tested cut-offs. The lower cut-off, the more comparable becomes Se of PCR and Se of BC. The changes in Se in both PCR and BC at different Ct-value cut...... definition of infection may reflect a more general condition of cows being positive for S. agalactiae. Our findings indicate that PCR Ct-value cut-offs should be chosen according to the underlying latent infection definition of interest. Latent class analysis proposes a useful alternative to classic test...

Genomic analysis reveals the molecular basis for capsule loss in the group B Streptococcus population.

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Roberto Rosini

Full Text Available The human and bovine bacterial pathogen Streptococcus agalactiae (Group B Streptococcus, GBS expresses a thick polysaccharide capsule that constitutes a major virulence factor and vaccine target. GBS can be classified into ten distinct serotypes differing in the chemical composition of their capsular polysaccharide. However, non-typeable strains that do not react with anti-capsular sera are frequently isolated from colonized and infected humans and cattle. To gain a comprehensive insight into the molecular basis for the loss of capsule expression in GBS, a collection of well-characterized non-typeable strains was investigated by genome sequencing. Genome based phylogenetic analysis extended to a wide population of sequenced strains confirmed the recently observed high clonality among GBS lineages mainly containing human strains, and revealed a much higher degree of diversity in the bovine population. Remarkably, non-typeable strains were equally distributed in all lineages. A number of distinct mutations in the cps operon were identified that were apparently responsible for inactivation of capsule synthesis. The most frequent genetic alterations were point mutations leading to stop codons in the cps genes, and the main target was found to be cpsE encoding the portal glycosyl transferase of capsule biosynthesis. Complementation of strains carrying missense mutations in cpsE with a wild-type gene restored capsule expression allowing the identification of amino acid residues essential for enzyme activity.

Virulence Gene Pool Detected in Bovine Group C Streptococcus dysgalactiae subsp. dysgalactiae Isolates by Use of a Group A S. pyogenes Virulence Microarray ▿

Science.gov (United States)

Rato, Márcia G.; Nerlich, Andreas; Bergmann, René; Bexiga, Ricardo; Nunes, Sandro F.; Vilela, Cristina L.; Santos-Sanches, Ilda; Chhatwal, Gursharan S.

2011-01-01

A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi, and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans. PMID:21525223

Spatiotemporal patterns, annual baseline and movement-related incidence of Streptococcus agalactiae infection in Danish dairy herds: 2000–2009

DEFF Research Database (Denmark)

Mweu, Marshal M.; Nielsen, Søren S.; Hisham Beshara Halasa, Tariq

2014-01-01

-herd sources of new herd infections coupled with the spatiotemporal distribution of the infection, may aid in effective targeting of control efforts. Thus, the objectives of this study were: (1) to describe the spatiotemporal patterns of infection with S. agalactiae in the population of Danish dairy herds from...

Immunogenic properties of Streptococcus agalactiae FbsA fragments.

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Salvatore Papasergi

Full Text Available Several species of Gram-positive bacteria can avidly bind soluble and surface-associated fibrinogen (Fng, a property that is considered important in the pathogenesis of human infections. To gain insights into the mechanism by which group B Streptococcus (GBS, a frequent neonatal pathogen, interacts with Fng, we have screened two phage displayed genomic GBS libraries. All of the Fng-binding phage clones contained inserts encoding fragments of FbsA, a protein displaying multiple repeats. Since the functional role of this protein is only partially understood, representative fragments were recombinantly expressed and analyzed for Fng binding affinity and ability to induce immune protection against GBS infection. Maternal immunization with 6pGST, a fragment containing five repeats, significantly protected mouse pups against lethal GBS challenge and these protective effects could be recapitulated by administration of anti-6pGST serum from adult animals. Notably, a monoclonal antibody that was capable of neutralizing Fng binding by 6pGST, but not a non-neutralizing antibody, could significantly protect pups against lethal GBS challenge. These data suggest that FbsA-Fng interaction promotes GBS pathogenesis and that blocking such interaction is a viable strategy to prevent or treat GBS infections.

Evolution and Diversity of the Antimicrobial Resistance Associated Mobilome in Streptococcus suis: A Probable Mobile Genetic Elements Reservoir for Other Streptococci.

Science.gov (United States)

Huang, Jinhu; Ma, Jiale; Shang, Kexin; Hu, Xiao; Liang, Yuan; Li, Daiwei; Wu, Zuowei; Dai, Lei; Chen, Li; Wang, Liping

2016-01-01

Streptococcus suis is a previously neglected, newly emerging multidrug-resistant zoonotic pathogen. Mobile genetic elements (MGEs) play a key role in intra- and interspecies horizontal transfer of antimicrobial resistance (AMR) determinants. Although, previous studies showed the presence of several MGEs, a comprehensive analysis of AMR-associated mobilome as well as their interaction and evolution has not been performed. In this study, we presented the AMR-associated mobilome and their insertion hotspots in S. suis . Integrative conjugative elements (ICEs), prophages and tandem MGEs were located at different insertion sites, while 86% of the AMR-associated MGEs were inserted at rplL and rum loci. Comprehensive analysis of insertions at rplL and rum loci among four pathogenic Streptococcus species ( Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes , and S. suis ) revealed the existence of different groups of MGEs, including Tn5252, ICE Sp 1108, and TnGBS2 groups ICEs, Φm46.1 group prophage, ICE_ICE and ICE_prophage tandem MGEs. Comparative ICE genomics of ICE Sa 2603 family revealed that module exchange and acquisition/deletion were the main mechanisms in MGEs' expansion and evolution. Furthermore, the observation of tandem MGEs reflected a novel mechanism for MGE diversity. Moreover, an in vitro competition assay showed no visible fitness cost was observed between different MGE-carrying isolates and a conjugation assay revealed the transferability of ICE Sa 2603 family of ICEs. Our statistics further indicated that the prevalence and diversity of MGEs in S. suis is much greater than in other three species which prompted our hypothesis that S. suis is probably a MGEs reservoir for other streptococci. In conclusion, our results showed that acquisition of MGEs confers S. suis not only its capability as a multidrug resistance pathogen, but also represents a paradigm to study the modular evolution and matryoshkas of MGEs.

Evolution and diversity of the antimicrobial resistance associated mobilome in Streptococcus suis: a probable mobile genetic elements reservoir for other streptococci

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Jinhu Huang

2016-10-01

Full Text Available Streptococcus suis is a previously neglected, newly emerging multidrug-resistant zoonotic pathogen. Mobile genetic elements (MGEs play a key role in intra- and interspecies horizontal transfer of antimicrobial resistance (AMR determinants. Although previous studies showed the presence of several MGEs, a comprehensive analysis of AMR-associated mobilome as well as their interaction and evolution has not been performed. In this study, we presented the AMR-associated mobilome and their insertion hotspots in S. suis. Integrative conjugative elements (ICEs, prophages and tandem MGEs were located at different insertion sites, while 86% of the AMR-associated MGEs were inserted at rplL and rum loci. Comprehensive analysis of insertions at rplL and rum loci among four pathogenic Streptococcus species (Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, and S. suis revealed the existence of different groups of MGEs, including Tn5252, ICESp1108, and TnGBS2 groups ICEs, Φm46.1 group prophage, ICE_ICE and ICE_prophage tandem MGEs. Comparative ICE genomics of ICESa2603 family revealed that module exchange and acquisition/deletion were the main mechanisms in MGEs’ expansion and evolution. Furthermore, the observation of tandem MGEs reflected a novel mechanism for MGE diversity. Moreover, an in vitro competition assay showed no visible fitness cost was observed between different MGE-carrying isolates and a conjugation assay revealed the transferability of ICESa2603 family of ICEs. Our statistics further indicated that the prevalence and diversity of MGEs in S. suis is much greater than in other three species which prompted our hypothesis that S. suis is probably a MGEs reservoir for other streptococci. In conclusion, our results showed that acquisition of MGEs confers S. suis not only its capability as a multidrug resistance pathogen, but also represents a paradigm to study the modular evolution and matryoshkas of MGEs.

Influencia de la composici??n del medio de cultivo sobre la producci??n de pigmento por Streptococcus agalactiae

OpenAIRE

Carazo Carazo, Concepci??n

1995-01-01

Se ha estudiado la influencia de la composici??n del medio de cultivo sobre la producci??n de pigmento por s. agalactiae partiendo de un medio de cultivo dise??ado para tal finalidad (new granada medium), eliminando uno a uno los componentes incluidos en su formulaci??n original. Almid??n, proteosa peptona (difco), suero, fosfatos y metrotexato influyen de forma importante en la formaci??n y/o visualizaci??n del pigmento producido por este microorganismo. Se ha determinado que la fracci??n de...

Streptococcus oligofermentans inhibits Streptococcus mutans in biofilms at both neutral pH and cariogenic conditions

NARCIS (Netherlands)

Bao, X.; de Soet, J.J.; Tong, H.; Gao, X.; He, L.; van Loveren, C.; Deng, D.M.

2015-01-01

Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide

Cariogenic properties of Streptococcus mutans clinical isolates with sortase defects.

Science.gov (United States)

Lapirattanakul, Jinthana; Takashima, Yukiko; Tantivitayakul, Pornpen; Maudcheingka, Thaniya; Leelataweewud, Pattarawadee; Nakano, Kazuhiko; Matsumoto-Nakano, Michiyo

2017-09-01

In Streptococcus mutans, a Gram-positive pathogen of dental caries, several surface proteins are anchored by the activity of sortase enzyme. Although various reports have shown that constructed S. mutans mutants deficient of sortase as well as laboratory reference strains with a sortase gene mutation have low cariogenic potential, no known studies have investigated clinical isolates with sortase defects. Here, we examined the cariogenic properties of S. mutans clinical isolates with sortase defects as well as caries status in humans harboring such defective isolates. Sortase-defective clinical isolates were evaluated for biofilm formation, sucrose-dependent adhesion, stress-induced dextran-dependent aggregation, acid production, and acid tolerance. Additionally, caries indices of subjects possessing such defective isolates were determined. Our in vitro results indicated that biofilm with a lower quantity was formed by sortase-defective as compared to non-defective isolates. Moreover, impairments of sucrose-dependent adhesion and stress-induced dextran-dependent aggregation were found among the isolates with defects, whereas no alterations were seen in regard to acid production or tolerance. Furthermore, glucan-binding protein C, a surface protein anchored by sortase activity, was predominantly detected in culture supernatants of all sortase-defective S. mutans isolates. Although the sortase-defective isolates showed lower cariogenic potential because of a reduction in some cariogenic properties, deft/DMFT indices revealed that all subjects harboring those isolates had caries experience. Our findings suggest the impairment of cariogenic properties in S. mutans clinical isolates with sortase defects, though the detection of these defective isolates seemed not to imply low caries risk in the subjects harboring them. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of real-time PCR for detection and quantitation of Streptococcus parauberis.

Science.gov (United States)

Nguyen, T L; Lim, Y J; Kim, D-H; Austin, B

2016-01-01

Streptococcus parauberis is an increasing threat to aquaculture of olive flounder, Paralichthys olivaceus Temminck & Schlegel, in South Korea. We developed a real-time polymerase chain reaction (PCR) method using the TaqMan probe assay to detect and quantify S. parauberis by targeting the gyrB gene sequences, which are effective for molecular analysis of the genus Streptococcus. Our real-time PCR assay is capable of detecting 10 fg of genomic DNA per reaction. The intra- and interassay coefficient of variation (CV) values ranged from 0.42-1.95%, demonstrating that the assay has good reproducibility. There was not any cross-reactivity to Streptococcus iniae or to other streptococcal/lactococcal fish pathogens, such as S. agalactiae and Lactococcus garvieae, indicating that the assay is highly specific to S. parauberis. The results of the real-time PCR assay corresponded well to those of conventional culture assays for S. parauberis from inoculated tissue homogenates (r = 0.957; P < 0.05). Hence, this sensitive and specific real-time PCR is a valuable tool for diagnostic quantitation of S. parauberis in clinical samples. © 2014 John Wiley & Sons Ltd.

Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 – 2012

Science.gov (United States)

Giess, Adam; Soeng, Sona; Sar, Poda; Kumar, Varun; Nhoung, Pheakdey; Bousfield, Rachel; Turner, Paul; Stoesser, Nicole; Day, Nicholas P. J.; Parry, Christopher M.

2016-01-01

Background The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation. Methods All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing. Results There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9–6.2). The case fatality was 15.6% (95% CI 8–23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing. Conclusions This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel

Comparative Genomic Analysis of the ICESa2603 Family ICEs and Spread of erm(B- and tet(O-Carrying Transferable 89K-Subtype ICEs in Swine and Bovine Isolates in China

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Jinhu eHuang

2016-02-01

Full Text Available Integrative and conjugative elements (ICEs of the ICESa2603 family have been isolated from several species of Streptococcus spp.; however, the comparative genomic and evolutionary analyses of these particular ICEs are currently only at their initial stages. By investigating 13 ICEs of the ICESa2603 family and two ICESa2603 family-like ICEs derived from diverse hosts and locations, we have determined that ICEs comprised a backbone of 30 identical syntenic core genes and accessory genes that were restricted to the intergenic sites or the 3'-end of the non-conserved domain of core genes to maintain its function. ICESa2603 family integrase IntICESa2603 specifically recognized a 15-bp att sequence (TTATTTAAGAGTAAC at the 3'-end of rplL, which was highly conserved in genus Streptococcus. Phylogenetic analyses suggest that extensive recombination/insertion and the occurrence of a hybrid/mosaic in the ICESa2603 family were responsible for the significant increase in ICE diversity, thereby broadening its host range. Approximately 42.5% and 38.1% of the tested Streptococcus suis and Streptococcus agalactiae clinical isolates respectively contained ICESa2603 family Type Ⅳ secretion system (T4SS genes, and 80.5% and 62.5% of which also respectively carried intICESa2603, indicating that ICESa2603 family is widely distributed across these bacteria. Sequencing and conjugation transfer of a novel sequence type ST303 clinical S. suis isolate HB1011 demonstrated that the 89K-subtype ICESsuHB1011 retained its transferrable function, thereby conferring tetracycline and macrolide resistance.

Diversity of human small intestinal Streptococcus and Veillonella populations.

Science.gov (United States)

van den Bogert, Bartholomeus; Erkus, Oylum; Boekhorst, Jos; de Goffau, Marcus; Smid, Eddy J; Zoetendal, Erwin G; Kleerebezem, Michiel

2013-08-01

Molecular and cultivation approaches were employed to study the phylogenetic richness and temporal dynamics of Streptococcus and Veillonella populations in the small intestine. Microbial profiling of human small intestinal samples collected from four ileostomy subjects at four time points displayed abundant populations of Streptococcus spp. most affiliated with S. salivarius, S. thermophilus, and S. parasanguinis, as well as Veillonella spp. affiliated with V. atypica, V. parvula, V. dispar, and V. rogosae. Relative abundances varied per subject and time of sampling. Streptococcus and Veillonella isolates were cultured using selective media from ileostoma effluent samples collected at two time points from a single subject. The richness of the Streptococcus and Veillonella isolates was assessed at species and strain level by 16S rRNA gene sequencing and genetic fingerprinting, respectively. A total of 160 Streptococcus and 37 Veillonella isolates were obtained. Genetic fingerprinting differentiated seven Streptococcus lineages from ileostoma effluent, illustrating the strain richness within this ecosystem. The Veillonella isolates were represented by a single phylotype. Our study demonstrated that the small intestinal Streptococcus populations displayed considerable changes over time at the genetic lineage level because only representative strains of a single Streptococcus lineage could be cultivated from ileostoma effluent at both time points. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

NCBI nr-aa BLAST: CBRC-DNOV-01-2682 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DNOV-01-2682 ref|ZP_00785610.1| DNA internalization-related competence protein... ComEC/Rec2 [Streptococcus agalactiae COH1] gb|EAO75666.1| DNA internalization-related competence protein ComEC/Rec2 [Streptococcus agalactiae COH1] ZP_00785610.1 0.42 24% ...

NCBI nr-aa BLAST: CBRC-DNOV-01-1264 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-DNOV-01-1264 ref|ZP_00785610.1| DNA internalization-related competence protein... ComEC/Rec2 [Streptococcus agalactiae COH1] gb|EAO75666.1| DNA internalization-related competence protein ComEC/Rec2 [Streptococcus agalactiae COH1] ZP_00785610.1 0.58 23% ...

Improved method for rapid and accurate isolation and identification of Streptococcus mutans and Streptococcus sobrinus from human plaque samples.

Science.gov (United States)

Villhauer, Alissa L; Lynch, David J; Drake, David R

2017-08-01

Mutans streptococci (MS), specifically Streptococcus mutans (SM) and Streptococcus sobrinus (SS), are bacterial species frequently targeted for investigation due to their role in the etiology of dental caries. Differentiation of S. mutans and S. sobrinus is an essential part of exploring the role of these organisms in disease progression and the impact of the presence of either/both on a subject's caries experience. Of vital importance to the study of these organisms is an identification protocol that allows us to distinguish between the two species in an easy, accurate, and timely manner. While conducting a 5-year birth cohort study in a Northern Plains American Indian tribe, the need for a more rapid procedure for isolating and identifying high volumes of MS was recognized. We report here on the development of an accurate and rapid method for MS identification. Accuracy, ease of use, and material and time requirements for morphological differentiation on selective agar, biochemical tests, and various combinations of PCR primers were compared. The final protocol included preliminary identification based on colony morphology followed by PCR confirmation of species identification using primers targeting regions of the glucosyltransferase (gtf) genes of SM and SS. This method of isolation and identification was found to be highly accurate, more rapid than the previous methodology used, and easily learned. It resulted in more efficient use of both time and material resources. Copyright © 2017 Elsevier B.V. All rights reserved.

The cell envelope subtilisin-like proteinase is a virulence determinant for Streptococcus suis

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Gottschalk Marcelo

2010-02-01

Full Text Available Abstract Background Streptococcus suis is a major swine pathogen and zoonotic agent that mainly causes septicemia, meningitis, and endocarditis. It has recently been suggested that proteinases produced by S. suis (serotype 2 are potential virulence determinants. In the present study, we screened a S. suis mutant library created by the insertion of Tn917 transposon in order to isolate a mutant deficient in a cell surface proteinase. We characterized the gene and assessed the proteinase for its potential as a virulence factor. Results Two mutants (G6G and M3G possessing a single Tn917 insertion were isolated. The affected gene coded for a protein (SSU0757 that shared a high degree of identity with Streptococccus thermophilus PrtS (95.9% and, to a lesser extent, with Streptococcus agalactiae CspA (49.5%, which are cell surface serine proteinases. The SSU0757 protein had a calculated molecular mass of 169.6 kDa and contained the catalytic triad characteristic of subtilisin family proteinases: motif I (Asp200, motif II (His239, and motif III (Ser568. SSU0757 also had the Gram-positive cell wall anchoring motif (Leu-Pro-X-Thr-Gly at the carboxy-terminus, which was followed by a hydrophobic domain. All the S. suis isolates tested, which belonged to different serotypes, possessed the gene encoding the SSU0757 protein. The two mutants devoid of subtilisin-like proteinase activity had longer generation times and were more susceptible to killing by whole blood than the wild-type parent strain P1/7. The virulence of the G6G and M3G mutants was compared to the wild-type strain in the CD1 mouse model. Significant differences in mortality rates were noted between the P1/7 group and the M3G and G6G groups (p Conclusion In summary, we identified a gene coding for a cell surface subtilisin-like serine proteinase that is widely distributed in S. suis. Evidences were brought for the involvement of this proteinase in S. suis virulence.

Characterization of Streptococcus pneumoniae isolates from Austrian companion animals and horses.

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Ginders, Maximilian; Leschnik, Michael; Künzel, Frank; Kampner, Doris; Mikula, Claudia; Steindl, Georg; Eichhorn, Inga; Feßler, Andrea T; Schwarz, Stefan; Spergser, Joachim; Loncaric, Igor

2017-11-14

The aim of the present study was to investigate the genetic relatedness and the antimicrobial resistance profiles of a collection of Austrian Streptococcus pneumoniae isolates from companion animals and horses. A total of 12 non-repetitive isolates presumptively identified as S. pneumoniae were obtained during routinely diagnostic activities between March 2009 and January 2017. Isolates were confirmed as S. pneumoniae by bile solubility and optochin susceptibility testing, matrix-assisted laser desorption-ionization-time of flight (MALDI-TOF) mass spectrometry and sequence analysis of a part recA and the 16S rRNA genes. Isolates were further characterized by pneumolysin polymerase chain reaction (PCR) and genotyped by multilocus sequence typing (MLST). Antimicrobial susceptibility testing was performed and resistance genes were detected by specific PCR assays. All isolates were serotyped. Four sequence types (ST) (ST36, ST3546, ST6934 and ST6937) and four serotypes (3, 19A, 19F and 23F) were detected. Two isolates from twelve displayed a multidrug-resistance pheno- and genotype. This study represents the first comprehensive investigation on characteristics of S. pneumoniae isolates recovered from Austrian companion animals and horses. The obtained results indicate that common human sero- (23F) and sequence type (ST36) implicated in causing invasive pneumococcal disease (IPD) may circulate in dogs. Isolates obtained from other examined animals seem to be host-adapted.

Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen.

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Ba-Saddik, I A; Munibari, A A; Alhilali, A M; Ismail, S M; Murshed, F M; Coulter, J B S; Cuevas, L E; Hart, C A; Brabin, B J; Parry, C M

2014-04-01

To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD). Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined. Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1). This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains. © 2014 John Wiley & Sons Ltd.

Rapid identification of pathogenic streptococci isolated from moribund red tilapia (Oreochromis spp.).

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Abdelsalam, Mohamed; Elgendy, Mamdouh Y; Shaalan, Mohamed; Moustafa, Mohamed; Fujino, Masayuki

2017-03-01

Accurate and rapid identification of bacterial pathogens of fish is essential for the effective treatment and speedy control of infections. Massive mortalities in market-sized red tilapia (Oreochromis spp.) were noticed in mariculture concrete ponds in northern Egypt. Histopathological examination revealed marked congestion in the central vein of the liver with the presence of bacterial aggregates inside the lumen and in the vicinity of the central vein. A total of 12 isolates of streptococci were obtained from the moribund fish. This study documented the ability of the MicroSeq 500 16S bacterial sequencing method to accurately identify Streptococcus agalactiae and S. dysgalactiae mixed infections from moribund red tilapia that were difficult to be recognised by the commercial biochemical systems. The continuously decreasing cost of the sequencing technique should encourage its application in routine diagnostic procedures.

Survey of strain distribution and antibiotic resistance pattern of group B streptococci (Streptococcus agalactiae isolated from clinical specimens

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Mousavi, Seyed Masoud

2016-09-01

Full Text Available Aim: The aims of the present study were to determine the antibiotic susceptibility profils with particular emphasis on susceptible or resistant strains to macrolides and lincosamids antibiotics and to determine possible antibiotic resistance mechanisms occurring in group B streptococci (GBS strains using PCR assay and disk diffusion method.Methods: A total of 62 clinical GBS strains were investigated. Antibacterial susceptibility testing was performed using the disk diffusion method and inducible resistance test for clindamycin by standard double disk diffusion or D-zone test for all isolates to differentiate macrolide resistance phenotype (M, constitutive macrolide-lincosamide-streptogramin B phenotype (cMLS and induced macrolide-lincosamide-streptogramin B phenotype (iMLS. In addition, minimum inhibitory concentrations (MIC of penicillin were determined for all isolates. Finally, possible existence of antibiotic resistance genes for erythromycin , and and for clindamycin were examined among isolates using PCR assay.Results: All 62 isolates were susceptible to penicillin, ampicillin, linezolid, cefazoline and vancomycin. However, 93.5% (n=58 of isolates showed an increased MIC to penicillin. The overall rate of erythromycin resistance was 35.5% (n=22. All erythromycin-resistant isolates displayed the M phenotype (100%, n=22. All three erythromycin resistance genes (i.e. , and were found in erythromycin-resistant isolates.Conclusion: It was concluded that prescribing antibiotic without antibacterial susceptibility tests should be prevented because of the high prevalence of erythromycin-resistant GBS strains and the fact that erythromycin-resistant GBS strains has shown an increased MIC to penicillin, as the drug of choice for treating GBS infections.

Increased Age, but Not Parity Predisposes to Higher Bacteriuria Burdens Due to Streptococcus Urinary Tract Infection and Influences Bladder Cytokine Responses, Which Develop Independent of Tissue Bacterial Loads.

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Sullivan, Matthew J; Carey, Alison J; Leclercq, Sophie Y; Tan, Chee K; Ulett, Glen C

2016-01-01

Streptococcus agalactiae causes urinary tract infection (UTI) in pregnant adults, non-pregnant adults, immune-compromised individuals and the elderly. The pathogenesis of S. agalactiae UTI in distinct patient populations is poorly understood. In this study, we used murine models of UTI incorporating young mice, aged and dam mice to show that uropathogenic S. agalactiae causes bacteriuria at significantly higher levels in aged mice compared to young mice and this occurs coincident with equivalent levels of bladder tissue colonisation at 24 h post-infection (p.i.). In addition, aged mice exhibited significantly higher bacteriuria burdens at 48 h compared to young mice, confirming a divergent pattern of bacterial colonization in the urinary tract of aged and young mice. Multiparous mice, in contrast, exhibited significantly lower urinary titres of S. agalactiae compared to age-matched nulliparous mice suggesting that parity enhances the ability of the host to control S. agalactiae bacteriuria. Additionally, we show that both age and parity alter the expression levels of several key regulatory and pro-inflammatory cytokines, which are known to be important the immune response to UTI, including Interleukin (IL)-1β, IL-12(p40), and Monocyte Chemoattractant Protein-1 (MCP-1). Finally, we demonstrate that other cytokines, including IL-17 are induced significantly in the S. agalactiae-infected bladder regardless of age and parity status. Collectively, these findings show that the host environment plays an important role in influencing the severity of S. agalactiae UTI; infection dynamics, particularly in the context of bacteriuria, depend on age and parity, which also affect the nature of innate immune responses to infection.

Evaluation of tandem repeats for MLVA typing of Streptococcus uberis isolated from bovine mastitis

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Lamoureux Jérémy

2006-11-01

Full Text Available Abstract Background Streptococcus uberis is a common cause of bovine mastitis and recommended control measures, based on improved milking practice, teat dipping and antibiotic treatment at drying-off, are poorly efficient against this environmental pathogen. A simple and efficient typing method would be helpful in identifying S.uberis sources, virulent strains and cow to cow transmission. The potential of MLVA (Multiple Loci VNTR Analysis; VNTR, Variable Number of Tandem Repeats for S. uberis mastitis isolates genotyping was investigated. Results The genomic sequence of Streptococcus uberis (strain 0104J was analyzed for potential variable number tandem repeats (VNTRs. Twenty-five tandem repeats were identified and amplified by PCR with DNA samples from 24 S. uberis strains. A set of seven TRs were found to be polymorphic and used for MLVA typing of 88 S. uberis isolates. A total of 82 MLVA types were obtained with 22 types among 26 strains isolated from the milk of mastitic cows belonging to our experimental herd, and 61 types for 62 epidemiologically unrelated strains, i.e. collected in different herds and areas. Conclusion The MLVA method can be applied to S. uberis genotyping and constitutes an interesting complement to existing typing methods. This method, which is easy to perform, low cost and can be used in routine, could facilitate investigations of the epidemiology of S. uberis mastitis in dairy cows.

emm Gene Polymorphism among Streptococcus pyogenes Isolated from

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Mollaii Hamid

2009-10-01

Full Text Available DNA sequencing is the most conclusive method for emm (M protein gene typing of Streptococcus pyogenes. This method is not a feasible approach in developing countries where streptococcal infection is widespread among adults and children. Alternatively the PCR-RFLP has the potential for rapid screening of different types of S. pyogenes. To document the emm type distribution of S. pyogenes in a group of patients suffering from pharyngitis, the restriction fragment length polymorphism (RFLP profile of 50 isolates were analyzed. By using Hae III+ HincII (double digestion and Dde I restriction enzymes and based on RFLP, the profile patterns of the isolates were compared. The analysis of data identified 15 distinct RFLP patterns for Hae III+ Hinc II and 13 patterns for Dde I. They differ from each other by at least one band. Although the number of isolates was not sufficient to make any epidemiological conclusion, but the finding demonstrated that the S. pyogenes population among pateints was heterogeneous. Regarding the PCR method, we managed to improve the results by modification of CDC protocol in three different ways. This study was conducted in normal circumstances when pharyngitis was at the peak seasonal incident. However emm amplicon restriction digest analysis is a valuable tool for rapid analysis of S. pyogenes infection in more important situation like outbreaks and in selected type of study like consideration of nosocomial infection.

21 CFR 526.1696a - Penicillin G procaine.

Science.gov (United States)

2010-04-01

... treatment of mastitis caused by Streptococcus agalactiae, S. dysgalactiae, and S. uberus in lactating cows... of mastitis caused by Streptococcus agalactiae in dry cows. (3) Limitations. Discard all milk for 72... and 061623 in § 510.600(c) of this chapter. (d) Conditions of use in lactating cows—(1) Amount. Infuse...

Hibridación in situ para la detección de streptococcus agalactiae en tejidos de tilapia (oreochromis sp.)

OpenAIRE

Pulido, E. A.; Iregui, C. A.

2010-01-01

La estreptococosis es uno de los problemas sanitarios más serios en la acuicultura mundial. En Colombia la enfermedad afecta de manera importante las explotaciones de tilapia. se estandarizó la técnica de hibridación in situ (HIS ) en tejidos de tilapia previamente identificados como positivos a la presencia de S. agalactiae por la técnica de inmunoperoxidasa indirecta (IPI) y microbiología. Se obtuvo señal positiva en el interior de los granulomas con u...

Novel IgG-Degrading Enzymes of the IgdE Protease Family Link Substrate Specificity to Host Tropism of Streptococcus Species.

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Spoerry, Christian; Hessle, Pontus; Lewis, Melanie J; Paton, Lois; Woof, Jenny M; von Pawel-Rammingen, Ulrich

2016-01-01

Recently we have discovered an IgG degrading enzyme of the endemic pig pathogen S. suis designated IgdE that is highly specific for porcine IgG. This protease is the founding member of a novel cysteine protease family assigned C113 in the MEROPS peptidase database. Bioinformatical analyses revealed putative members of the IgdE protease family in eight other Streptococcus species. The genes of the putative IgdE family proteases of S. agalactiae, S. porcinus, S. pseudoporcinus and S. equi subsp. zooepidemicus were cloned for production of recombinant protein into expression vectors. Recombinant proteins of all four IgdE family proteases were proteolytically active against IgG of the respective Streptococcus species hosts, but not against IgG from other tested species or other classes of immunoglobulins, thereby linking the substrate specificity to the known host tropism. The novel IgdE family proteases of S. agalactiae, S. pseudoporcinus and S. equi showed IgG subtype specificity, i.e. IgdE from S. agalactiae and S. pseudoporcinus cleaved human IgG1, while IgdE from S. equi was subtype specific for equine IgG7. Porcine IgG subtype specificities of the IgdE family proteases of S. porcinus and S. pseudoporcinus remain to be determined. Cleavage of porcine IgG by IgdE of S. pseudoporcinus is suggested to be an evolutionary remaining activity reflecting ancestry of the human pathogen to the porcine pathogen S. porcinus. The IgG subtype specificity of bacterial proteases indicates the special importance of these IgG subtypes in counteracting infection or colonization and opportunistic streptococci neutralize such antibodies through expression of IgdE family proteases as putative immune evasion factors. We suggest that IgdE family proteases might be valid vaccine targets against streptococci of both human and veterinary medical concerns and could also be of therapeutic as well as biotechnological use.

Evaluation of CAMP-Like Effect, Biofilm Formation, and Discrimination of Candida africana from Vaginal Candida albicans Species

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Keyvan Pakshir

2017-01-01

Full Text Available Candida africana as a species recovered from female genital specimens is highly close to C. albicans. The present study was conducted to discriminate C. africana from presumptive vaginal C. albicans strains by molecular assay and evaluate their hemolysin activity, biofilm formation, and cohemolytic effect (CAMP with vaginal bacterial flora. A total of 110 stock vaginal C. albicans isolates were examined by HWP1 gene amplification. Hemolysin activity and the ability of biofilm formation were evaluated by blood plate assay and visual detection methods, respectively. Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae were used to evaluate the CAMP-like effects in Sabouraud blood agar media. Based on the size of the amplicons (941 bp, all isolates were identified as C. albicans. All samples were able to produce beta-hemolysin. Moreover, 69 out of 110 of the isolates (62.7% were biofilm-positive, 54 out of 110 Candida isolates (49% demonstrated cohemolytic effects with S. agalactiae, and 48 out of 110 showed this effect with S. aureus (43.6%. All isolates were CAMP-negative with S. epidermidis. We detected all isolates as Candida albicans and almost half of the isolates were CAMP-positive with S. aureus and S. agalactiae, suggesting that these bacteria increase the pathogenicity of Candida in vaginal candidiasis.

Evaluation of CAMP-Like Effect, Biofilm Formation, and Discrimination of Candida africana from Vaginal Candida albicans Species

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Bordbar, Mahboubeh; Nouraei, Hasti; Khodadadi, Hossein

2017-01-01

Candida africana as a species recovered from female genital specimens is highly close to C. albicans. The present study was conducted to discriminate C. africana from presumptive vaginal C. albicans strains by molecular assay and evaluate their hemolysin activity, biofilm formation, and cohemolytic effect (CAMP) with vaginal bacterial flora. A total of 110 stock vaginal C. albicans isolates were examined by HWP1 gene amplification. Hemolysin activity and the ability of biofilm formation were evaluated by blood plate assay and visual detection methods, respectively. Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus agalactiae were used to evaluate the CAMP-like effects in Sabouraud blood agar media. Based on the size of the amplicons (941 bp), all isolates were identified as C. albicans. All samples were able to produce beta-hemolysin. Moreover, 69 out of 110 of the isolates (62.7%) were biofilm-positive, 54 out of 110 Candida isolates (49%) demonstrated cohemolytic effects with S. agalactiae, and 48 out of 110 showed this effect with S. aureus (43.6%). All isolates were CAMP-negative with S. epidermidis. We detected all isolates as Candida albicans and almost half of the isolates were CAMP-positive with S. aureus and S. agalactiae, suggesting that these bacteria increase the pathogenicity of Candida in vaginal candidiasis. PMID:29318048

Salivary agglutinin, which binds Streptococcus mutans and Helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340.

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Prakobphol, A; Xu, F; Hoang, V M; Larsson, T; Bergstrom, J; Johansson, I; Frängsmyr, L; Holmskov, U; Leffler, H; Nilsson, C; Borén, T; Wright, J R; Strömberg, N; Fisher, S J

2000-12-22

Salivary agglutinin is a high molecular mass component of human saliva that binds Streptococcus mutans, an oral bacterium implicated in dental caries. To study its protein sequence, we isolated the agglutinin from human parotid saliva. After trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), which gave the molecular mass of 14 unique peptides. The remainder of the digest was subjected to high performance liquid chromatography, and the separated peptides were analyzed by MALDI-TOF/post-source decay; the spectra gave the sequences of five peptides. The molecular mass and peptide sequence information showed that salivary agglutinin peptides were identical to sequences in lung (lavage) gp-340, a member of the scavenger receptor cysteine-rich protein family. Immunoblotting with antibodies that specifically recognized either lung gp-340 or the agglutinin confirmed that the salivary agglutinin was gp-340. Immunoblotting with an antibody specific to the sialyl Le(x) carbohydrate epitope detected expression on the salivary but not the lung glycoprotein, possible evidence of different glycoforms. The salivary agglutinin also interacted with Helicobacter pylori, implicated in gastritis and peptic ulcer disease, Streptococcus agalactiae, implicated in neonatal meningitis, and several oral commensal streptococci. These results identify the salivary agglutinin as gp-340 and suggest it binds bacteria that are important determinants of either the oral ecology or systemic diseases.

Infecção congênita em cabritos por Mycoplasma agalactiae

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N.S. Silva

2014-04-01

Full Text Available This study aimed to report three cases of contagious agalactia (CA by Mycoplasma agalactiae in goat kids born with polyarthritis. The nanny goats belonging to two different herds presented clinical signs of CA during pregnancy and in parturition they were apparently healthy. The carpal articulations of the three goat kids, the tarsus articulation in one, and thigh-femoral articulation in another showed swelling, pain and impairment of the flexion-extension movements. The articular liquid was collected from two goat kids at birth and revealed a content which varied from transparent to fibrinopurulent, presenting a yellow coloring. The samples were plated on modified Hayflick. The colonies had the appearance of "fried egg" and were confirmed as being M. agalactiae by biochemical tests and 16S rRNA PCR. Blood was collected from three animals soon after birth and submitted to the indirect ELISA test for the determination of the titration of the anti- M. agalactiae antibodies. The results confirmed that the goat kids were infected during pregnancy by M. agalactiae and resulted in the birth of an offspring with clinical signs of CA being immune tolerant.

Synergism of Plant Compound With Traditional Antimicrobials Against Streptococcus spp. Isolated From Bovine Mastitis

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Natasha L. Maia

2018-06-01

Full Text Available Mastitis is an inflammation of the mammary gland that causes major losses in the dairy industry. Streptococcus spp. are among the main agents of this disease. Increased resistance to antibiotics is one of the causes of therapeutic failure. Plants, due to their broad chemodiversity, are an interesting source of new molecules with antibacterial activity. Using these compounds along with traditional antibiotics is a possible method for reversing resistance. The objective of this work was to determine the interactions between the activities of guttiferone-A and 7-epiclusianone, two active substances isolated from the fruits of Garcinia brasiliensis, and traditional antibiotics against Streptococcus spp. isolated from bovine mastitis and known to be resistant to them. First, the MIC for the antibiotics and bioactive compounds was determined, followed by their activities, alone and in combination. Then, their cytotoxicity was measured in bovine mammary epithelial cells. Finally, molecular docking simulations were performed to elucidate molecular details of the interactions between β-lactamase and the compounds binding to it (clavulanic acid, ampicillin, 7-epiclusianone, and guttiferone-A. The bacterial isolates were resistant to ampicillin and gentamicin. Both antibiotics showed predominantly synergistic antibacterial activities in combination with guttiferone-A or 7-epiclusianone. These two active substances were not cytotoxic at synergistic concentrations and both showed strong binding to β-lactamase, which may explain the reversal of ampicillin resistance. These substances are promising for the treatment of bovine mastitis.

[Group B streptococcal early-onset neonatal sepsis in the area of Barcelona (2004-2010). Analysis of missed opportunities for prevention].

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Giménez, Montserrat; Sanfeliu, Isabel; Sierra, Montserrat; Dopico, Eva; Juncosa, Teresa; Andreu, Antonia; Lite, Josep; Guardià, Cèlia; Sánchez, Ferran; Bosch, Jordi

2015-01-01

To study the evolution of the incidence of early-onset neonatal sepsis (EOS) by Streptococcus agalactiae in the area of Barcelona and to analyze failure of compliance with the prevention protocol. A retrospective review was carried out on EOS cases in 8 Health-Care Centers in the Barcelona area between 2004 and 2010. Forty-nine newborns from 48 mothers were diagnosed with EOS. The incidence was 0.29‰ living newborns (0.18-0.47‰), with no significant differences in the fluctuations along the 7 years. The mortality rate was 8.16%. In 68.5% cases the maternal colonization studies were negative, and in 21% these studies were not performed. No risk factors were detected in 58.3% of pregnant women, and 22.9% of births were premature. In 58% of cases intra-partum antibiotic prophylaxis was not administered because it was not indicated, and in 42% due to failure to follow the protocol (3 strains were resistant to erythromycin). Resistance to clindamycin was 33.3%. The Streptococcus agalactiae serotypes more frequently isolated were iii, v, and ia. No significant changes were detected in the incidence of Streptococcus agalactiae EOS in the 7 years of the study. The increased sensitivity of screening methods with the use of molecular techniques, the performance of susceptibility testing of strains isolated from pregnant women, and the improvement of communication between Health-Care Centers, can contribute to a better implementation of the protocol, as well as to reduce the incidence of EOS. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

Radioimmunoassay of serum antibodies with B-streptococcus specificity in pregnant women and infants

International Nuclear Information System (INIS)

Frey, C.W.

1980-01-01

In a specific competitive radioimmunoassay of purified rabbit antibodies, labeled with iodine 125 against group- and type-antigens of streptococcus agalactiae (streptococci type B), we investigated the amount of serum anti-bodies providing specificity of streptococci type B in not preselected pregnant women, newborn and babies with colonies of streptococci type B or with diseases due to streptococci type B and in some of their mothers. These antibodies could be detected in 26 of 45 pregnant women and in 3 of 7 children with colonies of streptococci type B. 5 of 18 newborn with the ''early-onset'' type of infection and 6 of 7 of their mothers provided antibodies with specificity of streptococci type B as did one of two newborn with the ''late onset'' type of infection. Contrary to the supposition of Baker and Kasper and in accordance with the findings of Wilkinson, the ''risk group'' cannot be determined only by detecting the antibodies against streptococci type B. The risk group comprises those persons in whom the colonisation of streptococci agalactiae leads to the frequently life-threatening infecton of neonatals with streptococci type B. (orig.) [de

Investigation of the Antimicrobial Activity of Bacillus licheniformis Strains Isolated from Retail Powdered Infant Milk Formulae.

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Alvarez-Ordóñez, Avelino; Begley, Máire; Clifford, Tanya; Deasy, Thérèse; Considine, Kiera; O'Connor, Paula; Ross, R Paul; Hill, Colin

2014-03-01

This study investigated the potential antimicrobial activity of ten Bacillus licheniformis strains isolated from retail infant milk formulae against a range of indicator (Lactococcus lactis, Lactobacillus bulgaricus and Listeria innocua) and clinically relevant (Listeria monocytogenes, Staphylococcus aureus, Streptococcus agalactiae, Salmonella Typhimurium and Escherichia coli) microorganisms. Deferred antagonism assays confirmed that all B. licheniformis isolates show antimicrobial activity against the Gram-positive target organisms. PCR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry analyses indicated that four of the B. licheniformis isolates produce the bacteriocin lichenicidin. The remaining six isolates demonstrated a higher antimicrobial potency than lichenicidin-producing strains. Further analyses identified a peptide of ~1,422 Da as the most likely bioactive responsible for the antibacterial activity of these six isolates. N-terminal sequencing of the ~1,422 Da peptide from one strain identified it as ILPEITXIFHD. This peptide shows a high homology to the non-ribosomal peptides bacitracin and subpeptin, known to be produced by Bacillus spp. Subsequent PCR analyses demonstrated that the six B. licheniformis isolates may harbor the genetic machinery needed for the synthesis of a non-ribosomal peptide synthetase similar to those involved in production of subpeptin and bacitracin, which suggests that the ~1,422 Da peptide might be a variant of subpeptin and bacitracin.

Streptococcus agalactiae Serotype IV in Humans and Cattle, Northern Europe

DEFF Research Database (Denmark)

Lyhs, Ulrike; Kulkas, Laura; Katholm, Jorgen

2016-01-01

not differentiate between populations isolated from different host species. Isolates from humans and cattle differed in lactose fermentation, which is encoded on the accessory genome and represents an adaptation to the bovine mammary gland. Serotype IV-ST196 isolates were obtained from multiple dairy herds in both...

Reappraisal of the taxonomy of Streptococcus suis serotypes 20, 22 and 26: Streptococcus parasuis sp. nov.

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Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro

2015-02-01

In order to clarify the taxonomic position of serotypes 20, 22 and 26 of Streptococcus suis, biochemical and molecular genetic studies were performed on isolates (SUT-7, SUT-286(T), SUT-319, SUT-328 and SUT-380) reacted with specific antisera of serotypes 20, 22 or 26 from the saliva of healthy pigs as well as reference strains of serotypes 20, 22 and 26. Comparative recN gene sequencing showed high genetic relatedness among our isolates, but marked differences from the type strain S. suis NCTC 10234(T), i.e. 74.8-75.7 % sequence similarity. The genomic relatedness between the isolates and other strains of species of the genus Streptococcus, including S. suis, was calculated using the average nucleotide identity values of whole genome sequences, which indicated that serotypes 20, 22 and 26 should be removed taxonomically from S. suis and treated as a novel genomic species. Comparative sequence analysis revealed 99.0-100 % sequence similarities for the 16S rRNA genes between the reference strains of serotypes 20, 22 and 26, and our isolates. Isolate STU-286(T) had relatively high 16S rRNA gene sequence similarity with S. suis NCTC 10234(T) (98.8 %). SUT-286(T) could be distinguished from S. suis and other closely related species of the genus Streptococcus using biochemical tests. Due to its phylogenetic and phenotypic similarities to S. suis we propose naming the novel species Streptococcus parasuis sp. nov., with SUT-286(T) ( = JCM 30273(T) = DSM 29126(T)) as the type strain. © 2015 IUMS.

Molecular epidemiology of group A streptococcus from pharyngeal isolates in Auckland, New Zealand, 2013.

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Williamson, Deborah A; Moreland, Nicole J; Carter, Philip; Upton, Arlo; Morgan, Julie; Proft, Thomas; Lennon, Diana; Baker, Michael G; Dunbar, Rod; Fraser, John D

2014-01-24

To describe the molecular epidemiology of emm types associated with circulating pharyngeal group A streptococcus (GAS) isolates in Auckland, New Zealand. GAS isolates were collected over a 10-day period from a community pathology provider in Auckland. PCR analysis and sequencing of the emm gene was performed at the Institute of Environmental Science and Research. A total of 52 emm types were identified from 278 GAS isolates. The three most common emm types were emm1, emm89 and emm12. Overall, the experimental 30-valent GAS M protein vaccine covered 19 / 52 (37%) of emm types in our study. Our study provides baseline data on the circulating pharyngeal GAS emm types in Auckland. Future clinical and molecular surveillance of GAS pharyngitis is essential in the context of ongoing GAS vaccine development.

Whole-Genome Sequence Analysis of Antimicrobial Resistance Genes in Streptococcus uberis and Streptococcus dysgalactiae Isolates from Canadian Dairy Herds

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Julián Reyes Vélez

2017-05-01

Full Text Available The objectives of this study are to determine the occurrence of antimicrobial resistance (AMR genes using whole-genome sequence (WGS of Streptococcus uberis (S. uberis and Streptococcus dysgalactiae (S. dysgalactiae isolates, recovered from dairy cows in the Canadian Maritime Provinces. A secondary objective included the exploration of the association between phenotypic AMR and the genomic characteristics (genome size, guanine–cytosine content, and occurrence of unique gene sequences. Initially, 91 isolates were sequenced, and of these isolates, 89 were assembled. Furthermore, 16 isolates were excluded due to larger than expected genomic sizes (>2.3 bp × 1,000 bp. In the final analysis, 73 were used with complete WGS and minimum inhibitory concentration records, which were part of the previous phenotypic AMR study, representing 18 dairy herds from the Maritime region of Canada (1. A total of 23 unique AMR gene sequences were found in the bacterial genomes, with a mean number of 8.1 (minimum: 5; maximum: 13 per genome. Overall, there were 10 AMR genes [ANT(6, TEM-127, TEM-163, TEM-89, TEM-95, Linb, Lnub, Ermb, Ermc, and TetS] present only in S. uberis genomes and 2 genes unique (EF-TU and TEM-71 to the S. dysgalactiae genomes; 11 AMR genes [APH(3′, TEM-1, TEM-136, TEM-157, TEM-47, TetM, bl2b, gyrA, parE, phoP, and rpoB] were found in both bacterial species. Two-way tabulations showed association between the phenotypic susceptibility to lincosamides and the presence of linB (P = 0.002 and lnuB (P < 0.001 genes and the between the presence of tetM (P = 0.015 and tetS (P = 0.064 genes and phenotypic resistance to tetracyclines only for the S. uberis isolates. The logistic model showed that the odds of resistance (to any of the phenotypically tested antimicrobials was 4.35 times higher when there were >11 AMR genes present in the genome, compared with <7 AMR genes (P < 0.001. The odds of resistance was lower for S

Antimicrobial resistance and molecular epidemiology of streptococci from bovine mastitis

DEFF Research Database (Denmark)

Rato, Márcia G.; Bexiga, Ricardo; Florindo, Carlos

2013-01-01

Streptococcus agalactiae (Group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (Group C Streptococcus, GCS) and Streptococcus uberis are relevant mastitis pathogens, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production. T...

Evaluation of antibacterial effect of some Sinai medicinal plant extracts on bacteria isolated from bovine mastitis

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Gamil S. G. Zeedan

2014-11-01

Full Text Available Aim: Bovine mastitis is the most economically important disease affecting dairy cattle worldwide from an economic, diagnostic and public-health point of view. The present study aimed to isolate and identify of bacteria causes mastitis in dairy cows and to evaluate the antibacterial activities of some selected medicinal plants extracts comparing antibiotics used in the treatment of mastitis in Egypt. Materials and Methods: A total of 203 milk samples of dairy cows were collected during the period from February to June 2013 at different Governorates in Egypt. The use clinical inspection and California mastitis test examination were provided efficient diagnostic tool for detection of clinical, subclinical mastitis and apparently normal health cattle. The collected milk samples were cultured on Nutrient, Blood agar, Mannitol salt, Edward’s and MacConkey agar plates supporting the growth of various types of bacteria for their biochemical studies and isolation. The antimicrobial activity of plants extracts (Jasonia montana and Artemisia herb albawith different solvent (ethanol, petroleum ether, chloroform and acetonewere studied in vitro against isolated bacteria from mastitis by paper desk diffusion and minimum inhibitory concentration method (MIC. Results: The prevalence of clinical, subclinical mastitis and normal healthy animals were 34.50%, 24.7% and 40.8% respectively. The major pathogens isolated from collected milk samples were Escherichia coli (22.16%, Staphylococcus aureus (20.19%, Streptococcus spp. (13.3%, Streptococcus agalactiae (12.8%, Streptococcus dysgalactia (0.5%, Pasteurella spp. (2.45%, Klebsiella spp. (1.47%and Pseudomonas spp. (0.45%. The highest antibacterial activity of J. montana plant extracted with acetone solvent against S. agalactiae, E. coli, S. aureus, Klebsiella spp and coagulase-negative Staphylococci with zone of inhibition values ± standard deviation (SD, ranging from 4.33±0.57 to 25.6±0.60 mm. The MIC values

Comparative genome analysis of Streptococcus infantarius subsp. infantarius CJ18, an African fermented camel milk isolate with adaptations to dairy environment.

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Jans, Christoph; Follador, Rainer; Hochstrasser, Mira; Lacroix, Christophe; Meile, Leo; Stevens, Marc J A

2013-03-22

Streptococcus infantarius subsp. infantarius (Sii) belongs to the Streptococcus bovis/Streptococcus equinus complex associated with several human and animal infections. Sii is a predominant bacterium in spontaneously fermented milk products in Africa. The genome sequence of Sii strain CJ18 was compared with that of other Streptococcus species to identify dairy adaptations including genome decay such as in Streptococcus thermophilus, traits for its competitiveness in spontaneous milk fermentation and to assess potential health risks for consumers. The genome of Sii CJ18 harbors several unique regions in comparison to Sii ATCC BAA-102T, among others an enlarged exo- and capsular polysaccharide operon; Streptococcus thermophilus-associated genes; a region containing metabolic and hypothetical genes mostly unique to CJ18 and the dairy isolate Streptococcus gallolyticus subsp. macedonicus; and a second oligopeptide transport operon. Dairy adaptations in CJ18 are reflected by a high percentage of pseudogenes (4.9%) representing genome decay which includes the inactivation of the lactose phosphotransferase system (lacIIABC) by multiple transposases integration. The presence of lacS and lacZ genes is the major dairy adaptation affecting lactose metabolism pathways also due to the disruption of lacIIABC.We constructed mutant strains of lacS, lacZ and lacIIABC and analyzed the resulting strains of CJ18 to confirm the redirection of lactose metabolism via LacS and LacZ.Natural competence genes are conserved in both Sii strains, but CJ18 contains a lower number of CRISPR spacers which indicates a reduced defense capability against alien DNA. No classical streptococcal virulence factors were detected in both Sii strains apart from those involved in adhesion which should be considered niche factors. Sii-specific virulence factors are not described. Several Sii-specific regions encoding uncharacterized proteins provide new leads for virulence analyses and investigation of the

Comparative genome analysis of Streptococcus infantarius subsp. infantarius CJ18, an African fermented camel milk isolate with adaptations to dairy environment

Science.gov (United States)

2013-01-01

Background Streptococcus infantarius subsp. infantarius (Sii) belongs to the Streptococcus bovis/Streptococcus equinus complex associated with several human and animal infections. Sii is a predominant bacterium in spontaneously fermented milk products in Africa. The genome sequence of Sii strain CJ18 was compared with that of other Streptococcus species to identify dairy adaptations including genome decay such as in Streptococcus thermophilus, traits for its competitiveness in spontaneous milk fermentation and to assess potential health risks for consumers. Results The genome of Sii CJ18 harbors several unique regions in comparison to Sii ATCC BAA-102T, among others an enlarged exo- and capsular polysaccharide operon; Streptococcus thermophilus-associated genes; a region containing metabolic and hypothetical genes mostly unique to CJ18 and the dairy isolate Streptococcus gallolyticus subsp. macedonicus; and a second oligopeptide transport operon. Dairy adaptations in CJ18 are reflected by a high percentage of pseudogenes (4.9%) representing genome decay which includes the inactivation of the lactose phosphotransferase system (lacIIABC) by multiple transposases integration. The presence of lacS and lacZ genes is the major dairy adaptation affecting lactose metabolism pathways also due to the disruption of lacIIABC. We constructed mutant strains of lacS, lacZ and lacIIABC and analyzed the resulting strains of CJ18 to confirm the redirection of lactose metabolism via LacS and LacZ. Natural competence genes are conserved in both Sii strains, but CJ18 contains a lower number of CRISPR spacers which indicates a reduced defense capability against alien DNA. No classical streptococcal virulence factors were detected in both Sii strains apart from those involved in adhesion which should be considered niche factors. Sii-specific virulence factors are not described. Several Sii-specific regions encoding uncharacterized proteins provide new leads for virulence analyses and

Mixed infection zones may be important in the epidemiology of contagious agalactia

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Jafarizadeh Amirreza

2016-06-01

Full Text Available Introduction: The current study was designed to detect Mycoplasma agalactiae (Ma, Mycoplasma mycoides subsp. capri (Mmc, Mycoplasma capricolum subsp. capricolum (Mcc and Mycoplasma putrefaciens (Mp in sheep and goats with clinical signs consistent with contagious agalactia.

Genetic diversity of Streptococcus suis isolates as determined by comparative genome hybridization

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Thi Hoa

2011-07-01

Full Text Available Abstract Background Streptococcus suis is a zoonotic pathogen that causes infections in young piglets. S. suis is a heterogeneous species. Thirty-three different capsular serotypes have been described, that differ in virulence between as well as within serotypes. Results In this study, the correlation between gene content, serotype, phenotype and virulence among 55 S. suis strains was studied using Comparative Genome Hybridization (CGH. Clustering of CGH data divided S. suis isolates into two clusters, A and B. Cluster A isolates could be discriminated from cluster B isolates based on the protein expression of extracellular factor (EF. Cluster A contained serotype 1 and 2 isolates that were correlated with virulence. Cluster B mainly contained serotype 7 and 9 isolates. Genetic similarity was observed between serotype 7 and serotype 2 isolates that do not express muramidase released protein (MRP and EF (MRP-EF-, suggesting these isolates originated from a common founder. Profiles of 25 putative virulence-associated genes of S. suis were determined among the 55 isolates. Presence of all 25 genes was shown for cluster A isolates, whereas cluster B isolates lacked one or more putative virulence genes. Divergence of S. suis isolates was further studied based on the presence of 39 regions of difference. Conservation of genes was evaluated by the definition of a core genome that contained 78% of all ORFs in P1/7. Conclusions In conclusion, we show that CGH is a valuable method to study distribution of genes or gene clusters among isolates in detail, yielding information on genetic similarity, and virulence traits of S. suis isolates.

[Identification and detection of trag: a new infection-related gene expressed in vivo from isolates of Streptococcus suis].

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Zhu, Haodan; Gu, Hongwei; Lu, Chengping

2008-12-01

The trag (transfer gene G) was one of the novel infection-related factors identified by in vivo-induced antigen technology (IVIAT) from Streptococcus suis type 2 expression libraries with swine convalesecent sera in our former research. We detected the distribution of trag in different Streptococcus suis isolates and identify the differential expression of the new infection-related factor between in vivo and in vitro condition. According to the sequence of trag of North American strain 89/1591, a pair of primers were designed to detect the distribution of trag in total 43 SS isolates. Another pair of primers were designed to amplify the ORF of trag of 5 SS representive strains (ZY05719, HA9801, 98012, SH040805, SH040917). Partial gene of trag was cloned and inserted into expression vector pET28a(+), and induced by IPTG to express recombinant TRAG. The recombinant protein was probed with swine convalescent sera and immune sera respectively. The trag was detected in the most of SS2 isolates (30/32), in SS9 isolates (4/6), and 1 isolate of SS7, while it was not found in SS2 European strain ATCC43765, avirulent strain SS2 T15, 1 isolates of SS1, 1 isolates of SS1/2 and 2 isolates of group C streptococcal strains from pigs. Comparisons between the sequences of TRAG of 5 isolates with that of SS isolates, showed a high homology (>97%) with North American strain 89/1589 and China strains 98HAH33, 05ZYH33. The immunoreactivity was only presented with convalescent sera. The trag was detected from virulent SS isolates but not from avirulent strain, which suggested that this gene may be related to the pathogenicity of SS. The special reactivity was only present with convalescent sera, and it indicated that TRAG might play a role during SS2 invasive course.

Incidence of clinical mastitis and distribution of pathogens on large Chinese dairy farms.

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Gao, Jian; Barkema, Herman W; Zhang, Limei; Liu, Gang; Deng, Zhaoju; Cai, Lingjie; Shan, Ruixue; Zhang, Shiyao; Zou, Jiaqi; Kastelic, John P; Han, Bo

2017-06-01

Knowledge of the incidence of clinical mastitis (CM) and the distribution of pathogens involved is essential for development of prevention and control programs as well as treatment protocols. No country-wide study on the incidence of CM and the distribution of pathogens involved has been conducted in China. Core objectives of this study were, therefore, to determine the cumulative incidence of CM and the distribution of pathogens causing CM on large Chinese (>500 cows) dairy farms. In addition, associations between the distribution of CM pathogens and bedding materials and seasonal factors were also investigated. Bacterial culture was done on a total of 3,288 CM quarter milk samples from 161 dairy herds (located in 21 provinces) between March 2014 and September 2016. Additional data, including geographical region of herds, herd size, bedding types, and number of CM cases during the last month, were also recorded. Mean cumulative incidence of CM was 3.3 cases per 100 cows per month (range = 1.7 to 8.1). The most frequently isolated pathogens were Escherichia coli (14.4%), Klebsiella spp. (13.0%), coagulase-negative staphylococci (11.3%), Streptococcus dysgalactiae (10.5%), and Staphylococcus aureus (10.2%). Streptococcus agalactiae was isolated from 2.8% of CM samples, whereas Streptococcus uberis were isolated from 2.1% of samples, and 15.8% of 3,288 samples were culture-negative. Coagulase-negative staphylococci, E. coli, and other Enterobacter spp. were more frequently isolated in the northwest than the northeast or south of China. Streptococcus dysgalactiae, other streptococci, and Strep. agalactiae were more frequently isolated in winter (October-March), whereas E. coli and Klebsiella spp. were mostly isolated in summer (April-September). Streptococcus dysgalactiae was more often isolated from CM cases of herds using sand bedding, whereas Klebsiella spp. and other streptococci were more common in herds using organic bedding. The incidence of CM and distribution

Lysogenic Streptococcus suis isolate SS2-4 containing prophage SMP showed increased mortality in zebra fish compared to the wild-type isolate.

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Fang Tang

Full Text Available Streptococcus suis (S. suis infection is considered to be a major problem in the swine industry worldwide. Based on the capsular type, 33 serotypes of S. suis have been described, with serotype 2 (SS2 being the most frequently isolated from diseased piglets. Little is known, however, about the pathogenesis and virulence factors of S. suis. Research on bacteriophages highlights a new area in S. suis research. A S. suis serotype 2 bacteriophage, designated SMP, has been previously isolated in our laboratory. Here, we selected a lysogenic isolate in which the SMP phage was integrated into the chromosome of strain SS2-4. Compared to the wild-type isolate, the lysogenic strain showed increased mortality in zebra fish. Moreover the sensitivity of the lysogenic strain to lysozyme was seven times higher than that of the wild-type.

[Sensitivity profile of Staphylococcus spp. and Streptococcus spp. isolated from toys used in a teaching hospital playroom].

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Boretti, Vanessa Stolf; Corrêa, Renata Nunes; dos Santos, Silvana Soléo Ferreira; Leão, Mariella Vieira Pereira; Gonçalves e Silva, Célia Regina

2014-09-01

To evaluate the presence of microorganisms of the genus Staphylococcus and Streptococcus on toys in the playroom of a teaching hospital, as well to as analyze the antimicrobial from the isolated strains. Samples were collected from 60 toys, using wet swabs, soon after being used by the children. The samples were inoculated in enriched and selective agar for isolation and later identification of the microorganisms. Antibiogram testing was performed by agar diffusion technique. The genus Staphylococcus was present in 87.0% (52/60) of the toys. Seventythree strains were isolated, with 29.0% (21/73) coagulase-positive and 71.0% (52/73) coagulase-negative. Among the coagulase-negative strains, 90.4% were resistant to penicillin, 65.4% to oxacillin, 28.8% to clarithromycin, 61.5% to clindamycin, and none to vancomycin. Among the coagulase-positive strains, 76.2% were resistant to penicillin, 23.8% to oxacillin, 23.8% to clarithromycin, 47.6% to clindamycin, and none to vancomycin. The genus Streptococcus was not detected in any of the evaluated toys. Toys can be contaminated with potentially pathogenic bacteria with antimicrobial resistance, representing a possible source of nosocomial infection for patients who are already debilitated. Copyright © 2014 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

Sensitivity profile of Staphylococcus spp. and Streptococcus spp. isolated from toys used in a teaching hospital playroom☆

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Boretti, Vanessa Stolf; Corrêa, Renata Nunes; dos Santos, Silvana Soléo Ferreira; Leão, Mariella Vieira Pereira; Silva, Célia Regina Gonçalves e

2014-01-01

Objective: To evaluate the presence of microorganisms of the genus Staphylococcus and Streptococcus on toys in the playroom of a teaching hospital, as well to as analyze the antimicrobial resistance from isolated strains. Methods: Samples were collected from 60 toys, using wet swabs, soon after being used by the children. The samples were inoculated in enriched and selective agar for isolation and later identification of the microorganisms. Antibiogram testing was performed by agar diffusion technique. Results: The genus Staphylococcus was present in 87.0% (52/60) of the toys. Seventy-three strains were isolated, with 29.0% (21/73) coagulase-positive and 71.0% (52/73) coagulasenegative. Among the coagulase-negative strains, 90.4% were resistant to penicillin, 65.4% to oxacillin, 28.8% to clarithromycin, 61.5% to clindamycin, and none to vancomycin. Among the coagulase-positive strains, 76.2% were resistant to penicillin, 23.8% to oxacillin, 23.8% to clarithromycin, 47.6% to clindamycin, and none to vancomycin. The genus Streptococcus was not detected in any of the evaluated toys. Conclusions: Toys can be contaminated with potentially pathogenic bacteria with antimicrobial resistance, representing a possible source of nosocomial infection for patients who are already debilitated. PMID:25479842

Genotypic Characterization of Streptococcus infantarius subsp. coli Isolates from Sea Otters with Infective Endocarditis and/or Septicemia and from Environmental Mussel Samples

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Counihan-Edgar, Katrina L.; Gill, Verena A.; Doroff, Angela M.; Burek, Kathleen A.; Miller, Woutrina A.; Shewmaker, Patricia L.; Jang, Spencer; Goertz, Caroline E. C.; Tuomi, Pamela A.; Miller, Melissa A.; Jessup, David A.

2012-01-01

Pulsed-field gel electrophoresis (PFGE) was used to type 128 Streptococcus infantarius subsp. coli isolates from sea otters and mussels. Six SmaI PFGE groups were detected, with one predominant group representing 57% of the isolates collected over a wide geographic region. Several sea otter and mussel isolates were highly related, suggesting that an environmental infection source is possible. PMID:23052307

Influencia de la composición del medio de cultivo sobre la producción de pigmento por Streptococcus agalactiae

OpenAIRE

Carazo Carazo, Concepción

2011-01-01

Se ha estudiado la influencia de la composición del medio de cultivo sobre la producción de pigmento por s. agalactiae partiendo de un medio de cultivo diseñado para tal finalidad (new granada medium), eliminando uno a uno los componentes incluidos en su formulación original. Almidón, proteosa peptona (difco), suero, fosfatos y metrotexato influyen de forma importante en la formación y/o visualización del pigmento producido por este microorganismo. Se ha determinado que la fracción de proteos...

PENAPISAN ISOLAT BAKTERI Streptococcus spp. SEBAGAI KANDIDAT ANTIGEN DALAM PEMBUATAN VAKSIN, SERTA EFIKASINYA UNTUK PENCEGAHAN PENYAKIT STREPTOCOCCOSIS PADA IKAN NILA, Oreochromis niloticus

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Taukhid Taukhid

2011-04-01

Full Text Available Riset dengan tujuan untuk memperoleh isolat kandidat yang imunogenik bagi pembuatan vaksin untuk pengendalian penyakit streptococcosis pada ikan nila telah dilakukan. Karakterisasi dilakukan secara biokimia dan API 20 STREP terhadap 15 isolat bakteri Streptococcus spp. Uji Koch’s Postulate kemudian dilakukan untuk mengetahui peran bakteri pada infeksi streptococcosis pada ikan nila. Konfirmasi taksonomis hingga level spesies isolat bakteri S. agalactiae dilakukan dengan teknik Polymerase Chain Reaction (PCR dengan menggunakan primer spesifik. Uji patogenisitas dilakukan terhadap 6 isolat yang terdiri atas 5 isolat S. agalactiae (N3M, N4M, N14G, N17O, NK1 dan 1 isolat S. iniae (N2O. Hasil penapisan menunjukkan bahwa bakteri S. agalactiae (N4M memiliki nilai LD50 terkecil, dan nilai terbesar dimiliki oleh bakteri S. iniae (N2O. Isolat bakteri N4M digunakan sebagai sumber antigen dalam pembuatan vaksin anti streptococcosis. Vaksin disiapkan dalam bentuk sel utuh dan diinaktivasi dengan formalin, pemanasan, dan sonikasi. Nilai titer antibodi dan sintasan tertinggi diperoleh pada kelompok ikan yang divaksin dengan formalin killed vaccine dibandingkan dengan teknik inaktivasi lainnya (heat killed vaccine dan sonicated vaccine.

Pathogens associated with bovine mastitis in dairy herds in the south region of Brazil

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Marta Bañolas Jobim

2010-02-01

Full Text Available In this work, through microbiological examinations, the etiology of bovine mastitis in 628 milk samples coming from dairy farms from Paraná, Santa Catarina and Rio Grande do Sul along the year of 2007 were evaluated. Out of this total 1,382 microorganisms were isolated. By taking into account the total of isolations, the following microorganisms and their percentage, respectively were found: Staphylococcus spp. (30.53%, Escherichia coli (21.64%, Streptococcus bovis (17.08%, Streptococcus agalactiae (11.07%, Enterobacter spp. (7.53%, Pseudomonas spp. (4.12% and others (8.03%. The microorganisms grouped into the others are: Streptococcus spp., Proteus spp., gram negative rods, Shigella spp., Alcaligenes spp., Klebsiella spp., Edwarsiella spp., Citrobacter spp., Serratia spp., Salmonella spp. e Corynebacterium spp. The environmental pathogens predominated among the isolated microorganisms; 33.13% of the cultures presented more than three pathogens, suggesting contamination of the samples; in the mounts of November and December, there was an increase of the samples sent.

Draft genome sequence of Streptococcus equi subsp. zooepidemicus strain S31A1, isolated from equine infectious endometritis

DEFF Research Database (Denmark)

da Piedade, Isabelle; Skive, Bolette; Christensen, Henrik

2013-01-01

We present the draft genome sequence of Streptococcus equi subsp. zooepidemicus S31A1, a strain isolated from equine infectious endometritis in Denmark. Comparative analyses of this genome were done with four published reference genomes: S. zooepidemicus strains MGCS10565, ATCC 35246, and H70 and S...

Use of MALDI-TOF Mass Spectrometry for the Fast Identification of Gram-Positive Fish Pathogens

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Assis, Gabriella B. N.; Pereira, Felipe L.; Zegarra, Alexandra U.; Tavares, Guilherme C.; Leal, Carlos A.; Figueiredo, Henrique C. P.

2017-01-01

Gram-positive cocci, such as Streptococcus agalactiae, Lactococcus garvieae, Streptococcus iniae, and Streptococcus dysgalactiae subsp. dysgalactiae, are found throughout the world, particularly in outbreaks in farmed fish, and are thus associated with high economic losses, especially in the cultivation of Nile Tilapia. The aim of this study was to evaluate the efficacy of matrix-assisted laser desorption ionization (MALDI)-time of flight (TOF) mass spectrometry (MS) as an alternative for the diagnosis of these pathogens. One hundred and thirty-one isolates from Brazilian outbreaks assisted by the national authority were identified using a MALDI Biotyper from Bruker Daltonics. The results showed an agreement with respect to identification (Kappa = 1) between this technique and 16S ribosomal RNA gene sequencing for S. agalactiae and L. garvieae. However, for S. iniae and S. dysgalactiae subsp. dysgalactiae, perfect agreement was only achieved after the creation of a custom main spectra profile, as well as further comparisons with 16S ribosomal RNA and multilocus sequence analysis. MALDI-TOF MS was shown to be an efficient technology for the identification of these Gram-positive pathogens, yielding a quick and precise diagnosis. PMID:28848512

Clonal relationships among penicillin-susceptible, multiresistant serotype 6B Streptococcus pneumoniae isolates recovered in Greece and France.

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Syrogiannopoulos, G A; Doit, C; Grivea, I N; Geslin, P; Bingen, E

2001-01-01

In January 1996 the emergence of penicillin-susceptible, multiresistant serotype 6B Streptococcus pneumoniae isolates resistant to chloramphenicol, tetracycline, erythromycin, clindamycin and trimethoprim-sulfamethoxazole was observed in young carriers in the city of Patras, located in the southwestern region of Greece. Later, a significant spread of pneumococci with this unusual phenotype was noted in carriers living in various other areas of the country. Using restriction fragment length polymorphism of the ribosomal RNA genes, clonal relationships were found between these Greek strains and serotype 6B penicillin-susceptible, multiresistant pneumococci isolated in France between January 1992 and September 1996. The French and Greek isolates appear to have a common ancestry.

Activities of Tedizolid and Linezolid Determined by the Reference Broth Microdilution Method against 3,032 Gram-Positive Bacterial Isolates Collected in Asia-Pacific, Eastern Europe, and Latin American Countries in 2014.

Science.gov (United States)

Pfaller, Michael A; Flamm, Robert K; Jones, Ronald N; Farrell, David J; Mendes, Rodrigo E

2016-09-01

Tedizolid and linezolid in vitro activities against 3,032 Gram-positive pathogens collected in Asia-Pacific, Eastern European, and Latin American medical centers during 2014 were assessed. The isolates were tested for susceptibility by the current reference broth microdilution methods. Due to concern over the effect of MIC endpoint criteria on the results of testing the oxazolidinones tedizolid and linezolid, MIC endpoint values were read by two methods: (i) reading the MIC at the first well where the trailing began without regard for pinpoint trailing, according to CLSI M07-A10 and M100-S26 document instructions for reading linezolid (i.e., 80% inhibition of growth; these reads were designated tedizolid 80 and linezolid 80), and (ii) at 100% inhibition of growth (designated tedizolid 100 and linezolid 100). All Staphylococcus aureus, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus anginosus group, and Enterococcus faecalis isolates were inhibited at tedizolid 80 and 100 MIC values of 0.25 and 0.5, 0.25 and 0.25, 0.25 and 0.5, 0.12 and 0.25, and 0.5 and 1 μg/ml, respectively. Generally, MIC50 and MIC90 results for tedizolid 80 and linezolid 80 were one doubling dilution lower than those read at 100% inhibition. Tedizolid was 4- to 8-fold more potent than linezolid against all the isolates tested regardless of the MIC endpoint criterion used. Despite the differences in potency, >99.9% of isolates tested in this survey were susceptible to both linezolid and tedizolid using CLSI and EUCAST interpretive criteria. In conclusion, tedizolid demonstrated greater in vitro potency than linezolid against Gram-positive pathogens isolated from patients in medical centers across the Asia-Pacific region, Eastern Europe, and Latin America. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Phenotypic Heterogeneity of Genomically-Diverse Isolates of Streptococcus mutans

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Palmer, Sara R.; Miller, James H.; Abranches, Jacqueline; Zeng, Lin; Lefebure, Tristan; Richards, Vincent P.; Lemos, José A.; Stanhope, Michael J.; Burne, Robert A.

2013-01-01

High coverage, whole genome shotgun (WGS) sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat) and exposure to competence stimulating peptide (CSP). Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease. PMID:23613838

Phenotypic heterogeneity of genomically-diverse isolates of Streptococcus mutans.

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Sara R Palmer

Full Text Available High coverage, whole genome shotgun (WGS sequencing of 57 geographically- and genetically-diverse isolates of Streptococcus mutans from individuals of known dental caries status was recently completed. Of the 57 sequenced strains, fifteen isolates, were selected based primarily on differences in gene content and phenotypic characteristics known to affect virulence and compared with the reference strain UA159. A high degree of variability in these properties was observed between strains, with a broad spectrum of sensitivities to low pH, oxidative stress (air and paraquat and exposure to competence stimulating peptide (CSP. Significant differences in autolytic behavior and in biofilm development in glucose or sucrose were also observed. Natural genetic competence varied among isolates, and this was correlated to the presence or absence of competence genes, comCDE and comX, and to bacteriocins. In general strains that lacked the ability to become competent possessed fewer genes for bacteriocins and immunity proteins or contained polymorphic variants of these genes. WGS sequence analysis of the pan-genome revealed, for the first time, components of a Type VII secretion system in several S. mutans strains, as well as two putative ORFs that encode possible collagen binding proteins located upstream of the cnm gene, which is associated with host cell invasiveness. The virulence of these particular strains was assessed in a wax-worm model. This is the first study to combine a comprehensive analysis of key virulence-related phenotypes with extensive genomic analysis of a pathogen that evolved closely with humans. Our analysis highlights the phenotypic diversity of S. mutans isolates and indicates that the species has evolved a variety of adaptive strategies to persist in the human oral cavity and, when conditions are favorable, to initiate disease.

Udder pathogens and their resistance to antimicrobial agents in dairy cows in Estonia

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Orro Toomas

2011-02-01

Full Text Available Abstract Background The goal of this study was to estimate the distribution of udder pathogens and their antibiotic resistance in Estonia during the years 2007-2009. Methods The bacteriological findings reported in this study originate from quarter milk samples collected from cows on Estonian dairy farms that had clinical or subclinical mastitis. The samples were submitted by local veterinarians to the Estonian Veterinary and Food Laboratory during 2007-2009. Milk samples were examined by conventional bacteriology. In vitro antimicrobial susceptibility testing was performed with the disc diffusion test. Logistic regression with a random herd effect to control for clustering was used for statistical analysis. Results During the study period, 3058 clinical mastitis samples from 190 farms and 5146 subclinical mastitis samples from 274 farms were investigated. Positive results were found in 57% of the samples (4680 out of 8204, and the proportion did not differ according to year (p > 0.05. The proportion of bacteriologically negative samples was 22.3% and that of mixed growth was 20.6%. Streptococcus uberis (Str. uberis was the bacterium isolated most frequently (18.4% from cases of clinical mastitis, followed by Escherichia coli (E. coli (15.9% and Streptococcus agalactiae (Str. agalactiae (11.9%. The bacteria that caused subclinical mastitis were mainly Staphylococcus aureus (S. aureus (20% and coagulase-negative staphylococci (CNS (15.4%. The probability of isolating S. aureus from milk samples was significantly higher on farms that had fewer than 30 cows, when compared with farms that had more than 100 cows (p Str. agalactiae infection was found on farms with more than 600 cows (p = 0.034 compared with smaller farms. The proportion of S. aureus and CNS isolates that were resistant to penicillin was 61.4% and 38.5%, respectively. Among the E. coli isolates, ampicillin, streptomycin and tetracycline resistance were observed in 24.3%, 15.6% and 13

Characterization of a new CAMP factor carried by an integrative and conjugative element in Streptococcus agalactiae and spreading in Streptococci.

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Sarah Chuzeville

Full Text Available Genetic exchanges between Streptococci occur frequently and contribute to their genome diversification. Most of sequenced streptococcal genomes carry multiple mobile genetic elements including Integrative and Conjugative Elements (ICEs that play a major role in these horizontal gene transfers. In addition to genes involved in their mobility and regulation, ICEs also carry genes that can confer selective advantages to bacteria. Numerous elements have been described in S. agalactiae especially those integrated at the 3' end of a tRNA(Lys encoding gene. In strain 515 of S. agalactiae, an invasive neonate human pathogen, the ICE (called 515_tRNA(Lys is functional and carries different putative virulence genes including one encoding a putative new CAMP factor in addition to the one previously described. This work demonstrated the functionality of this CAMP factor (CAMP factor II in Lactococcus lactis but also in pathogenic strains of veterinary origin. The search for co-hemolytic factors in a collection of field strains revealed their presence in S. uberis, S. dysgalactiae, but also for the first time in S. equisimilis and S. bovis. Sequencing of these genes revealed the prevalence of a species-specific factor in S. uberis strains (Uberis factor and the presence of a CAMP factor II encoding gene in S. bovis and S. equisimilis. Furthermore, most of the CAMP factor II positive strains also carried an element integrated in the tRNA(Lys gene. This work thus describes a CAMP factor that is carried by a mobile genetic element and has spread to different streptococcal species.

Group B Streptococcus Induces Neutrophil Recruitment to Gestational Tissues and Elaboration of Extracellular Traps and Nutritional Immunity.

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Kothary, Vishesh; Doster, Ryan S; Rogers, Lisa M; Kirk, Leslie A; Boyd, Kelli L; Romano-Keeler, Joann; Haley, Kathryn P; Manning, Shannon D; Aronoff, David M; Gaddy, Jennifer A

2017-01-01

Streptococcus agalactiae , or Group B Streptococcus (GBS), is a gram-positive bacterial pathogen associated with infection during pregnancy and is a major cause of morbidity and mortality in neonates. Infection of the extraplacental membranes surrounding the developing fetus, a condition known as chorioamnionitis, is characterized histopathologically by profound infiltration of polymorphonuclear cells (PMNs, neutrophils) and greatly increases the risk for preterm labor, stillbirth, or neonatal GBS infection. The advent of animal models of chorioamnionitis provides a powerful tool to study host-pathogen relationships in vivo and ex vivo . The purpose of this study was to evaluate the innate immune response elicited by GBS and evaluate how antimicrobial strategies elaborated by these innate immune cells affect bacteria. Our work using a mouse model of GBS ascending vaginal infection during pregnancy reveals that clinically isolated GBS has the capacity to invade reproductive tissues and elicit host immune responses including infiltration of PMNs within the choriodecidua and placenta during infection, mirroring the human condition. Upon interacting with GBS, murine neutrophils elaborate DNA-containing extracellular traps, which immobilize GBS and are studded with antimicrobial molecules including lactoferrin. Exposure of GBS to holo- or apo-forms of lactoferrin reveals that the iron-sequestration activity of lactoferrin represses GBS growth and viability in a dose-dependent manner. Together, these data indicate that the mouse model of ascending infection is a useful tool to recapitulate human models of GBS infection during pregnancy. Furthermore, this work reveals that neutrophil extracellular traps ensnare GBS and repress bacterial growth via deposition of antimicrobial molecules, which drive nutritional immunity via metal sequestration strategies.

Multicentre epidemiological survey on the incidence of Streptococcus agalactiae in pregnancy

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Leonardo Lodolo

2010-03-01

Full Text Available ß-hemolytic streptococci group B (GBS cause infections of the urinary tract, endometrium, amnion, and superinfection of wounds, with complications in 2% -4% of cases in pregnant woman.The infection transmitted to newborns is a cause of sepsis and meningitis with high incidence of mortality.A recent report on a multicentric study of the ISS, showed that detection of S. agalactiae in pregnant women in different realities of healthcare, ranging from 3.9% to 19.4%. This survey covers a sample of 29607 women screened in a total of 36852 childbirths, with a positivity of 4183 subjects equal to 14.1%. Thanks to the GBS Study Group of Piemonte and Valle d’Aosta microbiology laboratories, with the support of 42 study centres have been involved. Collection techniques, types of medium, environmental of incubation of the culture, possible enrichment in broth, of the swabs of 28491 women during 2006/2007 have been considered. 24.36% were vaginal swab while 75.64% vagino/rectal. According to data collected at 31 centers with eligible data (22,175 pregnant GBS positivity was 12.7% (CI [Confidence Interval] + / -95%: 13.1% -12.2% with wide variability between individual centers (2% -22.6%. The enrichment broth is used by 6 out of 9 centers with positivity> 15% (M: 20.05%, from 6 to 14 with positivity between 10-15% (M: 12.61%, from none to 8 centers with less than 10% positivity (M: 4.95%.This multicentre survey underlined the preference for vagino/rectal swab, as recommended by the literature. The frequency of GBS positivity of pregnant women on the whole samples is similar to that found in other national surveys, even if with large differences between the different centers.The sensitivity tends to increase with the use of enrichment techniques, whose use is uneven between the centers, perhaps indicating the need for greater uniformity of protocols based on the results of microbiological analysis EBM (Evidence Based Medicine.

Erythromycine resistance in streptococcus pyogenes group a throat isolates in sukkur city

International Nuclear Information System (INIS)

Memon, B.

2007-01-01

To examine and evaluate the predominant and common etiologic agent(s) of pharyngitis in Sukkur city and to determine their current antibiotic susceptibility/resistance trends. Out of 257 throat samples, 149 positive for Streptococcus pyogenes Group A between November 2001 and May 2003 from adult population of Sukkur city were tested for their susceptibility to erythromycin, clindamycin, azithromycin and clairithromycin. The throat samples (swabs) were examined by Gram-stain, API system, and for presence of a hemolysis. Samples were further cultured on Muller Hinton agar for determination of antibiotic sensitivity patterns. The sensitivity was performed on only those samples which were positive for S. pyogenes. Of all throat isolates, 95% were predominantly resistant to erythromycin. Their sensitivity towards clindamycin was 30%, azithromycin 44% and clairithromycin 76% respectively. The current pharyngeal isolates of S. pyogenes exhibited frequent and alarmingly high erythromycin resistance which may be due to both intrinsic and acquired mechanisms. (author)

Epidemiology of Mycoplasma agalactiae and Mycoplasma mycoides cluster in flocks of northeastern Brazil

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Sandra Batista dos Santos

2018-04-01

Full Text Available ABSTRACT: The present study aimed to investigate contagious agalactia (CA in flocks from Pernambuco State. The study involved 225 goats and 63 ewes; 288 milk samples and 100 vaginal swabs were collected in total. The PCR assays were carried out using specific primers to Mycoplasma agalactiae and the Mycoplasma mycoides cluster. Among the goat’s milk samples,12.0% (27/225 were positive for Mycoplasma agalactiae DNA, while 5.3% (12/225 contained the Mycoplasma mycoides cluster. Of the vaginal swabs taken from goats, 15.4% (12/78 were positive for Mycoplasma agalactiae DNA and 3.8% (3/78 contained the Mycoplasma mycoides cluster. In the case of ewes, 4.3% (1/23 of the milk samples contained Mycoplasma agalactiae DNA, and 7.5% (3/40 were positive for the Mycoplasma mycoides cluster. Vaginal swabs taken from sheep´s were negative. Analysis of risk factors for mycoplasmosis, showed that goats and sheep flocks on the extensive breeding system are more likely to have mycoplasmosis than those on the intensive breeding system (odds ratio (OR 6.2; p=0.004; meat goat and sheep flocks are more likely to have infection compared to dairy flocks (OR 4.8; p=0.011; unclean animal housing increases the chances of infection (OR 5.0; p=0.031 and not performing quarantine increases the chances of mycoplasmosis (OR 4.6; p=0.042. Based on these findings we conclude that CA syndrome in the semiarid region of Pernambuco state can be associated with Mycoplasma agalactiae and Mycoplasma mycoides cluster.

Clonal structure of Streptococcus sanguinis strains isolated from endocarditis cases and the oral cavity.

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Do, T; Gilbert, S C; Klein, J; Warren, S; Wade, W G; Beighton, D

2011-10-01

A collection of Streptococcus sanguinis strains from patients with endocarditis (n = 21) and from the oral cavity (n = 34) was subjected to a multi-locus sequence typing analysis using seven housekeeping genes, carbamoyl-phosphate synthetase (carB), Co/Zn/Cd efflux system component (czcD), d-alanyl-d-alanine ligase (ddl), DNA polymerase III (dnaX), glucose-6-phosphate dehydrogenase (gdh), DNA-directed RNA polymerase, beta subunit (rpoB) and superoxide dismutase (sodA). The scheme was expanded by the inclusion of two the putative virulence genes, bacitracin-resistance protein (bacA) and saliva-binding protein (ssaB), to increase strain discrimination. Extensive intra-species recombination was apparent in all genes but inter-species recombination was also apparent with strains apparently harbouring gdh and ddl from unidentified sources and one isolate harboured a sodA allele apparently derived from Streptococcus oralis. The recombination/mutation ratio for the concatenated housekeeping gene sequences was 1.67 (95% confidence limits 1.25-2.72) and for the two virulence genes the r/m ratio was 3.99 (95% confidence limits 1.61-8.72); recombination was the major driver for genetic variation. All isolates were distinct and the endocarditis strains did not form distinct sub-clusters when the data were analysed using ClonalFrame. These data support the widely held opinion that infecting S. sanguinis strains are opportunistic human pathogens. © 2011 John Wiley & Sons A/S.

Prevalence and etiology of buffalo mastitis and milk somatic cell count in dry and rainy seasons in a buffalo herd from Analândia, São Paulo State, Brazil

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L.J.L. Pizauro

2014-12-01

Full Text Available The aim of this study was to evaluate somatic cell count (SCC, prevalence and etiology of mastitis in a dairy buffalo herd from Analândia, São Paulo State, Brazil, in the dry and rainy seasons. Additionally, antimicrobial susceptibility profile of microorganisms isolated from milk samples was also evaluated. 1,042 milk samples from female Murrah buffaloes in a dairy farm located in Analândia, São Paulo State, Brazil, collected between May 2011 and November 2012 were analyzed. After the mammary gland physical examination, strip cup test and California Mastitis Test (CMT were performed. Afterwards, 50mL of milk samples from each mammary quarter were collected aseptically for SCC in automatic equipment and microbiological examination. The antimicrobial sensitivity profile to ampicillin, cefoperazone, ceftiofur, enrofloxacin, gentamicin, neomycin, oxacillin, penicillin, and sulfamethoxazole/trimethoprim was evaluated by disk diffusion method. The monthly average temperature and pluviometric index were obtained from "Centro Integrado de Informações Agrometeorológicas" (CIIAGRO of "Instituto Agronômico de Campinas" (IAC. Milk samples with positive results in the microbiological test showed average SCC of 137,720 cells/mL in the dry period and 190,309 cells/mL in the rainy period. Although a higher number of isolated microorganisms was observed in buffalo milk samples during the rainy period (69/600 compared to the dry period (50/442, the season had no significant effect on the frequency of isolation of microorganisms. The main genera of microorganisms isolated were coagulase-negative Staphylococcus (38.4%, Streptococcus agalactiae (28.8%, and Bacillus spp. (7.56% during the dry season and Corynebacterium sp. (23.5%, Streptococcus spp. (32.3%, and Streptococcus agalactiae (9.24% during the rainy period. Multidrug resistance was observed in 30.1% of the isolated microorganisms.

Antibacterial Activity of Rhodomyrtus tomentosa (Aiton Hassk. Leaf Extract against Clinical Isolates of Streptococcus pyogenes

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Surasak Limsuwan

2012-01-01

Full Text Available Ethanol extract of Rhodomyrtus tomentosa (Aiton Hassk. leaf was evaluated for antibacterial activity against 47 clinical isolates of Streptococcus pyogenes. The extract exhibited good anti-S. pyogenes activity against all the tested isolates with similar minimum inhibitory concentration (MIC, 3.91–62.5 μg mL−1 and minimum bactericidal concentration (MBC, 3.91–62.5 μg mL−1 ranges. No surviving cells were detected at 16 h after treatment with 8 × MIC of the extract. The extract-treated cells demonstrated no lysis and cytoplasmic leakage through the bacterial membrane. Electron micrographs further revealed that the extract did not cause any dramatic changes on the treated cells. Rhodomyrtone, an isolated compound, exhibited good anti-S. pyogenes activity (14 isolates, expressed very low MIC (0.39–1.56 μg mL−1 and MBC (0.39-1.56 μg mL−1 values. Rhodomyrtus tomentosa leaf extract and rhodomyrtone displayed promising antibacterial activity against clinical isolates of S. pyogenes.

[Antibacterial activity of cefpodoxime against clinical isolates in 2000 and 2001].

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Abe, Tomomi; Fukuoka, Takashi; Sato, Yuki; Ito, Kazuyoshi; Sei, Masami

2002-12-01

As the post-marketing surveillance of cefpodoxime proxetil (Banan), MICs of cefpodoxime (CPDX, an active form of Banan) against 1090 clinical isolates of 22 species from 15 medical institutions all over Japan from June 2000 to March 2001 were measured using the broth microdilution method approved by the Japanese Society of Chemotherapy and compared with those of oral cephem antibacterials, cefaclor, cefdinir, cefditoren, and cefcapene. In this study, remarkable change in the activity of CPDX was observed in Streptococcus pneumoniae and Haemophilus influenzae compared with the susceptibility in the studies before Banan was launched. This cause is considered to be the increase in the incidence of the following resistant strains: penicillin-intermediate S. pneumoniae (47.3%), penicillin-resistant S. pneumoniae (PRSP, 15.1%), and beta-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae (24.0%), which were scarcely isolated in 1989 when Banan was launched. Other tested drugs also exhibited low activity against these resistant strains. However, CPDX showed comparatively good activity with MIC90 of 2 micrograms/mL against PRSP. Against methicillin-susceptible Staphylococcus spp., Streptococcus pyogenes, Streptococcus agalactiae, and Moraxella catarrhalis, CPDX also showed comparatively good activity with MIC90 of marketing. Against quinolones-resistant Neisseria gonorrhoeae, CPDX showed excellent activity with MIC90 of 0.5 microgram/mL. Against members of the family Enterobacteriaceae except for Citrobacter freundii, Enterobacter spp., Proteus vulgaris, and Morganella morganii, CPDX showed good activity. However, in Escherichia coli, Klebsiella spp. Proteus spp., and Providencia spp., there are some high-resistant strains to all tested drugs including CPDX. Against Peptostreptococcus spp., MIC90 of CPDX was 8 micrograms/mL and its MIC range was widely distributed from 0.03 to 32 micrograms/mL, which were similar to those in the studies before its marketing. In

Group B Streptococcus and the Vaginal Microbiota.

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Rosen, Geoffrey H; Randis, Tara M; Desai, Purnahamsi V; Sapra, Katherine J; Ma, Bing; Gajer, Pawel; Humphrys, Michael S; Ravel, Jacques; Gelber, Shari E; Ratner, Adam J

2017-09-15

Streptococcus agalactiae (group B Streptococcus [GBS]) is an important neonatal pathogen and emerging cause of disease in adults. The major risk factor for neonatal disease is maternal vaginal colonization. However, little is known about the relationship between GBS and vaginal microbiota. Vaginal lavage samples from nonpregnant women were tested for GBS, and amplicon-based sequencing targeting the 16S ribosomal RNA V3-V4 region was performed. Four hundred twenty-eight of 432 samples met the high-quality read threshold. There was no relationship between GBS carriage and demographic characteristics, α-diversity, or overall vaginal microbiota community state type (CST). Within the non-Lactobacillus-dominant CST IV, GBS positive status was significantly more prevalent in CST IV-A than CST IV-B. Significant clustering by GBS status was noted on principal coordinates analysis, and 18 individual taxa were found to be significantly associated with GBS carriage by linear discriminant analysis. After adjusting for race/ethnicity, 4 taxa were positively associated with GBS, and 6 were negatively associated. Vaginal microbiota CST and α-diversity are not related to GBS status. However, specific microbial taxa are associated with colonization of this important human pathogen, highlighting a potential role for the microbiota in promotion or inhibition of GBS colonization. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Efficacy of some synthetic antibiotics on Streptococcus pneumoniae ...

African Journals Online (AJOL)

Effects of some synthetic antibiotics on Streptococcus pnemoniae and Proteus mirabilis isolated from cultured Clarias gariepinus, an important food fish raised in a concrete tank was carried out to ascertain their remedies on mortalities of the Clarias gariepinus adult fish. Streptococcus pnemoniae and Proteus mirabilis were ...

Draft genome sequences of three virulent Streptococcus thermophilus bacteriophages isolated from the dairy environment in the Veneto region of Italy

DEFF Research Database (Denmark)

Duarte, Viní­cius da Silva; Giaretta, Sabrina; Treu, Laura

2018-01-01

Streptococcus thermophilus, a very important dairy species, is constantly threatened by phage infection. We report the genome sequences of three S. thermophilus bacteriophages isolated from a dairy environment in the Veneto region of Italy. These sequences will be used for the development of new ...

Quantitative susceptibility of Streptococcus suis strains isolated from diseased pigs in seven European countries to antimicrobial agents licenced in veterinary medicine

NARCIS (Netherlands)

Wisselink, H.J.; Veldman, K.T.; Salmon, S.A.; Mevius, D.J.

2006-01-01

The susceptibility of Streptococcus suis strains (n = 384) isolated from diseased pigs in seven European countries to 10 antimicrobial agents was determined. For that purpose a microbroth dilution method was used according to CLSI recommendations. The following antimicrobial agents were tested:

Comparative genomics of Streptococcus pyogenes M1 isolates differing in virulence and propensity to cause systemic infection in mice

NARCIS (Netherlands)

Fiebig, A.; Loof, T.G.; Babbar, A.; Itzeg, A.; Koehorst, J.J.; Schaap, P.J.; Nitsche-Schmitz, D.P.

2015-01-01

Streptococcus pyogenes serotype M1 is a frequent cause of severe infections in humans. Some M1 isolates are pathogenic in mice and used in studies on infection pathogenesis. We observed marked differences in murine infections caused by M1 strain SF370, 5448, 5448AP or AP1 which prompted us to

Pathogenesis of Streptococcus infantarius subspecies coli Isolated from Sea Otters with Infective Endocarditis.

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Counihan, Katrina L; Gill, Verena A; Miller, Melissa A; Burek-Huntington, Kathleen A; LeFebvre, Rance B; Byrne, Barbara A

2015-06-01

The Gram positive bacterial coccus Streptococcus infantarius subspecies coli is increasingly linked with development of fatal vegetative infective endocarditis and septicemia in humans, sea otters (Enhydra lutris) and other animals. However, the pathogenesis of these infections is poorly understood. Using S. infantarius subsp. coli strains isolated from sea otters with infective endocarditis, this study evaluated adherence and invasion of epithelial and endothelial cells, adherence to extracellular matrix components, and macrophage survival. Significant adherence to endothelial-derived cells was observed for 62% of isolates, 24% adhered to epithelial cell lines, and 95% invaded one or both cell types in vitro. The importance of the hyaluronic acid capsule in host cell adherence and invasion was also evaluated. Capsule removal significantly reduced epithelial adherence and invasion for most S. infantarius subsp. coli isolates, suggesting that the capsule facilitates attachment to and invasion of epithelium. Enzyme-linked immunosorbent assay testing revealed that all isolates adhered significantly to the extracellular matrix components collagen IV, fibronectin, laminin and hyaluronic acid. Finally, significant bacterial survival following phagocytosis by macrophages was apparent for 81% of isolates at one or more time points. Taken collectively these findings indicate that S. infantarius subsp. coli has multiple pathogenic properties that may be important to host colonization, invasion and disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of the Lactococcal nisA Promoter To Regulate Gene Expression in Gram-Positive Bacteria : Comparison of Induction Level and Promoter Strength

NARCIS (Netherlands)

Eichenbaum, Zehava; Federle, Michael J.; Marra, Diana; Vos, Willem M. de; Kuipers, Oscar P.; Kleerebezem, Michiel; Scott, June R.

1998-01-01

We characterized the regulated activity of the lactococcal nisA promoter in strains of the gram-positive species Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Enterococcus faecalis, and Bacillus subtilis. nisA promoter activity was dependent on the proteins NisR and

Epidemiological relationship of human and swine Streptococcus suis isolates.

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Tarradas, C; Luque, I; de Andrés, D; Abdel-Aziz Shahein, Y E; Pons, P; González, F; Borge, C; Perea, A

2001-06-01

Two cases of meningitis due to Streptococcus suis in humans are reported here. A butcher and an abattoir worker were referred to a health centre in Castellón (Spain) with fever and symptoms of meningitis. After adequate treatment, a slight hipoacusia persisted as sequelae in both cases. Colonies of S. suis group R, serotype 2 and phenotype MRP+EF+ were isolated from cerebroespinal fluid. Epidemiological studies showed that both workers had in common the handling of pork meat of slaughtered healthy pigs from three closed farms. A study of the tonsils from apparently healthy, slaughtered pigs was carried out. A total of 234 tonsillar samples were obtained and 81 strains of S. suis were isolated from them. Serotype 2 appeared to be the most frequent (50.6%), and the analysis for phenotype showed a high percentage of tonsillar strains with the phenotype MRP+EF+ (35.9%). The humans and 28 tonsillar swine strains showed a similar profile (S. suis group R, serotype 2 and phenotype MRP+EF+). A total of 26 of the swine isolates were analysed by ribotyping using EcoRI. The human strains showed the same six-band hybridization pattern that shared five bands with the pattern most frequently shown by most of the tonsillar N. suis group R, serotype 2 and phenotype MRP+EF+ strains, differing only in the lightest, faintest band which was slightly less anodical in human (> or = 1.8 kb) than in swine (approximately 1.8 kb). From these results, both groups of strains, humans and porcine, showed differences; how can these differences in the pattern of ribotyping be explained if they should have the same origin? Is it possible that they have undergone an adaptation to the new host or perhaps the modification is due to other unknown causes? Further studies in this area are required in order to answer these questions.

[THE DIAGNOSTIC APPROACHES TO VERIFICATION OF STREPTOCOCCUS INFECTION IN PATIENTS WITH INFECTIOUS MONONUCLEOSIS].

Science.gov (United States)

Kim, M A; Labushkina, A V; Simovanian, E N; Kharseeva, G G

2015-11-01

The Rostovskii state medical university of Minzdrav of Russia, 344022 Rostov-on-Don, Russia The analysis is applied concerning significance of laboratory techniques of verification of streptococcus infection (bacteriological analysis, detection of anti-streptolysin O in pair serums) in 148 patients with infectious mononucleosis aged from 3 to 15 years. The content of anti-streptolysin O exceeded standard in 41 ± 4.8% of patients with concomitant in acute period and in 49.5 ± 4.9% during period of re-convalescence. This data differed from analogous indicator in patients with negative result of examination on streptococcus infection independently of period of disease (9.3 ± 2.8%). The exceeding of standard of anti-streptolysin O was detected more frequently (t ≥ 2, P ≥ 95%) in patients with isolation of Streptococcus pyogenes (56.9 ± 5.8%) than in patients with Streptococcus viridans (31.2 ± 6.5%). The concentration of anti-streptolysin 0 in patients with concomitant streptococcus infection varied within limits 200-1800 IE/ml. The minimal level of anti-streptolysin O (C = 200 IE/mI) was detected independently of type of isolated Streptococcus and period of disease. The high levels of anti-streptolysin O were observed exclusively in patients with isolation of Streptococcus pyogenes. In blood serum ofpatient with concomitant streptococcus infection (Streptococcus pyogenes + Streptococcus viridans) increasing of level of anti-streptolysin O was detected in dynamics of diseases from minimal (C = 200 IE/ ml) to moderately high (200 mononucleosis the anamnesis data is to be considered. The complex bacteriological and serological examination ofpatients is to be implemented This is necessary for early detection ofpatients with streptococcus infection and decreasing risk of formation of streptococcus carrier state.

[Yearly changes in antibacterial activities of cefozopran against various clinical isolates between 1996 and 2000--I. Gram-positive bacteria].

Science.gov (United States)

Suzuki, Yumiko; Nishinari, Chisato; Endo, Harumi; Tamura, Chieko; Jinbo, Keiko; Hiramatsu, Nobuyoshi; Akiyama, Kazumitsu; Koyama, Tsuneo

2002-04-01

The in vitro antibacterial activities of cefozopran (CZOP), an agent of cephems, against various clinical isolates obtained between 1996 and 2000 were yearly evaluated and compared with those of other cephems, oxacephems, carbapenems, and penicillins. Fifteen species, 1,062 strains, of Gram-positive bacteria were isolated from the clinical materials annually collected from January to December, and consisted of methicillin-susceptible Staphylococcus aureus (MSSA; n = 127), methicillin-resistant Staphylococcus aureus (MRSA; n = 123), Staphylococcus epidermidis (n = 104), Staphylococcus haemolyticus (n = 58), Streptococcus pyogenes (n = 100), Streptococcus agalactiae (n = 50), Streptococcus pneumoniae (n = 125), Enterococcus faecalis (n = 150), Enterococcus faecium (n = 50), Enterococcus avium (n = 50), and Peptostreptococcus spp. (P. anaerobius, P. asaccharolyticus, P. magnus, P. micros, P. prevotii; n = 125). CZOP possessed stable antibacterial activities against all strains tested throughout 5 years. The MIC90 of CZOP against MRSA and S. haemolyticus tended to decrease while against S. pneumoniae and Peptostreptococcus spp., tended to increase year by year. However, the MIC90 just changed a little and were consistent with the results from the studies performed until the new drug application approval. Increases in the MIC90 against S. pneumoniae were also observed with cefpirome (CPR), cefepime (CFPM), flomoxef (FMOX), sulbactam/cefoperazone (SBT/CPZ), and imipenem (IPM). Increases in the MIC90 against Peptostreptococcus spp. were also observed with ceftazidime (CAZ), CPR, CFPM, FMOX, SBT/CPZ, and IPM. The decreases in the sensitivities were not always considered to depend upon generation of resistant bacteria because the annual MIC range of each antibacterial agent was almost generally wide every year and the annual sensitivity of each strain to the agents extremely varied. In conclusion, the annual antibacterial activities of CZOP against the Gram

Chemical composition and antimicrobial activity of berry essential oil of Juniperus oxycedrus L. (Cupressaceae grown wild in Republic of Macedonia

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Floresha Sela

2013-06-01

Full Text Available Chemical composition and antimicrobial activity of essential oil isolated from berries from 2 different samples of Juniperus oxycedrus L. (Cupressaceae, growing wild in Republic of Macedonia was investigated. Performing GC/FID/MS analysis, one hundred components were identified, representing 96.0-98.95% of the oil. The major components were α-pinene (22.54- 27.12%, myrcene (11.26- 15.13% and limonene (2.78-18.06%. Antimicrobial screening of the J. oxycedrus essential oils was made by disc diffusion and broth dilution method against 16 bacterial isolates of Gram positive and Gram negative bacteria and one strain of Candida albicans. The most sensitive bacteria was Haemophilus influenzae (MIC = 125 ml/ml. The essential oils showed moderate antimicrobial activity against Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Corynebacterium spp., Escherichia coli and Campilobacter jejuni (MIC > 500 ml/ml and no activity against Candida albicans, Staphylococcus epidermidis, Acinetobacter spp., Salmonella enteritidis, Shigella flexnery, Klebsiella pneumonia, Pseudomonas aeruginosa, Enterococcus and Proteus mirabilis.

Diversity of seM in Streptococcus equi subsp. equi isolated from strangles outbreaks.

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Libardoni, Felipe; Vielmo, Andréia; Farias, Luana; Matter, Letícia Beatriz; Pötter, Luciana; Spilki, Fernando Rosado; de Vargas, Agueda Castagna

2013-03-23

Strangles is the main upper respiratory tract disease of horses. There are currently no studies on the changes in alleles of the M protein gene (seM) in Brazilian isolates of Streptococcus equi ssp. equi (S. equi). This study aimed to analyze and differentiate molecularly S. equi isolates from equine clinical specimens from southern Brazil, between 1994 and 2010. seM alleles were analyzed in 47 isolates of S. equi obtained from clinical cases of strangles (15 Thoroughbred horses, 29 Crioulo breed horses and three Brasileiro de Hipismo--BH). seM alleles characterization was performed by comparing variable region sequences of the seM gene. The alleles were also phylogenetically grouped by Neighbor-joining analysis, which demonstrated the geographic distribution of those in properties from southern Brazil. Fifteen alleles of the gene seM were found among the 47 S. equi isolates analyzed. Among these, only one allele (seM-61), which was identified in seven isolates (14.9%), was found in the database PubMLST-seM. Within the new alleles, allele seM-115 was the most prevalent, having been found in 13 isolates (27.7%), followed by allele seM-117 in 10 isolates (21.3%). In the Brazilian horse population studied, there is greater diversity of M protein alleles in S. equi isolates compared to worldwide data deposited in PubMLST-seM. Among the 15 seM alleles identified, only one allele sequence was previously published. The alleles identification is important to control the disease by guiding selection of strains for the manufacture of commercial and autogenous vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

Group B Streptococcus Induces Neutrophil Recruitment to Gestational Tissues and Elaboration of Extracellular Traps and Nutritional Immunity

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Kothary, Vishesh; Doster, Ryan S.; Rogers, Lisa M.; Kirk, Leslie A.; Boyd, Kelli L.; Romano-Keeler, Joann; Haley, Kathryn P.; Manning, Shannon D.; Aronoff, David M.; Gaddy, Jennifer A.

2017-01-01

Streptococcus agalactiae, or Group B Streptococcus (GBS), is a gram-positive bacterial pathogen associated with infection during pregnancy and is a major cause of morbidity and mortality in neonates. Infection of the extraplacental membranes surrounding the developing fetus, a condition known as chorioamnionitis, is characterized histopathologically by profound infiltration of polymorphonuclear cells (PMNs, neutrophils) and greatly increases the risk for preterm labor, stillbirth, or neonatal GBS infection. The advent of animal models of chorioamnionitis provides a powerful tool to study host-pathogen relationships in vivo and ex vivo. The purpose of this study was to evaluate the innate immune response elicited by GBS and evaluate how antimicrobial strategies elaborated by these innate immune cells affect bacteria. Our work using a mouse model of GBS ascending vaginal infection during pregnancy reveals that clinically isolated GBS has the capacity to invade reproductive tissues and elicit host immune responses including infiltration of PMNs within the choriodecidua and placenta during infection, mirroring the human condition. Upon interacting with GBS, murine neutrophils elaborate DNA-containing extracellular traps, which immobilize GBS and are studded with antimicrobial molecules including lactoferrin. Exposure of GBS to holo- or apo-forms of lactoferrin reveals that the iron-sequestration activity of lactoferrin represses GBS growth and viability in a dose-dependent manner. Together, these data indicate that the mouse model of ascending infection is a useful tool to recapitulate human models of GBS infection during pregnancy. Furthermore, this work reveals that neutrophil extracellular traps ensnare GBS and repress bacterial growth via deposition of antimicrobial molecules, which drive nutritional immunity via metal sequestration strategies. PMID:28217556

A Highly Arginolytic Streptococcus Species That Potently Antagonizes Streptococcus mutans.

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Huang, Xuelian; Palmer, Sara R; Ahn, Sang-Joon; Richards, Vincent P; Williams, Matthew L; Nascimento, Marcelle M; Burne, Robert A

2016-01-29

The ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novel Streptococcus strain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogen Streptococcus mutans. A12 produced copious amounts of H2O2 via the pyruvate oxidase enzyme that were sufficient to arrest the growth of S. mutans. A12 also produced a protease similar to challisin (Sgc) of Streptococcus gordonii that was able to block the competence-stimulating peptide (CSP)-ComDE signaling system, which is essential for bacteriocin production by S. mutans. Wild-type A12, but not an sgc mutant derivative, could protect the sensitive indicator strain Streptococcus sanguinis SK150 from killing by the bacteriocins of S. mutans. A12, but not S. gordonii, could also block the XIP (comX-inducing peptide) signaling pathway, which is the proximal regulator of genetic competence in S. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar to Streptococcus australis and Streptococcus parasanguinis but sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

In Vitro Antimicrobial Activity of Plant-Derived Diterpenes against Bovine Mastitis Bacteria

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Rodrigo C. S. Veneziani

2013-07-01

Full Text Available We evaluated the antibacterial activity of three diterpenes isolated from natural sources against a panel of microorganisms responsible for bovine mastitis. ent-Copalic acid (CA was the most active metabolite, with promising MIC values (from 1.56 to 6.25 µg mL−1 against Staphylococcus aureus (ATCC and clinical isolate, Staphylococcus epidermidis, Streptococcus agalactiae, and Streptococcus dysgalactiae. We conducted time-kill assays of CA against S. aureus, a commensal organism considered to be a ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. In the first 12 h, CA only inhibited the growth of the inoculums (bacteriostatic effect, but its bactericidal effect was clearly noted thereafter (between 12 and 24 h. In conclusion, CA should be considered for the control of several Gram-positive bacteria related to bovine mastitis.

Влияние суппозиториев вагинальных на гемостаз железа на фоне экспериментального вагинита, отягощенного Escherichia coli

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Dolzhykova, O. V.; Maloshtan, L. M.; Yeriomenko, R. F.

2017-01-01

Currently, disorders of the vaginal flora are observed in 38 % of women, 11 % of them have aerobic vaginitis. Streptococcus agalactiae and Escherichia coli, which capture iron of the human body during bacterial infections, are isolated most frequently in cases of vaginitis.Aim. To study the effect of vaginal pessaries “Klimedeks” and “Melanizol” on iron hemostasis in female rats against the experimental positive Escherichia coli vaginitis.Materials and methods. The experiment was conducted on...

Avaliação da sensibilidade da cultura de leite do tanque para isolamento de agentes contagiosos da mastite bovina Evaluation of the sensitivity of bulk tank milk cultures for the isolation of contagious bovine mastitis pathogens

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Maria Aparecida V. P. Brito

1998-01-01

Full Text Available Amostras de leite total (leite do tanque de 33 rebanhos foram coletadas na plataforma de recepção da indústria laticinista e cultivadas para detectar patógenos específicos (contagiosos da mastite. Foi feita a contagem de células somáticas (CCS das amostras utilizando o equipamento Fossomatic 90. Em 13 e 12 rebanhos avaliaram-se duas e três amostras semanais consecutivas, respectivamente, e em oito avaliou-se apenas uma. Foram também examinadas três amostras diárias consecutivas do leite do tanque e amostras dos quartos mamários individuais, coletadas na própria fazenda, de todas as vacas em lactação de quatro rebanhos (A, B, C e D. As amostras de leite dos quartos mamários individuais foram cultivadas em ágar sangue e as amostras do tanque, em placas de TKT, Sal Manitol, MacConkey e Sabouraud contendo cloranfenicol. Dos 33 rebanhos cujas amostras foram obtidas na plataforma de recepção da indústria, isolou-se Staphylococcus aureus de 26, nove desses em associação com Streptococcus agalactiae e em três rebanhos isolou-se somente S. agalactiae. Nove rebanhos tiveram CCS acima de 500.000 ml-1 e 21, abaixo de 400.000 ml-1. Em cinco dos nove rebanhos com CCS acima de 500.000 ml-1 foram isolados S. aureus e S. agalactiae, em três, apenas S. aureus e em um, apenas S. agalactiae. Seis rebanhos apresentaram CCS abaixo de 200.000 ml-1; de um deles foram isolados S. aureus e S. agalactiae, de três, S. aureus e os outros dois foram negativos para estes dois patógenos. Os resultados encontrados nos quatro rebanhos cujas amostras foram coletadas na própria fazenda mostraram que S. aureus foi isolado nas seguintes porcentagens dos animais: 1,8%, 19,2%, 17,0% e 8,4% e dos quartos mamários: 0,9%, 5,9%, 5,4% e 2,2%, respectivamente, para os rebanhos A, B, C e D. S. agalactiae foi isolado dos rebanhos A, C e D. Nestes três rebanhos, as porcentagens de isolamento foram, respectivamente, 1,8%, 10,6% e 8,4% para as vacas e 0,46%, 3,8% e 3

Streptococcus pneumoniae Drugs Resistance in Acute Rhinosinusitis

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Chong Jie Hao

2016-03-01

Full Text Available Background: Acute rhinosinusitis that usually caused by Streptococcus pneumoniae becomes the reason why patients seek for medical care. Drugs resistance in Streptococcus pneumoniae is increasing worldwide. This study was conducted to determine drugs resistance of Streptococcus pneumonia from acute rhinosinusitis in Dr. Hasan Sadikin General Hospital. Methods: A descriptive laboratory study was conducted in June–October 2014 at the Laboratory of Microbiology Faculty of Medicine Universitas Padjadjaran. The sample was taken using nasopharyngeal swabbing from 100 acute rhinosinusitis patients in Dr. Hasan Sadikin General Hospital and planted on tryptic soy agar containing 5% sheep blood and 5 μg/ml of gentamicin sulphate and then incubated in 5% CO2 incubator at 37°C for 24 hours. The identification of Streptococcus pneumonia was performed by optochin test. The susceptibility test against Streptococcus pneumoniae was done using disk diffusion method.The antibiotic disks were trimethoprim-sulfamethoxazole, oxacillin, levofloxacin, azithromycin, and doxycycline. Results: Out of 100 samples, 8 of them were tested positive for Streptococcus pneumoniae. Three of Streptococcus pneumoniae isolates died with unknown reason after it were stored at -80 .The drugs resistance test showed the resistance of Streptococcus pneumonia to oxacillin, azithromycin and trimethoprim were 6, whereas levofloxacin and doxycycline are 4. Conclusions: Streptococcus pneumonia drugs resistance in acute rhinosinusitis shows the resistance of Streptococcus pneumoniae to oxacillin, azithromycin and trimethoprim are 6, whereas the resistance to levofloxacin and doxycycline are 4.

In silico assessment of virulence factors in strains of Streptococcus oralis and Streptococcus mitis isolated from patients with Infective Endocarditis

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Rasmussen, Louise H.; Iversen, Katrine Højholt; Dargis, Rimtas

2017-01-01

Streptococcus oralis and Streptococcus mitis belong to the Mitis group, which are mostly commensals in the human oral cavity. Even though S. oralis and S. mitis are oral commensals, they can be opportunistic pathogens causing infective endocarditis. A recent taxonomic re-evaluation of the Mitis...

Assessment and characterization of biofilm formation among human isolates of Streptococcus dysgalactiae subsp. equisimilis.

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Genteluci, Gabrielle Limeira; Silva, Ligia Guedes; Souza, Maria Clara; Glatthardt, Thaís; de Mattos, Marcos Corrêa; Ejzemberg, Regina; Alviano, Celuta Sales; Figueiredo, Agnes Marie Sá; Ferreira-Carvalho, Bernadete Teixeira

2015-12-01

The capacity to form biofilm is considered a protective mechanism that allows the bacteria to survive and proliferate in hostile environments, facilitating the maintenance of the infectious process. Recently, biofilm has become a topic of interest in the study of the human pathogen group A Streptococcus (GAS). Although GAS has not been associated with infection on medical implants, the presence of microcolonies embedded in an extracellular matrix on infected tissues has been reported. Despite the similarity between GAS and Streptococcus dysgalactiae subspecies equisimilis (SDSE), there are no studies in the literature describing the production of biofilm by SDSE. In this work, we assessed and characterized biofilm development among SDSE human isolates of group C. The in vitro data showed that 59.3% of the 118 isolates tested were able to form acid-induced biofilm on glass, and 28% formed it on polystyrene surfaces. More importantly, biofilm was also formed in a foreign body model in mice. The biofilm structure was analyzed by confocal laser scanning microscopy, transmission electron microscopy, and scanning electron microscopy. Long fibrillar-like structures were observed by scanning electron microscopy. Additionally, the expression of a pilus associated gene of SDSE was increased for in vitro sessile cells compared with planktonics, and when sessile cells were collected from biofilms formed in the animal model compared with that of in vitro model. Results obtained from the immunofluorescence microscopy indicated the biofilm was immunogenic. Our data also suggested a role for proteins, exopolysaccharide and extracellular DNA in the formation and accumulation of biofilm by SDSE. Copyright © 2015 Elsevier GmbH. All rights reserved.