scholarly journals LambdaSa1 and LambdaSa2 Prophage Lysins of Streptococcus agalactiae

2007 ◽  
Vol 73 (22) ◽  
pp. 7150-7154 ◽  
Author(s):  
David G. Pritchard ◽  
Shengli Dong ◽  
Marion C. Kirk ◽  
Robert T. Cartee ◽  
John R. Baker
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Streptococcus Agalactiae ◽  
Synthetic Peptide ◽  
Cell Walls ◽  
Peptide Substrate ◽  
Amidase Activity ◽  
Cleavage Specificity ◽  
Endopeptidase Activity

ABSTRACT Putative N-acetylmuramyl-l-alanine amidase genes from LambdaSa1 and LambdaSa2 prophages of Streptococcus agalactiae were cloned and expressed in Escherichia coli. The purified enzymes lysed the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae, and Staphylococcus aureus. The peptidoglycan digestion products in the cell wall lysates were not consistent with amidase activity. Instead, the structure of the muropeptide digestion fragments indicated that both the LambdaSa1 and LambdaSa2 lysins exhibited γ-d-glutaminyl-l-lysine endopeptidase activity. The endopeptidase cleavage specificity of the lysins was confirmed using a synthetic peptide substrate corresponding to a portion of the stem peptide and cross bridge of Streptococcus agalactiae peptidoglycan. The LambdaSa2 lysin also displayed β-d-N-acetylglucosaminidase activity.

Endotoxin-Like Activities of Mycoplasmal Lipopolysaccharides (Lipoglycans)

1980 ◽  
Vol 29 (3) ◽  
pp. 990-994
Author(s):  
Robert C. Seid ◽  
Paul F. Smith ◽  
Gabriel Guevarra ◽  
H. Donald Hochstein ◽  
Michael F. Barile
Keyword(s):  
Escherichia Coli ◽  
Synthetic Peptide ◽  
Active Role ◽  
Peptide Bond ◽  
Febrile Response ◽  
Thermoplasma Acidophilum ◽  
Amidase Activity ◽  
E Coli

Lipoglycans (previously designated lipopolysaccharides) from several species of Acholeplasma and from Thermoplasma acidophilum were examined for endotoxin-like activities as measured by the standard rabbit fever test and the Limulus amoebocyte lysate assay. The lipoglycans from Acholeplasma granularum, Achloplasma laidlawii, Acholeplasma modicum , and Acholeplasma oculi caused a febrile response at concentrations of 1 ng/ml per kg or greater, whereas with control Escherichia coli EC-2 lipopolysaccharides, 6.25 ng/ml per kg was required. Similar results were obtained in the Limulus amoebocyte lysate test. The minimum concentrations in nanograms per milliliter required to stimulate formation of a solid clot were: Acholeplasma axanthum , 0.22; A. granularum , 0.85; A. modicum , 0.51; A. laidlawii , 1.05; A. oculi , 0.74. Standard E. coli 1B lipopolysaccharide required a concentration of 0.125 ng/ml. Thermoplasma lipoglycan was least active, requiring 4.25 ng/ml. Clotting of the Limulus lysate proceeds by the activation by lipopolysaccharide plus Ca 2+ of a proenzyme which cleaves an arginine-lysine peptide bond of the coagulogen. The clotting and amidase activities are inactivated by deoxycholate and can be reactivated by addition of lipopolysaccharide and Ca 2+ . As with E. coli 1B lipopolysaccharide, acholeplasmal lipoglycans were shown to restore both clotting and amidase activities of the deoxycholate-inactivated Limulus clotting enzyme. The degree of restoration of amidase activity by mycoplasmal lipoglycans relative to E. coli lipopolysaccharide (1.00) were: A. axanthum , 1.71; A. modicum , 1.22; A. granularum , 0.61; and Thermoplasma , 0.37. The coagulating enzyme, restored with either E. coli lipopolysaccharide or mycoplasmal lipoglycans, was able to react with the synthetic peptide benzoyl-Ile-Glu-(γ-OCH 3 )-Gly-p-nitroaniline (an analog of the coagulogen) or with the purified coagulogen itself to form the clot. The mycoplasmal lipoglycans alone were incapable of promoting these reactions when incubated with the synthetic peptide or with the purified coagulogen, thereby ruling out the contamination of these lipoglycans with proteases capable of cleaving the same Arg-Lys peptide bond of the coagulogen. These results show that acholeplasmal lipoglycans possess endotoxin-like activities. Their passive or active role in disease remains to be established.

scholarly journals Possibility of application of dodicin hydrochloride in prevention of mastitis in cows

2006 ◽  
Vol 60 (3-4) ◽  
pp. 207-221
Author(s):  
Svetlana Joksovic ◽  
Vitomir Cupic ◽  
Vera Katic
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Streptococcus Agalactiae ◽  
Control Group ◽  
Main Approach ◽  
Laboratory Conditions ◽  
Streptococcus Uberis ◽  
Holstein Friesian ◽  
Experimental Group ◽  
Outer Environment

The main approach to curbing mastitis is to prevent the entry of microorganisms from the outer environment into the mammary gland, which is achieved by the use of papilla disinfection following every time of milking. The objective of this work was to examine the antimicrobial activity of the disinfectant dodicin hydrochloride, in fact the preparation that contains this disinfectant (DESU? M), against bacteria, the most frequent causes of mastitis in cows. The efficacy of modified DESU? Mwas examined under laboratory conditions using the quantitative test against the following microorganisms: Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae and Streptococcus uberis, under the conditions in the field. The udders of an experimental group of 20 cows of the Holstein-Friesian breed were immersed in a solution of the modified preparation DESU ? M following every time of milking over a period of three months. In the second group of 10 cows of the Holstein-Friesian breed, marked as the control group, no disinfection was applied following the milkings. The preparation DESU? Mexhibited satisfactory antimicrobial efficacy against the most frequent causes (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae and Streptococcus uberis) of mastitis in cows under laboratory conditions. With the application of the preparation DESU? M, following every time of milking over a period of three months, the number of somatic cells was reduced by almost one half in comparison with their number at the start of the experiment. No residue of the modified preparation DESU ? M were found in any sample of milk from the experimental group of cows.

Absence of Bacterial Adherence in the Establishment of Experimental Mastitis in Mice

1978 ◽  
Vol 15 (6) ◽  
pp. 770-775 ◽  
Author(s):  
J. C. Anderson
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Mammary Gland ◽  
Significant Role ◽  
Streptococcus Agalactiae ◽  
Staphylococcus Epidermidis ◽  
Alveolar Epithelium ◽  
Bacterial Adherence ◽  
E Coli ◽  
Suckling Mice

The possibility of adherence of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli or Streptococcus agalactiae to the epithelium of the mammary gland was investigated by inoculating them into this gland of mice. S. aureus, S. epidermidis and E. coli did not adhere to alveolar epithelium in suckling or non-suckling mice. S. agalactiae adhered to alveolar epithelium in non-suckling mice but adhesion was not sufficiently strong to withstand suckling. Bacterial adherence probably does not play a significant role in the establishment of mastitis by these organisms.

scholarly journals Izolacija bakterijskih patogena kod klinički manifestnih mastitisa mliječnih goveda i njihova antimikrobna osjetljivost u zeničkoj regiji u 2017. godini

2020 ◽  
Vol 51 (1) ◽  
pp. 47-52
Author(s):  
Jasmin Burović
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Yersinia Enterocolitica ◽  
Streptococcus Agalactiae ◽  
Enterococcus Spp

Ova studija predstavlja podatke prikupljene iz Veterinarske stanice “Zevet” d.o.o. Zenica, Bosna i Hercegovina o zastupljenosti bakterijskih patogena kod klinički prisutnih mastitisa mliječnih goveda i profilima njihove antimikrobne osjetljivosti. Za laboratorijsku izolaciju obrađena su 52 uzorka od kojih su 23 bila bakteriološki pozitivna. Najčešći izolati bili su Staphylococcus aureus u 21,74 % uzoraka i Streptococcus agalactiae u 17,39 % izolira- nih uzoraka, koagulaza-negativni stafilokoki (13,04 %), Klebsiella pneumoniae (13,04 %), Ente- rococcus spp. (8,70 %), Escherichia coli (8,70 %), Streptococcus spp., Enterobacter, Serratia spp. i Yersinia enterocolitica (4,35 %). Najveća antimikrobna otpornost među izolatima primjećena je na benzilpenicilin (56,25 %) i oksitetraciklin (46,15 %) s ukupnom otpornosti na uporabljena antimikrobna sredstava od 25,99 %. Na tri testirana antimikrobna sredstva (neomicin, klindamicin i cefotaksim) izolati nisu pokazali otpornost. Ostali antibiotici na koje je primijećena niska ukupna otpornost su ciprofloksacin (5,56 %) i ofloksacin (6,67 %). Samo jedan izolat nije pokazao nikakvu otpornost na testirane antimikrobike (S. aureus). Najveću otpornost među izolatima pokazao je Enterococcus spp., pokazujući senzibilitet samo za tetracikline. S. aureus je pokazao otpornost na benzilpenicilin i cefaleksin u 60 % slučajeva. Svi izolati S. agalactiae su bili otporni na tetracikline, oksitetracikline i gentamicin. Koagulaza negativni stafilokoki pokazali su otpornost na cefaleksin u dva slučaja i otpornost na benzilpenicilin, eri- tromicin i oksacilin u jednom izolatu. Klebsiella pneumoniae je pokazala otpornost na cefaleksin, amoksicilin i benzilpenicilin u svim ispitivanim izolatima, a pokazala je i otpornost na tetracikline u dva izolata. Svi ostali izolati pokazali su otpornost prema najmanje jednom testiranom antimikrobiku. U 46 slučajeva se odmah pristu- palo liječenju s 86,96 % uspjehom koji je procijenjen na osnovu izostanka kliničkog relapsa i smanjenja broja somatskih stanica u dopuštene granice za tri tjedna nakon provedene terapije.

scholarly journals Prevalência e perfil de sensibilidade a antimicrobianos de uropatógenos em pacientes atendidos no laboratório escola do Centro Universitário de Brasília (UniCEUB) - Distrito Federal

2021 ◽  
Author(s):  
Bárbara Clemente Ribeiro ◽  
Hian Delfino Ferreira Da Silva ◽  
Luís Eduardo Santos Barros
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Klebsiella Pneumoniae ◽  
Enterococcus Faecalis ◽  
Proteus Mirabilis ◽  
Streptococcus Agalactiae ◽  
Staphylococcus Saprophyticus ◽  
Staphylococcus Haemolyticus ◽  
E 52 ◽  
Distrito Federal

O uso indiscriminado de antibióticos no tratamento das Infecções do Trato Urinário (ITU) funciona como pressão seletiva ao surgimento de resistência bacteriana aos antimicrobianos. Deste modo, este estudo teve como objetivo determinar a prevalência de uroculturas positivas e o perfil antimicrobiano dos organismos encontrados em pacientes ambulatoriais atendidos no Laboratório Escola no Centro Universitário de Brasília (UniCEUB) no Distrito Federal. Foi realizado um estudo transversal retrospectivo, no qual teve como base a análise dos registros laboratoriais de uroculturas realizadas no período entre Agosto de 2017 e Dezembro de 2019. Os selecionados como critérios de inclusão: apresentar crescimento microbiano igual ou superior a 100.000 UFC/mL (Unidades Formadoras de Colônia) na urina, possuir resultado de identificação do agente patogênico e o resultado do teste de sensibilidade aos antimicrobianos. Foram excluídos da pesquisa pacientes com os dados cadastrais incompletos. Durante o período analisado, foram realizados 2.436 exames de urocultura, destes 2.281 foram excluídos do estudo: 2.252 por não apresentarem crescimento bacteriano e 29 não apresentaram ficha cadastral completa ou crescimento microbiano inferior ao selecionado para a pesquisa. Por fim, foram selecionadas para este trabalho 155 uroculturas positivas, dentre as quais 92% (142) pertenciam a pacientes do sexofemino e 8% (13) ao sexo masculino, com idade média de 48 e 52 anos respectivamente. Dentre a população analisada, foi observado positividade das uroculturas para os seguintes microrganismos: Escherichia coli (78,71%), Klebsiella pneumoniae (7,74%), Proteus mirabilis (4,52%), Streptococcus agalactiae (3,87%), Staphylococcus saprophyticus (1,94%), Staphylococcus haemolyticus e Enterococcus faecalis (1,29%) e Staphylococcus aureus (0,65%). A Escherichia coli foi o microrganismo que apresentou maior prevalência dentre as uroculturas analisadas, de modo que foi avaliado também o perfil de sensibilidade aos antimicrobianos para tal patógeno. Com exceção da ampicilina e da cefalotina, todos os β-lactâmicos testados apresentaram sensibilidade superior a 80%. A resistência da Escherichia coli a ampicilina foi de 50,82%, enquanto a resistência média aos cefalosporínicos foi de aproximadamente 11,5%, 5,74% a gentamicina. Os derivados quinolônicos apresentaram as maiores taxas de resistência: entre 24,59% e 40,98%. Ao utilizar a associação Trimetoprim e Sulfametoxazol, foi observado 29,51% de resistência. Nas amostras analisadas, não houve resistência aos carbapenêmicos. Com base nos dados avaliados, conclui-se que a Escherichiacoli permanece como o principal microrganismo causador de ITU’s em pacientes ambulatoriais. Com base nisto se faz necessário o planejamento de um esquema terapêutico eficaz, visto que o microrganismo apresenta algum grau de resistência a diversos antimicrobianos utilizados na prática clínica.

scholarly journals Staphylococcus aureus cell wall structure and dynamics during host-pathogen interaction

2021 ◽  
Vol 17 (3) ◽  
pp. e1009468
Author(s):  
Joshua A. F. Sutton ◽  
Oliver T. Carnell ◽  
Lucia Lafage ◽  
Joe Gray ◽  
Jacob Biboy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Ex Vivo ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Human Macrophages ◽  
Structure And Dynamics

Peptidoglycan is the major structural component of the Staphylococcus aureus cell wall, in which it maintains cellular integrity, is the interface with the host, and its synthesis is targeted by some of the most crucial antibiotics developed. Despite this importance, and the wealth of data from in vitro studies, we do not understand the structure and dynamics of peptidoglycan during infection. In this study we have developed methods to harvest bacteria from an active infection in order to purify cell walls for biochemical analysis ex vivo. Isolated ex vivo bacterial cells are smaller than those actively growing in vitro, with thickened cell walls and reduced peptidoglycan crosslinking, similar to that of stationary phase cells. These features suggested a role for specific peptidoglycan homeostatic mechanisms in disease. As S. aureus penicillin binding protein 4 (PBP4) has reduced peptidoglycan crosslinking in vitro its role during infection was established. Loss of PBP4 resulted in an increased recovery of S. aureus from the livers of infected mice, which correlated with enhanced fitness within murine and human macrophages. Thicker cell walls correlate with reduced activity of peptidoglycan hydrolases. S. aureus has a family of 4 putative glucosaminidases, that are collectively crucial for growth. Loss of the major enzyme SagB, led to attenuation during murine infection and reduced survival in human macrophages. However, loss of the other three enzymes Atl, SagA and ScaH resulted in clustering dependent attenuation, in a zebrafish embryo, but not a murine, model of infection. A combination of pbp4 and sagB deficiencies resulted in a restoration of parental virulence. Our results, demonstrate the importance of appropriate cell wall structure and dynamics during pathogenesis, providing new insight to the mechanisms of disease.

Antibacterial Mechanism of Long-Chain Polyphosphates in Staphylococcus aureus

1994 ◽  
Vol 57 (4) ◽  
pp. 289-294 ◽  
Author(s):  
RUBY M. LEE ◽  
PAUL A. HARTMAN ◽  
H. MICHAEL STAHR ◽  
DENNIS G. OLSON ◽  
FRED D. WILLIAMS
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Metal Ion ◽  
Antibacterial Mechanism ◽  
Essential Metals ◽  
Bacterial Leakage ◽  
Metal Ion Chelation ◽  
Free Metal ◽  
Long Chain

The results of previous studies indicated that the antibacterial effects of long-chain polyphosphates (sodium polyphosphate glassy [SPG] and sodium ultraphosphate [UP]) to Staphylococcus aureus ISP40 8325 could be attributed to damage to the cell envelope (cell wall or cell membrane). Also, Ca2+ (0.01 M) or Mg2+ (0.01 M) reversed the bactericidal and bacteriolytic effects of polyphosphates in S. aureus. In the present study, 0.4 M sodium chloride (NaCl) protected the cells from leakage caused by SPG and 0.6 M NaCl protected the cells from leakage by UP. Polymyxin, a peptide antibiotic that causes cell membrane damage, induced leakage even in the presence of 0.6 M NaCl. In the presence of 0.4 M NaCl, bacterial leakage was significantly reduced by disodium ethylenediamine tetraacetate (EDTA), a metal chelator that causes cell wall damage. Bacterial leakage by polyphosphates was significantly greater at pH 8 than at pH 6, which suggested that metal-ion chelation was involved in the antibacterial mechanism. A dialysis membrane (MWCO 100) was used to separate free metal and polyphosphate-bound metal. Levels of free Ca2+ and Mg2+ in polyphosphate-treated cells were significantly lower than those of the cells without polyphosphate. This free-metal dialysis study provided Chemical evidence to show that long-chain polyphosphates interacted with S. aureus cell walls by a metal-ion chelation mechanism. In addition, long-chain polyphosphates were shown to bind to the cell wall, chelate metals, and remain bound without releasing metal ions from the cell wall into the suspending medium. A hypothesis is proposed in which the antibacterial mechanism of long-chain polyphosphates is caused by binding of long-chain polyphosphates to the cell wall of early-exponential phase cells of S. aureus ISP40 8325. The polyphosphates chelate structurally essential metals (Ca2+ and Mg2+) of the cell wall, resulting in bactericidal and bacteriolytic effects. The structurally essential metals probably form cross bridges between the teichoic acid chains in the cell walls of gram-positive bacteria.

scholarly journals Effects of Black Pepper (Piper nigrum L.) Chloroform Extract on the Enzymatic Activity and Metabolism of Escherichia coli and Staphylococcus aureus

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Wenxue Chen ◽  
Lan Zou ◽  
Weijun Chen ◽  
Yueying Hu ◽  
Haiming Chen
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Antibacterial Activities ◽  
Black Pepper ◽  
Chloroform Extract ◽  
Piper Nigrum ◽  
Bacterial Cells ◽  
Bacterial Cell Walls

The chemical composition and antimicrobial mechanism of action of black pepper chloroform extract (BPCE) were investigated, as well as the potential antibacterial activities of BPCE against Escherichia coli and Staphylococcus aureus. The results showed that 1H-Cycloprop[e]azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene-, [1ar-(1aα,4aα,7β,7a,β,7bα.)]- (8.39%) and 2-methylene-4,8,8-trimethyl-4-vinyl-bicyclo[5.2.0]nonane (6.92%) were identified as the two primary components of BPCE. The release of intracellular transaminases from bacteria after being incubated with BPCE revealed that the bacterial cell walls and membranes were degraded and that protein synthesis was inhibited to some extent. The inhibition of bacterial Na+/K+-ATPase activity upon the addition of BPCE also indicated an enhanced permeability of bacterial cell membranes. Moreover, an analysis of hexokinase and pyruvate kinase activities showed that BPCE affected the metabolic rate of glycolysis and disrupted the normal metabolism of bacteria. This phenomenon was supported by an observed accumulation of lactic acid (LA) in the treated bacterial cells. Overall, our results indicated that BPCE damaged bacterial cell walls and membranes, which was followed by a disruption of bacterial cell respiration.

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