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David J Mcgee - One of the best experts on this subject based on the ideXlab platform.
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Arcanobacterium haemolyticum Utilizes Both Phospholipase D and Arcanolysin To Mediate Its Uptake into Nonphagocytic Cells.
Infection and immunity, 2019Co-Authors: Patrick S. Gellings, David J McgeeAbstract:Arcanobacterium haemolyticum is an emerging human pathogen that causes pharyngitis and wound infections. A few studies have suggested that A. haemolyticum is able to induce its uptake into nonphagocytic epithelial cells, but the bacterial factors associated with host cell invasion and the host cell processes involved have yet to be studied. We investigated how two A. haemolyticum virulence factors, arcanolysin (ALN) and phospholipase D (PLD), affect the ability of the bacteria to adhere to and subsequently invade Detroit 562 pharyngeal epithelial cells. The sphingomyelinase activity of phospholipase D was necessary to increase bacterial adherence, while the absence of a functional arcanolysin had no effect on A. haemolyticum adherence but did lead to a decrease in A. haemolyticum invasion into Detroit 562 cells. Because of the known roles of cholesterol-dependent cytolysins in disrupting calcium gradients and inducing F-actin-mediated bacterial internalization, we sought to determine whether ALN and PLD played a similar role in the ability of A. haemolyticum to invade nonphagocytic cells. Elimination of extracellular calcium and inhibition of the Arp2/3 complex or F-actin polymerization also caused a decrease in the ability of A. haemolyticum to invade Detroit 562 cells. Overall, our findings suggest that A. haemolyticum utilizes phospholipase D primarily for adherence and utilizes arcanolysin primarily for invasion into Detroit 562 cells in a process dependent on extracellular calcium and F-actin polymerization. Our work marks the first insight into how the individual activities of arcanolysin and phospholipase D affect A. haemolyticum host-pathogen interactions using the biologically relevant Detroit 562 cell line.
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Arcanobacterium haemolyticum Phospholipase D Enzymatic Activity Promotes the Hemolytic Activity of the Cholesterol-Dependent Cytolysin Arcanolysin.
Toxins, 2018Co-Authors: Patrick S. Gellings, David J McgeeAbstract:Arcanolysin, produced by the human pathogen Arcanobacterium haemolyticum, is a cholesterol-dependent cytolysin. To mediate the pore-formation process, arcanolysin is secreted by A. haemolyticum and then must interact with cholesterol embedded within a host membrane. However, arcanolysin must compete with membrane components, such as the phospholipid sphingomyelin, to interact with cholesterol and form pores. Cholesterol forms transient hydrogen bonds with the extracellular portion of sphingomyelin, shielding cholesterol from extracellular factors, including arcanolysin. A. haemolyticum also produces a sphingomyelin-specific phospholipase D, which removes the choline head from sphingomyelin, leaving cyclic-ceramide phosphate and eliminating the potential for cholesterol sequestration. We hypothesized that the enzymatic activity of phospholipase D decreases sphingomyelin-mediated cholesterol sequestration and increases cholesterol accessibility for arcanolysin. Using purified arcanolysin and phospholipase D, we demonstrate that the enzymatic activity of phospholipase D is necessary to promote arcanolysin-mediated hemolysis in both time- and concentration-dependent manners. Phospholipase D promotion of arcanolysin-mediated cytotoxicity was confirmed in Detroit 562 epithelial cells. Furthermore, we determined that incubating phospholipase D with erythrocytes corresponds with an increase in the amount of arcanolysin bound to host membranes. This observation suggests that phospholipase D promotes arcanolysin-mediated cytotoxicity by increasing the ability of arcanolysin to bind to a host membrane.
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RESEARCH ARTICLE Smooth and Rough Biotypes of Arcanobacterium haemolyticum Can Be Genetically Distinguished at the Arcanolysin Locus
2016Co-Authors: Haley S. Ruther, Osama Sammra, Christoph Lämmler, Kalyn Phillips, Dolores Ross, Alyssa Crawford, M. Paytonweidner, David J McgeeAbstract:Arcanobacterium haemolyticum is a Gram-positive, β-hemolytic emerging human pathogen that is classified into smooth or rough biotypes. This bacterial species is also a rare patho-gen of animals. Smooth biotypes possess smooth colony edges, are moderate to strong in β-hemolysis, and predominately cause wound infections. In contrast, rough biotypes pos-sess rough and irregular colony edges, have weak to no β-hemolytic activity, and predomi-nately cause pharyngitis. Using horse erythrocytes we confirmed that smooth isolates are generally more hemolytic than rough isolates. A hemolysin from A. haemolyticum, arcanoly-sin (aln/ALN), was recently discovered and is a member of the cholesterol-dependent cyto-lysin (CDC) family. PCR amplification of aln from all 36 smooth A. haemolyticum isolates yielded the expected 2.0 kb product. While 21 rough isolates yielded the 2.0 kb product, 16 isolates had a 3.2 kb product. The extra 1.2 kb segment was 99 % identical to IS911 (inser-tion sequence) from Corynebacterium diphtheriae. PCR amplification and sequence analy-sis of the upstream region of aln revealed ~40 nucleotide polymorphisms among 73 clinica
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Smooth and Rough Biotypes of Arcanobacterium haemolyticum Can Be Genetically Distinguished at the Arcanolysin Locus
PloS one, 2015Co-Authors: Haley S. Ruther, Osama Sammra, Christoph Lämmler, Kalyn Phillips, Dolores Ross, Alyssa Crawford, M. Payton Weidner, David J McgeeAbstract:Arcanobacterium haemolyticum is a Gram-positive, β-hemolytic emerging human pathogen that is classified into smooth or rough biotypes. This bacterial species is also a rare pathogen of animals. Smooth biotypes possess smooth colony edges, are moderate to strong in β-hemolysis, and predominately cause wound infections. In contrast, rough biotypes possess rough and irregular colony edges, have weak to no β-hemolytic activity, and predominately cause pharyngitis. Using horse erythrocytes we confirmed that smooth isolates are generally more hemolytic than rough isolates. A hemolysin from A. haemolyticum, arcanolysin (aln/ALN), was recently discovered and is a member of the cholesterol-dependent cytolysin (CDC) family. PCR amplification of aln from all 36 smooth A. haemolyticum isolates yielded the expected 2.0 kb product. While 21 rough isolates yielded the 2.0 kb product, 16 isolates had a 3.2 kb product. The extra 1.2 kb segment was 99% identical to IS911 (insertion sequence) from Corynebacterium diphtheriae. PCR amplification and sequence analysis of the upstream region of aln revealed ~40 nucleotide polymorphisms among 73 clinical isolates from Finland, Denmark, Germany and United States (Nebraska). Remarkably, multi-sequence alignments of the aln upstream region demonstrated that ~90% of the isolates phylogenetically clustered as either smooths or roughs. Differential restriction enzyme analysis of the aln upstream region also demonstrated that the aln upstream region of most (~75%) smooth isolates was cleaved with ClaI while this region in most (~86%) rough isolates was cleaved with XcmI. We conclude that the aln upstream region can be used to genetically distinguish between smooth and rough biotypes of this important emerging pathogen.
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Arcanolysin is a cholesterol-dependent cytolysin of the human pathogen Arcanobacterium haemolyticum
BMC Microbiology, 2011Co-Authors: B Helen Jost, Erynn A Lucas, Stephen J Billington, Adam J Ratner, David J McgeeAbstract:Background Arcanobacterium haemolyticum is an emerging human pathogen that causes pharyngitis, wound infections, and a variety of occasional invasive diseases. Since its initial discovery in 1946, this Gram positive organism has been known to have hemolytic activity, yet no hemolysin has been previously reported. A. haemolyticum also displays variable hemolytic activity on laboratory blood agar that is dependent upon which species the blood is derived. Results Here we describe a cholesterol-dependent cytolysin (CDC) secreted by A. haemolyticum , designated arcanolysin ( aln ), which is present in all strains (n = 52) tested by DNA dot hybridization. Among the known CDCs, ALN is most closely related to pyolysin (PLO) from Trueperella (formerly Arcanobacterium ) pyogenes . The aln probe, however, did not hybridize to DNA from T. pyogenes . The aln open reading frame has a lower mol %G+C (46.7%) than the rest of the A. haemolyticum genome (53.1%) and is flanked by two tRNA genes, consistent with probable acquisition by horizontal transfer. The ALN protein (~ 64 kDa) contains a predicted signal sequence, a putative PEST sequence, and a variant undecapeptide within domain 4, which is typically important for function of the toxins. The gene encoding ALN was cloned and expressed in Escherichia coli as a functional recombinant toxin. Recombinant ALN had hemolytic activity on erythrocytes and cytolytic activity on cultured cells from human, rabbit, pig and horse origins but was poorly active on ovine, bovine, murine, and canine cells. ALN was less sensitive to inhibition by free cholesterol than perfringolysin O, consistent with the presence of the variant undecapeptide. Conclusions ALN is a newly identified CDC with hemolytic activity and unique properties in the CDC family and may be a virulence determinant for A. haemolyticum .
P Carlson - One of the best experts on this subject based on the ideXlab platform.
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Antimicrobial Susceptibilities and Biotypes of Arcanobacterium haemolyticum Blood Isolates
European Journal of Clinical Microbiology and Infectious Diseases, 1999Co-Authors: P Carlson, J. Korpela, M. Walder, M. NymanAbstract:Isolates obtained from the blood of ten patients with Arcanobacterium haemolyticum septicaemia were biotyped as smooth or rough using morphological and biochemical criteria, and their susceptibilities to 18 antibacterial agents were determined. Nine of the clinical cases included here have not been reported previously and are discussed in brief. One of the strains was highly resistant to macrolides and clindamycin. With one exception, the strains belonged to the smooth biotype. The data presented here indicates that the treatment of systemic Arcanobacterium haemolyticum infections should be based on the antibacterial susceptibility profiles of individual strains and on the site of the infection.
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Evaluation of a commercial kit in the identification ofArcanobacterium haemolyticum andActinomyces pyogenes
European Journal of Clinical Microbiology and Infectious Diseases, 1994Co-Authors: P Carlson, S KontiainenAbstract:Listeria-Zym is a commercial kit designed to identify Listeria spp. within 4 h. Its ability to identify two clinically important aerobic catalasenegative, gram-positive rods, Arcanobacterium haemolyticum and Actinomyces pyogenes , was evaluated. Xylose fermentation and alpha-mannosidase tests differentiated Arcanobacterium haemolyticum (n=49) from Actinomyces pyogenes (n=24) strains.
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Antimicrobial susceptibility of Arcanobacterium haemolyticum.
Antimicrobial agents and chemotherapy, 1994Co-Authors: P Carlson, S Kontiainen, Olli-veikko RenkonenAbstract:The susceptibilities of 138 clinical isolates of Arcanobacterium haemolyticum to 11 antimicrobial agents were tested. All strains were susceptible to phenoxymethylpenicillin, cephalosporins, erythromycin, azithromycin, clindamycin, vancomycin, doxycycline, and ciprofloxacin but were resistant to trimethoprim-sulfamethoxazole.
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Biotypes of Arcanobacterium haemolyticum.
Journal of clinical microbiology, 1994Co-Authors: P Carlson, K Lounatmaa, S KontiainenAbstract:Colony morphology, beta hemolysis on horse blood agar, beta-glucuronidase activity, and ability to ferment sucrose and/or trehalose defined two biotypes of Arcanobacterium haemolyticum. One, the smooth type, grew as smooth, beta-hemolytic colonies and was beta-glucuronidase negative but often fermented sucrose and/or trehalose, while the other, the rough type, grew as rough colonies and was nonhemolytic, beta-glucuronidase positive, and negative for sucrose and trehalose fermentation. About 75% of the A. haemolyticum strains studied (n = 138) were of the smooth type. The smooth type predominated in wound infections, while the rough type was isolated almost exclusively from respiratory tract specimens; thus, 84% of the smooth-type strains were derived from wounds and 91% of the rough-type strains were isolated from respiratory tracts.
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Evaluation of a commercial kit in the identification of Arcanobacterium haemolyticum and Actinomyces pyogenes.
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 1994Co-Authors: P Carlson, S KontiainenAbstract:Listeria-Zym is a commercial kit designed to identifyListeria spp. within 4 h. Its ability to identify two clinically important aerobic catalasenegative, gram-positive rods,Arcanobacterium haemolyticum andActinomyces pyogenes, was evaluated. Xylose fermentation and alpha-mannosidase tests differentiatedArcanobacterium haemolyticum (n=49) fromActinomyces pyogenes (n=24) strains.
Beng Kuan Chan - One of the best experts on this subject based on the ideXlab platform.
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Arcanobacterium haemolyticum bacteraemia and soft-tissue infections: case report and review of the literature.
The Journal of infection, 2005Co-Authors: Thean Yen Tan, Helen Thomas, Beng Kuan ChanAbstract:Five cases of bacteraemia with Arcanobacterium haemolyticum in association with soft-tissue infections are reported from immunocompetent patients. A review of all A. haemolyticum isolates from our institution over a three-year period reveals that 94% were cultured from patients with soft-tissue infections, and 72% of all patients had concomitant diabetes mellitus. Arcanobacterium haemolyticum is an uncommon cause of bacteraemic soft-tissue infections, and diabetes mellitus may be an associated risk factor.
S Kontiainen - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of a commercial kit in the identification ofArcanobacterium haemolyticum andActinomyces pyogenes
European Journal of Clinical Microbiology and Infectious Diseases, 1994Co-Authors: P Carlson, S KontiainenAbstract:Listeria-Zym is a commercial kit designed to identify Listeria spp. within 4 h. Its ability to identify two clinically important aerobic catalasenegative, gram-positive rods, Arcanobacterium haemolyticum and Actinomyces pyogenes , was evaluated. Xylose fermentation and alpha-mannosidase tests differentiated Arcanobacterium haemolyticum (n=49) from Actinomyces pyogenes (n=24) strains.
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Antimicrobial susceptibility of Arcanobacterium haemolyticum.
Antimicrobial agents and chemotherapy, 1994Co-Authors: P Carlson, S Kontiainen, Olli-veikko RenkonenAbstract:The susceptibilities of 138 clinical isolates of Arcanobacterium haemolyticum to 11 antimicrobial agents were tested. All strains were susceptible to phenoxymethylpenicillin, cephalosporins, erythromycin, azithromycin, clindamycin, vancomycin, doxycycline, and ciprofloxacin but were resistant to trimethoprim-sulfamethoxazole.
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Biotypes of Arcanobacterium haemolyticum.
Journal of clinical microbiology, 1994Co-Authors: P Carlson, K Lounatmaa, S KontiainenAbstract:Colony morphology, beta hemolysis on horse blood agar, beta-glucuronidase activity, and ability to ferment sucrose and/or trehalose defined two biotypes of Arcanobacterium haemolyticum. One, the smooth type, grew as smooth, beta-hemolytic colonies and was beta-glucuronidase negative but often fermented sucrose and/or trehalose, while the other, the rough type, grew as rough colonies and was nonhemolytic, beta-glucuronidase positive, and negative for sucrose and trehalose fermentation. About 75% of the A. haemolyticum strains studied (n = 138) were of the smooth type. The smooth type predominated in wound infections, while the rough type was isolated almost exclusively from respiratory tract specimens; thus, 84% of the smooth-type strains were derived from wounds and 91% of the rough-type strains were isolated from respiratory tracts.
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Evaluation of a commercial kit in the identification of Arcanobacterium haemolyticum and Actinomyces pyogenes.
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 1994Co-Authors: P Carlson, S KontiainenAbstract:Listeria-Zym is a commercial kit designed to identifyListeria spp. within 4 h. Its ability to identify two clinically important aerobic catalasenegative, gram-positive rods,Arcanobacterium haemolyticum andActinomyces pyogenes, was evaluated. Xylose fermentation and alpha-mannosidase tests differentiatedArcanobacterium haemolyticum (n=49) fromActinomyces pyogenes (n=24) strains.
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Alpha-mannosidase: a rapid test for identification of Arcanobacterium haemolyticum.
Journal of clinical microbiology, 1994Co-Authors: P Carlson, S KontiainenAbstract:A 4-h alpha-mannosidase test for identification of Arcanobacterium haemolyticum strains (n = 139) and differentiation of A. haemolyticum from Actinomyces pyogenes strains (n = 30) and other gram-positive rods was evaluated. Practically all A. haemolyticum strains (138 of 139) and the Listeria monocytogenes type strain were alpha-mannosidase positive, while all A. pyogenes strains and Corynebacterium (n = .25) strains as well as the Rhodococcus equi and Erysipelothrix rhusiopathiae type strains were negative. The rapid alpha-mannosidase test, in conjunction with a Gram stain and catalase and reverse CAMP tests, was useful in identification of A. haemolyticum and in differentiation of A. haemolyticum from A. pyogenes and Corynebacterium spp.
Tove Ejlertsen - One of the best experts on this subject based on the ideXlab platform.
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Systemic and deep-seated infections caused by Arcanobacterium haemolyticum.
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 1998Co-Authors: Robert Skov, A. K. Sanden, V. H. Danchell, K. Robertsen, Tove EjlertsenAbstract:Arcanobacterium haemolyticum has been implicated mainly in non-streptococcal pharyngitis and wound infections. Rarely, it has been reported to cause systemic infection, often in combination with other pathogens. Two cases of systemic and deep-seated infections caused byArcanobacterium haemolyticum are reported, and the literature is reviewed. Sixteen cases of bacteremia and seven cases of non-bacteremic deep-seated have been published previously. Eight of the bacteremic and two of the non-bacteremic cases occurred in younger, apparently healthy immunocompetent patients. Six patients had infections of the central nervous system. The optimal treatment of infections caused byArcanobacterium haemolyticum is not known. Although in vitro susceptibility tests have demonstrated tolerance ofArcanobacterium haemolyticum to penicillin, penicillins with or without aminoglycosides have been the most widely used antibiotics, in most cases with success.
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Systemic and deep-seated infections caused byArcanobacterium haemolyticum
European Journal of Clinical Microbiology and Infectious Diseases, 1998Co-Authors: R. L. Skov, A. K. Sanden, V. H. Danchell, K. Robertsen, Tove EjlertsenAbstract:Arcanobacterium haemolyticum has been implicated mainly in non-streptococcal pharyngitis and wound infections. Rarely, it has been reported to cause systemic infection, often in combination with other pathogens. Two cases of systemic and deep-seated infections caused by Arcanobacterium haemolyticum are reported, and the literature is reviewed. Sixteen cases of bacteremia and seven cases of non-bacteremic deep-seated have been published previously. Eight of the bacteremic and two of the non-bacteremic cases occurred in younger, apparently healthy immunocompetent patients. Six patients had infections of the central nervous system. The optimal treatment of infections caused by Arcanobacterium haemolyticum is not known. Although in vitro susceptibility tests have demonstrated tolerance of Arcanobacterium haemolyticum to penicillin, penicillins with or without aminoglycosides have been the most widely used antibiotics, in most cases with success.