P.O. Box 131375, Bryanston, 2074 Ground Floor, Block 5 Bryanston Gate, 170 Curzon Road Bryanston, Johannesburg, South Africa www.thistle.co.za Tel: +27 (011) 463 3260 Fax: +27 (011) 463 3036 Fax to Email: + 27 (0) 86-557-2232 e-mail : [email protected]

Please read this section first The HPCSA and the Med Tech Society have confirmed that this clinical case study, plus your routine review of your EQA reports from Thistle QA, should be documented as a “Journal Club” activity. This means that you must record those attending for CEU purposes. Thistle will not issue a certificate to cover these activities, nor send out “correct” answers to the CEU questions at the end of this case study.

The Thistle QA CEU No is: MT-2015/009.

Each attendee should claim THREE CEU points for completing this Quality Control Journal Club exercise, and retain a copy of the relevant Thistle QA Participation Certificate as proof of registration on a Thistle QA EQA.

MICROBIOLOGY LEGEND

CYCLE 38 ORGANISM 1

Arcanobacterium haemolyticum

Arcanobacterium haemolyticum was first described by MacLean et al. in 1946 as a pathogen in cases of exudative pharyngitis and soft-tissue infections. In 1982 the previously named Corynebacterium haemolyticum was included in a new genus to reflect major differences in cell wall components and chemotaxonomic characters, the genus Arcanobacterium. Currently, there are nine identified species within this genus of which A. haemolyticum, A. pyogenes and A. bernardiae have been recovered from clinical specimens.

It is a catalase-negative, aerobic, beta-haemolytic, nonmotile, irregular gram-positive to gram-variable rod that may be misidentified as Streptococcus species, Corynebacterium species, or A. pyogenes. Microscopic morphology differentiates A. haemolyticum from Streptococcus species; beta-haemolysis and absence of catalase from Corynebacterium species; and failure to ferment xylose, and reverse CAMP-test from A. pyogenes.

Growth is enhanced in a blood enriched medium at 37ºC in the presence of 5-10% CO2. Haemolysis is best observed in a CO2-enriched atmosphere, and on media with human or horse blood. A. haemolyticum exists in smooth and rough biotypes. The smooth biotype predominates in wound infections and the rough biotype in respiratory tract infections.

EPIDEMIOLOGY Man is the primary environmental reservoir.

CLINICAL MANIFESTATIONS Arcanobacterium haemolyticum is an organism that most often causes infections and illnesses in teenagers and young adults. The infection is spread from person to person, apparently through respiratory tract droplets that carry the bacteria directly to the next person’s eyes or nose. The most common symptom associated with A. haemolyticum is a sore throat, although other symptoms such as a fever, swollen lymph glands, and an itchy skin rash occur frequently as well. The rash begins on the extremities and spreads to the chest and back. Antibiotics, typically erythromycin, can be used to treat this infection. The symptoms quickly clear up when taking these medicines, although the disease is likely to get better on its own without treatment.

Thistle QA is a SANAS accredited organisation, No: PTS0001 Accredited to ISO 17043 Certificate available on request or at www.sanas.co.za Page 1 of 3

P.O. Box 131375, Bryanston, 2074 Ground Floor, Block 5 Bryanston Gate, 170 Curzon Road Bryanston, Johannesburg, South Africa www.thistle.co.za Tel: +27 (011) 463 3260 Fax: +27 (011) 463 3036 Fax to Email: + 27 (0) 86-557-2232 e-mail : [email protected]

LABORATORY DIAGNOSIS Although A. haemolyticum is a beta-haemolytic organism, the haemolysis is less well defined than that of beta- haemolytic streptococci and may be overlooked in cultures with heavy growth of commensal throat flora. The colony size and degree of haemolysis vary considerably with the types of blood cells, medium bases, and atmosphere used. There are significant differences with regard to the impact of atmosphere, time of incubation, and culture media for isolation.

A. haemolyticum does not produce catalase. Esculin, gelatin, urea, and casein are not hydrolysed. Acid is produced from glucose, lactose, maltose, and fructose but not from xylose, mannitol, or mannose. It produces DNase and is resistant to bacitracin. Inhibition of the haemolytic zone of Staphylococcus aureus (reverse CAMP test) is useful in its identification. A cross-reaction with group B-streptococci antiserum could be observed. Incubation for 72 hours reveals the organism’s colony features: circular, discoid, opaque, and whitish pinpoint colonies, 0.5 mm in diameter, with a narrow zone of complete haemolysis on sheep or horse blood agar.

A. haemolyticum colonies on a blood agar plate, beta- Arcanobacterium haemolyticum on gram stain haemolysis is demonstrated with transmitted light

PATHOGENESIS A. haemolyticum produces uncharacterized haemolytic agent(s) and two biochemically defined extracellular products, a neuraminidase, and a phospholipase D genetically and functionally similar to Corynebacterium pseudotuberculosis phospholipase D. This phospholipase is a lipid-hydrolysing enzyme that is damaging to mammalian cell membranes, enhances bacterial adhesion and promotes host cell necrosis following invasion, and therefore, may be important in the disease pathogenesis. Recently a cholesterol-dependent cytolysin, designated arcanolysin, has been identified, and may be a virulence determinant.

Thistle QA is a SANAS accredited organisation, No: PTS0001 Accredited to ISO 17043 Certificate available on request or at www.sanas.co.za Page 2 of 3

P.O. Box 131375, Bryanston, 2074 Ground Floor, Block 5 Bryanston Gate, 170 Curzon Road Bryanston, Johannesburg, South Africa www.thistle.co.za Tel: +27 (011) 463 3260 Fax: +27 (011) 463 3036 Fax to Email: + 27 (0) 86-557-2232 e-mail : [email protected]

SUSCEPTIBILITY IN VITRO AND IN VIVO In 2006 the Clinical and Laboratory Standards Institute (CLSI), and in 2014 the European Committee on Antimicrobial Susceptibility Testing (EUCAST) defined standardized methods for susceptibility of Corynebacterium that could be used with A. haemolyticum. In vitro testing of A. haemolyticum isolated from human infections shows that it was generally susceptible to penicillins, cephalosporins, carbapenems, macrolides, clindamycin, rifampin, glycopeptides, gentamicin and ciprofloxacin, but resistant to trimethoprim- sulfamethoxazole. Bactericidal tests, however, have shown most isolates of A. haemolyticum to be tolerant to penicillin, which may lead to treatment failures. Strains of A. haemolyticum were highly susceptible to the bactericidal action of gentamicin.

References 1. http://www.antimicrobe.org/b78.asp Arcanobacterium haemolyticum Authors: Juan-Ignacio Alós, Ph.D. 2. https://www.google.co.za/search?q=arcanobacterium+haemolyticum+images 3. http://emedicine.medscape.com/article/1054547-overview

Questions 1. How would you identify a patient with Arcanobacterium haemolyticum infection in your lab? 2. Discuss the morphological characteristics of Arcanobacterium haemolyticum? 3. Discuss the pathophysiology of Arcanobacterium haemolyticum

Thistle QA is a SANAS accredited organisation, No: PTS0001 Accredited to ISO 17043 Certificate available on request or at www.sanas.co.za Page 3 of 3