Prototheca zopfii

Prototheca zopfii is an ubiquitous achlorophyllic (without chlorophyll) green alga.^[1] It is a known cause of mastitis in cattle.

Prototheca zopfii
Photomicrograph depicting the histopathology associated with protothecosis in a dog due to Prototheca zopfii
Scientific classification
Clade:	Viridiplantae
Division:	Chlorophyta
Class:	Trebouxiophyceae
Order:	Chlorellales
Family:	Chlorellaceae
Genus:	Prototheca
Species:	P. zopfii
Binomial name
Prototheca zopfii W.Krüger

Taxonomy

The genome of this organism's mitochondrion and plastid were first sequenced in 2018.^[2] Polymerase chain reaction and restriction fragment length polymorphism analysis are useful tool for rapid confirmative diagnosis.^[3]

Biology

Prototheca zopfii is ubiquitous in nature, but mainly associated with wet areas and places with high amounts of organic matter. It can be found in tanks, well water, teat-dip containers, and milking machines.^[4]

Prototheca zopfii grows in aerobic conditions and reproduce asexually by endosporulation.^[5] Sabouraud agar is used as a cultural medium.^[6]

Pathogenicity

Prototheca zopfii is an opportunistic environmental pathogen. The species can infect man and animal, causing mastitis.^[3] P. zopfii can cause bovine clinical mastitis in high milk-yielding cows.^[7] Genotypes I and III, traditionally, are thought not to be involved in the pathogenicity of mastitis and to be pollutants of milk, whereas genotype II is believed the main cause of mastitis.^[3] However, in 2017, three cases of human protothecosis due to P. zopfii genotype I have been reported in China.^[8]

Outbreaks

Bovine mastitis outbreaks by P. zopfii is a global problem. It is reported from Europe,^[9][10][11] Asia,^[12] North America,^[13][14] and South America.^[15][16]

Antimicrobial therapy

Prototheca zopfii is less susceptible or completely resistant to clotrimazole, fluconazole, econazole, flucytosine, cefoperazone, cephalexin, enrofloxacin, lincomycin, oxytetracycline, miconazole, colistin, a combination of amoxicillin with clavulanic acid, enrofloxacin, amoxicillin, tetracycline, penicillin, lincomycin, and novobiocin, whereas drugs such as nystatin, ketoconazole, and amphotericin B are effective against algae isolated from milk of mastitis-affected cows.^[6]