háček

A caron ( ˇ ) or háček (pronounced ; ), also known as a wedge, inverted circumflex, inverted hat, is a diacritic placed over certain letters to indicate present or historical palatalization, iotation, or postalveolar pronunciation in the orthography of some Baltic, Slavic, Finno-Lappic, and other languages.
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A HACEK organism is one of a set of slow-growing Gram negative bacteria that form a normal part of the human flora. They are a frequent cause of endocarditis in children.The name is formed from their initials:Haemophilus aphrophilus, Haemophilus parainfluenzae and Haemophilus paraphrophilusActinobacillus actinomycetemcomitansCardiobacterium hominis'''E'''ikenella corrodensKingella kingaeAll of these organisms are part of the normal oropharyngeal flora which grow slowly, prefer a carbon dioxide–enriched atmosphere and share an enhanced capacity to produce endocardial infections, especially in young children. Collectivelly, they account for 5-10% of cases of infective endocarditis involving native valves and are the most common gram-negative cause of endocarditis among people who do not use IV drugs. Because of their fastidious growth requirements, they have been a frequent cause of culture-negative endocarditis. Culture negative refers to its inability to produce a colony on regular agar plates, this is because they are fastidious (require a specific nutrient).
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