A coccobacillus is a type of rod-shaped bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

. The word coccobacillus reflects an intermediate shape between coccus (spherical) and bacillus (elongated). Coccobacilli rods are so short and wide that they resemble cocci. Haemophilus influenzae

Haemophilus influenzae

Haemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...

and Chlamydia trachomatis

Chlamydia trachomatis

Chlamydia trachomatis, an obligate intracellular human pathogen, is one of three bacterial species in the genus Chlamydia. C. trachomatis is a Gram-negative bacteria, therefore its cell wall components retain the counter-stain safranin and appear pink under a light microscope.The inclusion bodies...

are coccobacilli. Aggregatibacter actinomycetemcomitans

Aggregatibacter actinomycetemcomitans

Aggregatibacter actinomycetemcomitans is an oral commensal found also in severe infections in the oral cavity, mainly the periodontium. A. actinomycetemcomitans, previously Actinobacillus actinomycetemcomitans, is a gram negative facultative non-motile rod. It is also associated with non-oral...

is a gram-negative coccobacillus that is prevalent in subgingival plaques. Acinetobacter

Acinetobacter

Acinetobacter [asz−in−ée−toe–back−ter] is a genus of Gram-negative bacteria belonging to the Gammaproteobacteria. Acinetobacter species are non-motile and oxidase-negative, and occur in pairs under magnification....

strains may grow on solid media as coccobacilli. Bordetella pertussis

Bordetella pertussis

Bordetella pertussis is a Gram-negative, aerobic coccobacillus of the genus Bordetella, and the causative agent of pertussis or whooping cough. Unlike B. bronchiseptica, B. pertussis is non-motile. Its virulence factors include pertussis toxin, filamentous hæmagglutinin, pertactin, fimbria, and...

is a gram-negative coccobacillus responsible for causing whooping cough.

Coxiella burnetti is also a coccobacillus.

Bacteria from the Brucellae genus are medically important coccobacilli that cause brucellosis.

Haemophilus ducreyi

Haemophilus ducreyi

Haemophilus ducreyi is a fastidious gram-negative coccobacillus causing the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Another early symptom is dark or light green shears in excrement...

is another medically important gram-negative coccobacillus and is observed in sexually transmitted disease, chancroid, of third-world countries.