Gram negative Coccobacilli include following pathogenic bacteria;
1. Bordetella
2. Hemophilus
1. Bordetella
Causing whooping cough
It is caused by bordetella pertussis.
It is acute infection disease.
It cause pertussis or whooping cough. " Bordetella pertussis"
Morphology
Gram negative, strict aerobic, encapsulated Coccobacilli, non sporing, motile.
Size; 0.8 micrometre X 0.4 micrometre
Aerobic in nature.
Temperature for growth is 35 - 36 degree Celsius.
Biochemically inactive.
Source and Mode of Transmission
Present in nasopharynx and respiratory tract mucosa.
Transmitted by droplets
Spread by coughing
By direct contact
Pathogenesis
Incubation period for pertussis rangs from one to three weeks
The disease is divided into three phases;
1. Catarrhal Phase
2. Paroxysmal phase
3. Convalescent phase
1. Catarrhal Phase
Mild fever, conjunctival inection, malaise, rhinorrhea.
2. Paroxysmal phase
Cough in bouts
Vomiting
Pneumonia
Otitis media
CNS dysfunction
3. Convalescent phase
Frequency and severity of cough decreasing gradually.
Lab Diagnosis
Specimen collection
Respiratory secretion
Gram staining
Shows small gram -ve Coccobacilli.
Cultural characteristics and culture
Fluorescent antibody technique is more preferable for bacilli in respiratory secretion.
Aerobic, grow at best at 35 -36 degree Celsius.
Biochemical reaction
Serological investigation
Raise in antibody titre of antibody in diagnostic.
Detect presence and measures amount of antibodies with person blood.
Treatment
Erythromycin is the drug of choice for infection.
If erythromycin treatment fails, then trimethoprium, sulfamethonazole ia an alternative choice.
Prevention
Immunization of infants and children vaccine is generally combine with diphtheria and tetanus toxoid (triple vaccine; DPT).
Avoiding contact with infectious person is helpful in preventing infection.
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