Letters to the Editor

Indian Pediatrics 2001; 38: 110-111

Vertical Transmission of Citrobacter freundii

Citrobacter species, a gram negative bacilli, are known to cause sepsis, meningitis, brain abscess, pneumonia, arthritis and endocarditis in newborns. Most of the reported infections have been acquired nosocomially, resulting in high mortality(1,2). Vertical transmission from mother to infant appears infrequent and has been documented with C. koseri in only two reports so far(2,4). In this communication we highlight a case where a newborn infant acquired C. freundii from the mother.

A 32 week preterm weighing 1.55 kg was delivered vaginally to a multigravida mother. The mother was admitted with a history of leaking per vagina for 11 days and fever for one week prior to delivery. Suspecting chorioamnionitis, a high vaginal swab of the mother was sent for culture. Gastric aspirate of the newborn, collected within 30 minutes of birth revealed thick purulent contents full of polymorphs. Gram stain did not demonstrate any organism. Micro ESR at birth was found elevated (4 mm). Respiratory distress developed within 2 hours of birth and bilateral mucopurulent eye discharge was noticed at 12 hours of age. Rest of the examination was normal. Chest radiograph revealed bilateral upper zone consolidation. A complete sepsis workup was done and intravenous antibiotics (ciprofloxacin and gentamicin) were started. The respiratory distress settled down by third day and the child could be started on feeds later. He was eventually discharged after receiving 10 days of antibiotics.

Cultures taken from the maternal high vaginal swab, and neonatal gastric aspirate and conjunctival swabs reported Citrobacter freundii with a similar sensitivity to cipro-floxacin, cefotaxime, gentamicin and chlor-amphenicol. Blood culture was sterile.

Citrobacter species accounts for 2-30% of all infections in neonatal units, most often resulting in late onset sepsis. In the present case, gastric aspirate obtained soon after birth was positive for Citrobacter, child also developed early onset sepsis with pneumonia and conjunctivitis within 24 hours of birth. This suggest a maternal-fetal transmission of the organism. Maternal fever, prolonged rupture of membrances, and polymorphs in the gastric aspirate suggested chorioamnionitis.

In a bacteriological study of maternal-fetal infections at Brazaville, Citrobacter was found to be harbouring in the vaginal secretions in around 3.6% of all cases(5). The mode of acquisition in vagina is speculated to be either a long standing UTI or chronic carriage of the microbe in the feces. As there was no history of diarrhea, this mother could have acquired the organism following an episode of UTI with Citrobacter though this could not be confirmed.

Ribotyping and pulsed field gel electro-phoresis to examine fragment length poly-morphism within the DNA of maternal and neonatal isolates would have been the ideal methods to document the three isolates as the same strain but were not performed due to lack of facilities. However, similar sensitivity patterns of the three isolates and lack of isolation of Citrobacter freundii from any of the cultures taken in the neonatal unit during the study period strongly suggested a common strain being involved in vertical transmission. Moreover, hosptial acquired strains are usually multidrug resistant including cephalosporins. The sensitivity pattern of our isolates also suggested a community acquired organism that was sensitive to all antibiotics. The child responded well to a combination of cipro-floxacin and gentamicin, hitherto unused for neonatal Citrobacter sepsis.

Epidemiological studies are advocated to find out the prevalence of vaginal colonization with Citrobacter, its probable route of acquisition, and impact on neonatal outcome.

Piyush Gupta,
Deepa Gupta,
*N.P. Singh,
M.M.A. Faridi,
Department of Pediatrics and *Microbiology,
University College of Medical Sciences and
G.T.B. Hospital, Delhi 110 095, India.
E-Mail: [email protected]

1. Saraswati K, De A, Gogate A, Fernandes AR. Citrobacter sepsis in infants. Indian Pediatr 1995; 32: 359-362.

2. Sugandhi RP, Beena VK, Shivananda PG, Baliaga M. Citrobacter sepsis in infants. Indian J Pediatr 1992; 59: 309-312.

3. Papasian CJ, Kinney J, Coffman S, Hollis RJ, Pfaller MA. Transmission of Citrobacter koseri from mother to infant documented by ribotyping and pulsed field gel electrophoresis. Diagn Microbiol Infect Dis 1996; 26: 63-67.

4. Finn A, Talbot GH, Anday E, Skros M, Provencher M, Hoegg C. Vertical transmission of Citrobacter diversus from mother to infant. Pediatr Infect Dis J 1988; 7: 293-294.

5. Yala F, Biendo M, Odongo I, Kounko R. Virological and bacteriological study of materno-fetal infections in Brazzaville. Bull Soc Pathol Exot 1991; 84: 627-634.