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Coagulase-negative Staphylococci (CONS), mainly Staphylococcus
epidermidis, hemolyticus, and hominis are currently the most
common pathogens responsible for nosocomial sepsis in high-risk
neonates(1). Though isolated rarely, Staphylococcus warneri is a
potentially dangerous pathogen in both immunocompetent and immuno-compromised
hosts(2-5). Staphylococcus warneri has been reported to
contribute to 8.5% and 16.6% of the cases of neonatal CONS
septicemia(4,5). A female neonate weighing 1088 grams was born at 28
weeks of gestation following emergency caesarian section for severe
pregnancy induced hyper-tension. The Apgar scores were 7 and 9 at 1 and
5 minutes, respectively. Her recovery from mild respiratory distress
syndrome, necessitating two doses of surfactant and mechanical
ventilation for 2 days, was uneventful. The initial blood count and
cultures did not indicate sepsis. Umbilical catheters were removed on
day 2. Enteral feeds commenced on day 5, were stopped on day 6 as she
became lethargic, hyperglycemic and had abdominal distension with ileus.
Vancomycin and cefotaxime were started after collecting blood for
culture and counts. Hemogram revealed: Hb 12.9 g/dl, WBC 10.2 × 109/mm3,
Platelets - 399×109/mm3,
Neutro-phils - 45% and toxic changes +++. The blood culture subsequently
grew Staphylococcus warneri sensitive to vancomycin, which was
continued for 7 days. Repeat blood culture on day 14 was sterile.
Further hospital stay was uneventful and she was discharged home on day
72. No investigations were undertaken to trace the source due to the
sporadic occurrence of the infection. Additionally, apart from
pre-maturity there were no obvious risk factos for nosocomial sepsis
like percutaneous central venous catheters, and assisted ventilation. A
retrospective review of data over previous 18 months revealed that Staphylococcus
warneri contributed to 6.4% (6/94) of the cases of neonatal CONS
septicemia, a lesser contribu-tion compared with 8.5% and 16.6% reported
earlier. Staphylococcus warneri is known to cause serious
infections like vertebral osteo-myelitis, and endocarditis in adults(2)
and bacteremia with clinical illness in children(3) and low-birth-weight
neonates(4,5). The clinical presentation of our case is a reminder of
the recommendation that identification of species level of coagulase-negative
staphylo-cocci may lead to appreciation of the importance of rarely
isolated bacteria such as Staphylococcus warneri as human
pathogens(4).
Acknowledgement
Cathy Engler, Department of Micro-biology, for
auditing the data on positive blood cultures to give the incidence of Staph.
warneri sepsis.
S.M. Jog,
S.K. Patole,
Department of Neonatology,
Kirwan Hospital for Women,
Townsville, Australia.
E-mail:
[email protected]
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1. Moreira BM, Daum RS. Antimicrobial
resistance in staphylococci. Pediatr Clin North Am. 1995; 42:
619-648.
2. Wood CA, Sewell DL, Strausbaugh LJ. Verte-bral
osteomyelitis and native valve endocarditis caused by Staphylococcus
warneri. Diagn Microbiol Infect Dis 1989; 12: 261-263.
3. Buttery JP, Easton M, Pearson SR, Hogg GG.
Pediatric bacteremia due to Staphylococcus warneri:
Microbiological, epidemiological, and clinical features, J Clin
Microbiol 1997; 35: 2174-2177.
4. Kacica MA, Horgan MJ, Preston KE, Lepow M,
Venezia RA. Relatedness of coagulase-negative staphylococci causing
bacteremia in low-birthweight infants. Infect Control Hosp Epidemiol
1994; 15: 658-662.
5. Kallman J, Kihlstrom E, Sjoberg L, Schollin J.
Increase of Staphylococci in neonatal septicemia: A fourteen-year
study. Acta Pediatr: 1977; 86: 533-538.
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