As the medical community continues to navigate the complex world of infectious diseases, a recent case involving a 4-year-old girl has sparked renewed interest in a relatively obscure bacterium – Ewingella americana (Ea). This article examines the significance of Ea in humans, particularly in an otherwise healthy pediatric patient, and discusses the wider implications for clinical practice.
Ewingella americana, first described in 1983, has lingered at the fringes of medical research due to its rarity and the predominance of cases in immunocompromised individuals. This case, as detailed in BMC Infectious Diseases, DOI: 10.1186/s12879-019-4021-4, presents a healthy 4-year-old hospitalized with a severe respiratory infection, raising questions about Ea’s role as a pathogen and how it should be managed (Esposito et al., 2019).
The Case Overview
The girl, with no significant medical history, developed a productive cough lasting three weeks and a high fever accompanied by tachypnea. Physical examination revealed a febrile state, dyspnea, and signs of respiratory distress. A chest X-ray identified segmental consolidation in the lingula of the left lung, and laboratory tests showed leukocytosis.
What made the case stand out was the isolation of Ewingella americana from the patient’s respiratory secretions, an unexpected find given her lack of comorbidities and the bacteria’s reputation as an opportunistic pathogen primarily affecting those with compromised immune systems.
The Nature of Ewingella Americana
Ea is a Gram-negative, lactose-fermenting bacterium in the family Enterobacteriaceae. It exhibits oxidase-negative and catalase-positive reactions and has been isolated from various clinical and environmental specimens (Grimont et al., 1983). Despite its discovery decades ago, there has been limited understanding of its pathogenic potential and the appropriate therapeutic strategies.
Historical Perspective and Case Reports
Following its identification, Ea mostly appeared in case reports associated with immunocompromised patients or those with other underlying conditions. From keratoconjunctivitis (Da Costa et al., 2000) to peritonitis in peritoneal dialysis patients (Kati et al., 1999), the reported infections have been varied but consistently linked to predisposing factors.
A review of unusual organisms causing eye infections, for instance, mentioned a case of keratoconjunctivitis due to Ea (Da Costa et al., 2000), highlighting its capacity to colonize and infect different body sites. Another report documented Ea’s involvement in pneumonia cases with renal failure patients, emphasizing the bacterium’s emergence in at-risk populations (Ryoo et al., 2005).
Antibiotic Sensitivity of Ewingella Americana
The susceptibility of Ea to various antibiotics has been a subject of study. Reports have indicated varied sensitivities, with some Ea strains displaying resistance to multiple drugs (Stock et al., 2003). This presents a challenge in choosing effective therapeutic options, although certain aminoglycosides, fluoroquinolones, and β-lactam antibiotics have been effective in some instances.
The Conundrum: Opportunist or Pathogen?
The infection in this otherwise healthy child raises questions about Ea’s pathogenic capabilities. Could it be a pathogen in its own right? Or are occurrences in healthy individuals so rare that they do not alter the essential understanding of Ea as an opportunistic agent?
The Treatment Dilemma
Another point of consideration is the necessity and choice of antibiotic therapy. Given the mild nature of the infection in this pediatric case, antibiotic use was debated (Esposito et al., 2019). There is an ongoing discourse regarding the appropriate management of community-acquired pneumonia in children, gauging the necessity and duration of antibiotic treatment (Esposito et al., 2012).
Implications for Diagnosis and Management
Considering the rarity of Ea infections, especially in healthy individuals, clinicians are urged to be vigilant and consider the bacterium in their differential diagnosis when encountering unexplained infections. As evidenced by resistance patterns, treatment may prove tricky, and in some cases, antibiotic therapy might not be mandatory—especially in mild presentations in otherwise healthy children.
Ethics and Future Directions
The case followed ethical protocols, with the Ethics Committee of Umbria Region, Perugia, Italy, approving the management and treatment of the child (2018-PED-04). Written informed consent was obtained from the parents for both the management and the publication of the case report.
Given the unusual presentation in this case, further research is warranted to explore Ea’s behavior and treatment in the pediatric population. Researchers and healthcare providers should remain open to the possible evolution of Ea’s pathogenic profile and the need for updated clinical guidelines.
Conclusion
This intriguing case of Ea infection in a healthy child contradicts the usual perception of the bacterium as solely an opportunistic pest. It calls for a reevaluation of Ea’s pathogenicity and the associated clinical strategies. As such, the medical community should maintain awareness of Ea as a potential agent in uncommon presentations, ensuring that diagnosis and treatment plans evolve with the expanding understanding of this bacterium.
References
1. Esposito, S., Miconi, F., Molinari, D., Savarese, E., Celi, F., Marchese, L., Valloscuro, S., Miconi, G., & Principi, N. (2019). What is the role of Ewingella americana in humans? A case report in a healthy 4-year-old girl. BMC Infectious Diseases, 19(1), 386. DOI:10.1186/s12879-019-4021-4
2. Grimont, P. A., Farmer, J. J., Grimont, F., Asbury, M. A., Brenner, D. J., & Deval, C. (1983). Ewingella americana gen.Nov., sp.nov., a new Enterobacteriaceae isolated from clinical specimens. Ann Microbiol (Paris), 134A(39), 52.
3. Kati, C., Bibashi, E., Kokolina, E., Sofianou, D. (1999). Case of peritonitis caused by Ewingella americana in a patient undergoing continuous ambulatory peritoneal dialysis. J Clin Microbiol, 37, 3733-3734.
4. Ryoo, N. H., Ha, J. S., Jeon, D. S., Kim, J. R., Kim, H. C. (2005). A case of pneumonia caused by Ewingella americana in a patient with chronic renal failure. J Korean Med Sci, 20(1), 143-145.
5. Da Costa, P. S., Tostes, M. M., de Carvalho Valle, L. M. (2000). A case of keratoconjunctivitis due to Ewingella americana and a review of unusual organisms causing external eye infections. Braz J Infect Dis, 4(4), 262-267.
Keywords
1. Ewingella Americana Pathogenicity
2. Pediatric Pneumonia Bacteria
3. Rare Bacterial Infections Children
4. Ewingella Americana Infection Treatment
5. Community-Acquired Pneumonia Antibiotics