Clinical Study
Multidrug-resistant Achromobacter animicus causing wound infection in a street child in Mwanza, Tanzania

https://doi.org/10.1016/j.diagmicrobio.2017.02.002Get rights and content

Highlights

  • Fifth case of Achromobacter animicus worldwide and first case of wound infection

  • First case report of Achromobacter species infection in Africa

  • Unlike most Achromobacter species, the isolate was resistant to trimethoprim-sulfamethoxazole in addition to its cephalosporin resistance.

  • The isolate was sensitive to ciprofloxacin and gentamicin.

  • The infection of the case with unusual pathogen displaying a multi-resistant phenotype demonstrates the importance of microbiological laboratory capacity in Africa.

Abstract

Achromobacter animicus (A. animicus) is an aerobic, motile, gram-negative, non-fermenting small bacillus that can also grow anaerobically with potassium nitrate. It has been isolated from sputum of humans suffering from respiratory infections. Literature regarding the role of A. animicus in wound infections is limited. We report a first case of a chronic post-traumatic wound infection caused by a multidrug-resistant A. animicus in a street child from Africa and accompanied diagnostic challenges.

Introduction

Achromobacter species, previously described as aquatic environmental bacteria have recently been frequently isolated from cystic fibrosis patients (Dupont et al., 2015). There are few reports of Achromobacter xylosoxidans (A. xylosoxidans) causing skin and soft tissue infections, bacteremia and osteomyelitis (Shinha and Oguagha, 2015, Spear et al., 1988, Tena et al., 2014). Efflux pumps and production of class D beta-lactamase enzymes have been associated with intrinsic resistance of A. xylosoxidans to antimicrobials (Doi et al., 2008). In addition, other acquired aminoglycosides and beta-lactam resistance genes have recently been detected in A. xylosoxidans (Hu et al., 2015). A. animicus is an aerobic, motile, gram-negative, non-fermenting rod which was first isolated in 2006 from a cystic fibrosis patient (Vandamme et al., 2013). Up to the present time, there is no report of A. animicus causing wound infection and the mechanisms of resistance and genes involved in resistance are not well understood. In this report, we describe a case of wound infection caused by A. animicus and the involved mechanisms of resistance.

Section snippets

Case report

A 14-year-old male from Igoma ward in urban Mwanza was enrolled in a study via the founded Wound Care Project on 16th April, 2015. He was a street child type one i.e. those who spend the day on streets and at night they either sleep at home or in street children institutions (Ayaya and Esamai, 2001). His survival relied on selling scrap metals. His main complaint was a chronic post-traumatic wound of unspecified duration on the left foot as a result of being knocked by a car. He denied any

Isolate characterization

Following the inconclusive isolate identification results further taxonomic examination was done. The 1511 bp complete 16S rRNA gene of TV80 was amplified using D88 and E94 primers and sequenced using F16 and F17 primers as per previous description (Paster et al., 2001). The BLAST analysis on the NCBI web-site of the complete 16S rRNA gene provided 99.7%, 99.6% and 99.6% match with A. animicus (NR_117615), A. xylosoxidans (CP014065) and A. denitrificans (CP013923) respectively. Further

Discussion

Although multidrug-resistant non-fermenting bacteria have been implicated in causing wound infections (Bessa et al., 2015), information on the role of Achromobacter spp. in causing wound infections is limited. Achromobacter spp. have been previously described as environmental pathogens (Yabuuchi and Ohyama, 1971). The recent increasing rate of isolating them from human clinical samples warrants clinicians awareness due to treatment challenges posed by their antimicrobial resistance profiles (

Conclusion

This case report describes challenges in identification of A. animicus especially in LICs. It also for the first time highlights A. animicus role in causing wound infections; the information which is important to clinicians and clinical microbiologists. There is a need to improve the microbiological services in LICs in order to identify uncommon human pathogens. This information will assist in updating the database of automated identification systems such as MALDI-TOF based systems by adding

Limitations

A possible limitation regarding the causal link to the etiological agent may arise from the fact that under the field setting it was only possible to take a wound swab and not a tissue biopsy, which is a sample of higher value. However, the consecutive gram strain from the second swab yielded gram-negative rods. Furthermore, growth upon primary culture was pure and massive. Treatment according to the resistance profile led to the initial improvement.

A second limitation is that anaerobic culture

Conflict of Interests

The authors declare no competing interests.

Consent

Informed assent was obtained from the patient for participating in a wound care research project. Written consent for publication of this case report and accompanying images was obtained from Mwanza city social welfare department. In addition, the ethical clearance number 075/2015 was provided by CUHAS/BMC ethics review board to conduct this research. Written consent and clearance copies are available for review by the Editor-in-Chief of this journal when required.

Funding

This study was supported by CUHAS and German Academic Exchange Service (DAAD) research funds to NM and a grant for wound care project from Bisou Bailey Foundation (Ca, USA) to MH. Identification and molecular analysis of this isolate was supported by the Institute of Hygiene and Microbiology of Wuerzburg, Germany.

Acknowledgments

The authors are grateful to Vitus Silago of the CUHAS laboratory for the technical assistance and the Tanzania Rural Health Movement volunteers involved in wound care. Heartfelt thanks goes to the management of Uhuru hospital in Tanzania for their free of charge wound dressing of the child on days out of the Wound Care Project schedule. Authors also thank DNA laboratory technicians of the Institute of Hygiene and Microbiology Wuerzburg, Germany for their excellent technical assistance.

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