Differences in Microbial Spectrum and Antibiotic Resistance between Old and Old-Aged People with Infected Diabetic Foot Syndrome (DFS)

Department of Endocrinology, Diabetology and Geriatrics, Stuttgart General Hospital, Prießnitzweg 24, 70374 Stuttgart, Germany

^*Corresponding Author: Dörr S, Department of Endocrinology, Diabetology and Geriatrics, Stuttgart General Hospital, Prießnitzweg 24, 70374 Stuttgart, Germany, E-mail: s.Dö[email protected]

Received : September 10, 2019
Published : October 10, 2019

ABSTRACT

Introduction: Due to a rising life expectancy and an improvement in diabetes treatment all health care professionals are faced with an increasing number of elderly with diabetes. About one quarter of diabetic patients will suffer from diabetic foot syndrome at least once in their lifetime and often amputation is necessary within the next 4 years. Early start of a targeted and effective antibiotic treatment based on the most common germs and their antibiotic resistance is therefore essential to save feet. Are there differences in detected bacterial strains between older and aged people with infected DFS?

Method and Materials: Identifying all geriatric patients treated due to infected DFS between October 2018 and March 2019 and recording every detected germ with its resistance properties. Descriptively presentation of results in two groups (age ≤ 70 and > 70 years).

Results: 177 cases and 514 germs could be identified with a median age of 71 years and a proportion of 77% men. In both groups gram-positive germs form the majority with about 60%. With increase of age a slight increase of gram-negative germs, especially Pseudomonas aeruginosa (PSA), could be detected (+ 1.4%). Staphylococcus aureus (SAU) was the most common gram-positive germ (20%) in both groups. There was a high resistance rate against benzyl- and aminopenicillins without inhibitor of β-lactamase (β-LI) of about 62 and 77% respectively. PSA showed increase of resistance against Piperacillin (+ 17%), Piperacillin/Tazobactam (+ 8.7%) and Ceftazidime (+ 8.7%), whilst those against Imipenem and Meropenem decreased (- 15.9%) with increase of age. None of the isolated PSA strains showed Gentamicin or Cefipime resistance. Resistance of gram-negative germs against Piperacillin/Tazobactam, third generation Cephalosporins, Meropenem and Gentamicin were below 10% and even decreased with increase of age.

Conclusion: Regardless of age the majority of infected DFU are caused by gram-positive germs. Because of high resistance rates against penicillin without β-LI in gram-positive germs, Penicillin should always be combined with β-LI. When gram-negative germs are suspected Piperacillin/Tazobactam or Meropenem are appropriate and effective treatment options, although resistance rates in PSA might be higher with increase of age.

Keywords: Diabetic foot syndrome; Antibiotic resistance