The Emergence of Reduced Ciprofloxacin Susceptibility in Salmonella enterica Causing Bloodstream Infections in Rural Ghana.
BACKGROUND
Salmonella ranks among the leading causes of bloodstream infections in sub-Saharan Africa. Multidrug resistant typhoidal and nontyphoidal Salmonella (NTS) isolates have been previously identified in this region. However, resistance to ciprofloxacin has rarely been reported in West Africa. This study aims to assess susceptibility against ciprofloxacin in Salmonella causing invasive bloodstream infections among children in rural Ghana.


METHODS
From May 2007 until May 2012, children attending a rural district hospital in central Ghana were eligible for recruitment. Salmonella enterica isolated from blood cultures were assessed for ciprofloxacin susceptibility by Etest (susceptible minimum inhibitory concentration [MIC] ≤ 0.06 µg/mL). The gyrA, gyrB, parC, and parE genes were sequenced to identify mutations associated with changes in susceptibility to fluoroquinolones.


RESULTS
Two hundred eighty-five Salmonella enterica isolates from 5211 blood cultures were most commonly identified as Salmonella enterica serovar Typhimurium (n = 129 [45%]), Salmonella enterica serovar Typhi (n = 89 [31%]), Salmonella enterica serovar Dublin (n = 20 [7%]), and Salmonella enterica serovar Enteritidis (n = 19 [7%]). All S. Typhi and S. Dublin were susceptible to ciprofloxacin. Reduced susceptibility (MIC >0.06 µg/mL) was found in 53% (10/19) of S. Enteritidis and in 2% (3/129) of S. Typhimurium isolates. Sequencing detected a single gyrB mutation (Glu466Asp) and a single gyrA mutation (Ser83Tyr) in all 3 S. Typhimurium isolates, while 9 of 10 S. Enteritidis harbored single gyrA mutations (Asp87Gly, Asp87Asn, or Asp87Tyr). No mutations were found in the parC and parE genes.


CONCLUSIONS
Ciprofloxacin susceptibility in invasive NTS in rural Ghana is highly dependent on serotype. Although reduced ciprofloxacin susceptibility is low in S. Typhimurium, more than half of all S. Enteritidis isolates are affected. Healthcare practitioners in Ghana should be aware of potential treatment failure in patients with invasive S. Enteritidis infections.
['Eibach|Daniel|D|', 'Al-Emran|Hassan M|HM|', 'Dekker|Denise Myriam|DM|', 'Krumkamp|Ralf|R|', 'Adu-Sarkodie|Yaw|Y|', 'Cruz Espinoza|Ligia Maria|LM|', 'Ehmen|Christa|C|', 'Boahen|Kennedy|K|', 'Heisig|Peter|P|', 'Im|Justin|J|', 'Jaeger|Anna|A|', 'von Kalckreuth|Vera|V|', 'Pak|Gi Deok|GD|', 'Panzner|Ursula|U|', 'Park|Se Eun|SE|', 'Reinhardt|Alexander|A|', 'Sarpong|Nimako|N|', 'Schütt-Gerowitt|Heidi|H|', 'Wierzba|Thomas F|TF|', 'Marks|Florian|F|', 'May|Jürgen|J|']
D000900:Anti-Bacterial Agents D016470:Bacteremia D002675:Child, Preschool D002939:Ciprofloxacin D024901:Drug Resistance, Multiple, Bacterial D005260:Female D005869:Ghana D006801:Humans D007223:Infant D008297:Male D008826:Microbial Sensitivity Tests D011446:Prospective Studies D012480:Salmonella Infections D019779:Salmonella enterica
susceptibility Salmonella Ghana Africa multidrug resistant