TABLE 2.
Susceptibility of Isolates from Urine Cultures of Children Seen in a Pediatric Emergency Departmenta
| Isolate and Variable | Amoxicillin–ampicillin | Amoxicillin–clavulanate | Cephalexin | Gentamicin | Nitrofurantoin | Trimethoprim– sulfamethoxazole | Ceftriaxone | Cefixime | Cefazolinb | Ciprofloxacin | Tobramycin | Carbapenemsb,c |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Escherichia coli (n = 135)c,d | ||||||||||||
| No. of patients/cultures | 135 | 135 | 135 | 135 | 135 | 135 | 9e | 3e | 10e | 3e | 5e | 1e |
| Susceptible | 63% | 7% | 97% | 97% | 99% | 78% | 100% | 67% | 0% | 100% | 20% | 100% |
| Resistant | 37% | 8% | 3% | 3% | 1% | 22% | 0% | 33% | 100% | 0% | 0% | 0% |
| Intermediate resistance | 0% | 5% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 80% | 0% |
|
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| Proteus mirabilis (n = 8) | ||||||||||||
| No. of patients/cultures | 8 | – | 8 | 8 | 8 | 8 | 1 | – | 1 | – | – | – |
| Susceptible | 100% | – | 100% | 100% | 12% | 100% | 100% | – | 0% | – | – | – |
| Resistant | 0% | – | 0% | 0% | 88% | 0% | 0% | – | 100% | – | – | – |
| Intermediate resistance | 0% | – | 0% | 0% | 0% | 0% | 0% | – | – | – | – | – |
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| Klebsiella pneumoniae (n = 7)d | ||||||||||||
| No. of patients/cultures | 6 | 6 | 6 | 6 | 6 | 5 | – | – | – | 3 | – | – |
| Susceptible | 0% | 100% | 100% | 100% | 17% | 100% | – | – | – | 100% | – | – |
| Resistant | 100% | 0% | 0% | 0% | 0% | 0% | – | – | – | 0% | – | – |
| Intermediate resistance | 0% | 0% | 0% | 0% | 83% | 0% | – | – | – | 0% | – | – |
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| Citrobacter sp. (n = 3) | ||||||||||||
| No. of patients/cultures | 3 | 3 | 3 | 3 | 3 | 3 | – | – | 2 | – | – | – |
| Susceptible | 0% | 33% | 33% | 100% | 67% | 100% | – | – | 0% | – | – | – |
| Resistant | 100% | 67% | 67% | 0% | 33% | 0% | – | – | 100% | – | – | – |
| Intermediate resistance | 0% | 0% | 0% | 0% | 0% | 0% | – | – | 0% | – | – | – |
|
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| Enterococcus faecalis (n = 6)d | ||||||||||||
| No. of patients/cultures | 6 | – | – | – | 6 | – | – | – | – | – | – | – |
| Susceptible | 100% | – | – | – | 100% | – | – | – | – | – | – | – |
| Resistant | 0% | – | – | – | 0% | – | – | – | – | – | – | – |
| Intermediate resistance | 0% | – | – | – | 0% | – | – | – | – | – | – | – |
CFU = colony-forming unit, MIC = minimum inhibitory concentration, UTI = urinary tract infection.
Two patients had 2 organisms each. In addition, the table includes results for 3 patients who did not meet the study definition of a positive urine culture result. Other organisms: Klebsiella oxytoca (n = 2), Staphylococcus aureus (n = 1), coagulase-negative Staphylococcus (n = 5), Streptococcus agalactiae (n = 4), Aerococcus urinae (n = 1), Enterococcus faecium (ampicillin sensitive) (n = 1), Staphylococcus saprophyticus (n = 2).
Six of the 10 E. coli cultures with cefazolin resistance had concurrent cephalexin susceptibility. Cefazolin is used as a surrogate for cephalexin and when used specifically for lower UTI has a higher MIC breakpoint (≤ 16 μg/mL) than when it is used for any infection other than lower UTI (for which MIC breakpoint is ≤ 2 μg/mL).7 Therefore, in cases where the bacteria is reported as resistant to cefazolin but susceptible to cephalexin, cephalexin can be used for lower UTIs, but there is uncertainty as to whether cefazolin or cephalexin should be used for upper UTIs.
One isolate had extended-spectrum β-lactamase (ESBL) resistance.
Two cultures had 2 organisms with more than 107 CFU/L: E. coli and E. faecalis in combination; E. coli and K. pneumoniae in combination.
Only reported according to local microbiology lab algorithm based on resistance or clinician request.