Antimicrobial susceptibilities of selected pathogens, 2001 / Georgia Public Health

Campylobacter spp.* * (One weekly isolate from stewide convenience sample tested at CDC). Salmonella spp. (non-typhoidal) (~10% sample of statewide isolates tested at CDC). Shigella sonnei (All available statewide isolates tested at GPHL). Shigella flexneri (All available statewide isolates tested at GPHL). E. coli O157 (All available statewide isolates tested at CDC). Streptococcus pneumoniae (All invasive isolates from Atlanta (20-cty) MSA tested at CDC). Mycobacterium tuberculosis (All statewide isolates tested at GPHL).

Antimicrobial Susceptibilities of Selected Pathogens, 2001

B-lactam antibiotics

Number tested

53

185

406

47

27

665

428

Total isolates

640

1721

629

70

45

746

452

Percent Tested (%)

8

11

65

67

60

89

95

% Susceptible

amoxicillin

89

amoxicillin-clavulanic acid

98

47

26

100

ampicillin

87

4

15

96

cefotaxime

83

cefoxitin

>99

100

ceftiofur

>99

100

ceftriaxone

>99

>99

100

100

cefuroxime sodium

72

cephalothin

>99

32

81

100

imipenem

100

100

meropenem

78

penicillin

68

azithromycin

96

erythromycin

96

73

nalidixic acid

74

99

>99

96

ciprofloxacin

74

100

>99

98

100

levofloxacin

99

amikacin

100

100

gentamicin chloramphenicol clindamycin

100

98

>99

98

100

100

90

96

32

100

96

96

94

apramycin

100

100

kanamycin

94

100

streptomycin

83

58

2

100

tetracycline

66

82

79

9

90

sulfamethoxazole

85

79

45

100

trimethoprim/sulfamethoxazole

98

83

60

100

62

vancomycin

100

ethambutol

99

isoniazid

94

rifampin

>99

99

other antibiotics

Trends, Comments and Other Pathogens

Campylobacter Susceptibilities were determined using 2001 NCCLS breakpoints for Enterobacteriaceae. Erythromycin susceptible: MIC < 4

spp.

g/ml.

Salmonella spp. Antimicrobial treatment for enteric salmonellosis generally is not recommended.
Antimicrobial resistance in S. sonnei is dynamic. In 2000, nearly half of isolates were resistant to trimethoprimShigella sonnei sulfamethoxazole (SXT). In 2001 this changed, with large outbreaks among children caused by a strain with SXT-
susceptibility.

Shigella flexneri E. coli O157

S. flexneri has been associated with outbreaks among men who have sex with men. Use of antimicrobials is controversial for enteritis caused by E. col i O157. Several studies have shown no symptomatic improvement and increased risk for hemolytic-uremic syndrome among treated patients (Guerrant RL et. al. Clin Infect Dis 2001; 32:331-51).

Streptococcus Pneumoniae

NCCLS 2001 MIC interpretive standards for S. pneumoniae were used for all antimicrobials. For penicillin, 16% (109/665) had intermediate susceptibility and 16% (106/665) were resistant (penicillin MIC breakpoints: susceptible <0.06 g/ml, intermediate 0.12-1 g/ml, resistant >2 g/ml). For amoxicillin, 6% (37/665) were intermediate and 5% (34/665) were resistant (amoxicillin MIC breakpoints: susceptible <2 g/ml, intermediate 4 g/ml, resistant >8 g/ml). For cefuroxime, <1% (1/665) were intermediate and 28% (184/665) were resistant (cefuroxime MIC breakpoints: susceptible <0.5 g/ml, intermediate 1 g/ml, resistant >2 g/ml). For cefotaxime, 14% (94/665) were intermediate and 3% (22/665) were resistant (cefotaxime MIC breakpoints: susceptible <0.5 g/ml, intermediate 1 g/ml, resistant >2 g/ml). For meropenem, 10% (68/665) were intermediate and 12% (78/665) were resistant (meropenem MIC breakpoints: susceptible <0.25 g/ml, intermediate 0.5 g/ml, resistant >1 g/ml). Five isolates (<1%) were resistant to levofloxacin. All isolates were susceptible to vancomycin.

Mycobacterium 6% (27/427) were INH-resistant. Two cases of multidrug-resistant TB (resistant to at least INH and rifampin) were identified, tuberculosis both among foreign-born persons.