Frequency and antimicrobial susceptibility of bacterial agents causing peritoneal dialysis-peritonitis in a Brazilian single center over 20 years

Figures & data

Figure 1. Temporal distribution of bacterial causative organisms of peritoneal dialysis-related peritonitis in a Brazilian center over two decades. Left axis (columns) represents the proportion (percentage) of each bacterial group, according to the 3-year periods evaluated. Right axis (line) indicates the overall number of isolates in each of the same 3-year periods. Changes in peritoneal dialysis practice are named above the bars, as well as the year of their implementation. APD: automated peritoneal dialysis; CoNS: coagulase-negative Staphylococcus; GNB: gram-negative bacilli.

Table 1. Causative agents of 400 episodes of peritoneal dialysis-associated peritonitis caused by bacterial agents in a Brazilian healthcare center (1993–2013)

Species	Frequency	Rate (%)
Staphylococcus spp.	263	65.75
S. aureus	85	21.25
S. epidermidis	91	22.75
Other coagulase-negative Staphylococcus^a	87	21.75
Gram-negative bacilli	137	34.25
Enterobacteriaceae^b	81	20.25
P. aeruginosa	27	6.75
Acinetobacter spp.	14	3.5
Other non-fermentative gram-negative bacilli^c	15	3.75

^a S. hominis, S. warneri, S. haemolyticus, S. xylosus, S. lugdunensis, S. simulans and S. cohnii.

^b Enterobacter spp., Klebsiella spp., E. coli, and Serratia spp.

^c S. maltophilia, B. cepacia, A. xylosoxidans; P. fluorescens.

Table 2. Susceptibility parameters of causative agents of PD-related peritonitis in a single healthcare center (Botucatu Medical School, 1993–2013)

Agent/antimicrobial drug (number of evaluated strains)	MIC range (μg/mL)	MIC50 (μg/mL)	MIC90 (μg/mL)	Susceptibility rate (%)
S. aureus (85)
Penicillin G (85)	0.016–256	0.75	32	24.7
Oxacillin (85)	0.064–256	0.25	256	83.5
Cephalothin (85)	0.094–256	0.50	96	86.0
Levofloxacin (84)	0.020–256	0.25	0.38	84.7
Netilmicin (80)	0.064–24	0.19	6.0	90.6
Vancomycin (85)	0.25–2.0	1.0	1.5	100
Coagulase negative Staphylococcus (178)
Penicillin G (178)	0.006–256	0.50	32	22.5
Oxacillin (178)	0.016–256	0.75	256	36.0
Cephalothin (178)	0.016–256	0.50	2.0	93.8
Levofloxacin (63)	0.064–>32	0.38	24	64.6
Netilmicin (142)	0.016–32	0.38	6.0	75.3
Vancomycin (178)	0.125–3.0	1.5	2.0	100
Enterobacteriaceae (81)
Gentamicin (81)	0.012–>256	0.25	1.0	93.8
Ceftazidime (81)	0.32–256	0.125	1.5	95.1
Cefepime (81)	0.012–>32	0.047	0.38	92.6
Gatifloxacin (68)	0.04–>32	0.032	0.25	94.1
Ofloxacin (68)	0.023–>32	0.125	1.5	91.2
Imipenem (81)	0.023–2.0	0.250	1.0	96.3
P. aeruginosa (27)
Gentamicin (27)	0.038–>256	3.0	>256	70.4
Ceftazidime (27)	0.5–>256	1.5	192	74.1
Cefepime (27)	0.38–256	4.0	>32	66.7
Gatifloxacin (21)	0.094–>32	1.5	>32	66.7
Ofloxacin (21)	0.19–>32	3.0	>32	ND
Imipenem (27)	0.094–>32	1.5	>32	77.8
Acinetobacter spp. (14)
Gentamicin (14)	0.125–>256	2.0	>256	57.1
Ceftazidime (13)	0.75–>256	16	>256	46.2
Cefepime (14)	0.38–64	12	>32	42.9
Gatifloxacin (10)	0.023–16	0.5	8.0	50.0
Ofloxacin (10)	0.19–>32	3.0	>32	ND
Imipenem (14)	0.19–>32	0.5	>32	85.7

Notes: MIC50 and MIC90: The MIC values that can inhibit the growth of 50 and 90%, respectively, of the bacterial population.

Table 3. Distribution of resistance pattern classes [frequency (%)] of bacterial agents of peritoneal dialysis-associated peritonitis caused by bacterial agents in a Brazilian healthcare center (1993–2013)

Agent	Susceptible	Simple resistant	Multiple resistant	Total
Staphylococcus spp.	50 (19)	91 (35)	122 (46)	263 (100)
S. aureus	21 (25)	50 (59)	14 (17)	85 (100)
S. epidermidis	11 (12)	24 (26)	56 (62)	91 (100)
Other coagulase-negative Staphylococcus^a	18 (21)	17 (20)	52 (60)	87 (100)
Gram-negative bacilli	101 (74)	8 (6)	28 (20)	137 (100)
Enterobacteriaceae^b	68 (84)	5 (6)	8 (10)	81 (100)
P. aeruginosa	17 (63)	1 (4)	9 (33)	27 (100)
Acinetobacter spp.	5 (36)	0 (0)	9 (64)	14 (100)
Other non-fermentative gram-negative bacilli^c	11 (73)	2 (13)	2 (13)	15 (100)
Total	151 (38)	99 (25)	150 (37)	400 (100)

Notes: Susceptible: zero resistance; simple resistant: resistance to only one drug; multiple resistant: resistance to two or more drugs.

^a S. hominis, S. warneri, S. haemolyticus, S. xylosus, S. lugdunensis, S. simulans and S. cohnii.

^b Enterobacter spp., Klebsiella spp., E. coli, and Serratia spp.

^c S. maltophilia, B. cepacia, A. xylosoxidans; P. fluorescens.

Table 4. Distribution of susceptibility rates for the main antimicrobial agents in prevalent causative agents of peritoneal-dialysis bacterial related peritonitis S. aureus; coagulase negative Staphylococcus (CoNS); Enterobacteriaceae; P. aeruginosa; Acinetobacter spp.

Agent/antimicrobial	1993–1995	1996–1998	1999–2001	2002–2004	2005–2007	2008–2010	2011–2013
S. aureus (N = 85)	N = 0	N = 52	N = 16	N = 11	N = 1	N = 5	N = 0
Penicillin G	NT	33	13	0	0	40	NT
Oxacillin	NT	87	75	82	100	80	NT
Cephalotin	NT	87	81	82	100	100	NT
Vancomycin	NT	100	100	100	100	100	NT
CoNS (N = 178)	N = 52	N = 53	N = 19	N = 15	N = 8	N = 21	N = 10
Penicillin G	25	17	16	13	25	29	50
Oxacillin	40	38	32	13	25	29	70
Cephalotin	89	94	90	100	100	100	100
Vancomycin	100	100	100	100	100	100	100
Enterobacteriaceae (N = 81)	N = 0	N = 6	N = 21	N = 29	N = 14	N = 9	N = 2
Gentamicin	NT	100	100	97	93	67	100
Ceftazidime	NT	100	100	93	93	89	100
Cefepime	NT	100	100	97	93	56	100
Imipenem	NT	100	100	97	93	89	100
P. aeruginosa (N = 27)	N = 0	N = 0	N = 6	N = 7	N = 9	N = 3	N = 2
Gentamicin	NT	NT	83	86	44	67	100
Ceftazidime	NT	NT	100	86	44	67	100
Imipenem	NT	NT	100	86	44	100	100
Acinetobacter spp. (N = 14)	N = 0	N = 0	N = 3	N = 5	N = 2	N = 3	N = 1
Gentamicin	NT	NT	33	60	50	67	100
Ceftazidime	NT	NT	67	40	0	67	0
Imipenem	NT	NT	100	100	50	100	0

Note: NT–not tested.

Figure 2. Temporal evolution of resistant pattern categories and changes in peritoneal dialysis practice observed in peritoneal dialysis agents responsible for peritonitis.