Multidrug-Resistant Bacteria Isolated from Blood Culture Samples in a Moroccan Tertiary Hospital: True Bacteremia or Contamination?

Figures & data

Figure 1 Flow chart of blood cultures received during this period.

Notes: *The prevalence and contamination rate with MDR bacteria were calculated by dividing the total number of true bacteremic episodes and contaminations by the total number of BCs received in the laboratory, respectively.

Table 1 Baseline Characteristics of Patients with Positive BCs with MDR Bacteria (True Bacteremia and Contaminations)

Characteristics	True Bacteremia (n = 157)	Contaminations (n = 9)	P-value
Age groups:
● < 1 month (n = 74)	67 (42.7%)	7 (77.8%)	0.079
● 1 month – 15 years (n = 36)	34 (21.7%)	2 (22.2%)	>0.99
● >15 years (n = 56)	56 (35.7%)	0 (0%)	0.029
Gender			0.490
● Male (n = 106)	99 (63.1%)	7 (77.8%)	-
● Female (n = 60)	58 (36.9%)	2 (22.2%)	-
Wards:
ICUs (n = 136)	129 (82.2%)	7 (77.8%)	0.666
● NICU	67 (51.9%)	7 (100%)	0.016
● PICU	22 (17.1%)	0 (0%)	0.598
● Adult ICU	40 (31%)	0 (0%)	0.105
Medical unit (n = 17)	15 (9.6%)	2 (22.2%)	0.231
Surgical unit (n = 3)	3 (1.9%)	0 (0%)	>0.99
Haemato-oncology (n = 10)	10 (6.4%)	0 (0%)	>0.99
Underlying conditions:
Age <1 month (n = 74)
● Prematurity (n = 51)	47 (70.1%)	4 (57.1%)	0.670
● GA <34 SA (n = 32)	31 (46.3%)	1 (14.3%)	0.131
● GA between 34–36 SA (n = 19)	16 (25%)	3 (42.9%)	0.363
Extreme ages (n = 83)	76 (48.4%)	7 (77.8%)	0.168
Prior hospitalization (n = 25)	23 (14.6%)	2 (22.2%)	0.626
Prior antibiotic therapy** (n = 22)	20 (12.7%)	2 (22.2%)	0.340
Long-term corticosteroid use (n = 7)	6 (3.8%)	1 (11.1%)	0.328
Chemotherapy (n = 10)	10 (6.4%)	0 (0%)	>0.99
Central line (n = 93)	93 (59.2%)	0 (0%)	0.000
Carriage of MDR*** (n = 6)	6 (3.8%)	0 (0%)	>0.99
Comorbidity*:
Age <1 month (n = 74)
● Neonatal pulmonary infection (n = 13)	11 (16.4%)	2 (28.6%)	0.599
● Neonatal pulmonary infection + prématurity (n = 26)	24 (35.8%)	2 (28.6%)	>0.99
● Neonatal respiratory distress (n = 5)	4 (6%)	1 (14.3%)	0.400
● Neonatal respiratory distress + prématurity (n = 20)	18 (26.9%)	2 (28.6%)	>0.99
● Perinatal asphyxia (n = 10)	8 (11.9%)	2 (28.6%)	0.238
● Jaundice (n = 8)	7 (10.4%)	1 (14.3%)	0.567
● Neonatal seizures (n = 5)	5 (7.5%)	0 (0%)	>0.99
● Congenital malformations (n = 7)	7 (10.4%)	0 (0%)	>0.99
● Ulcero-necrotizing enterocolitis (n = 4)	4 (6%)	0 (0%)	>0.99
Burns (n = 24)	24 (15.3%)	0 (0%)	0.360
Trauma (n = 14)	14 (8.9%)	0 (0%)	>0.99
Hematological malignancy (n = 10)	10 (6.4%)	0 (0%)	>0.99
Kidney disease (n = 11)	10 (6.4%)	1 (11.1%)	0.469
Post-surgery (n = 15) (cardiac, cranial, malformative, traumatic.)	15 (100%)	0 (0%)	>0.99
Others (n = 24)	23 (95.7%)	1 (11.1%)	>0.99
Presence of clinical signs of sepsis at the time of blood sampling (n = 157)	157 (100%)	0 (0%)	0.000
Laboratory parameters: median (interquartile range)
● White blood cells (G/L)	13.92 (0.11–56.27)	8.55 (8.43–12.63)	0.551
● ANC (G/L)	8.87 (0–53.8)	5.12 (1.99–7.71)	0.076
● Lymphocytes (G/L)	1.62 (0.05–7.23)	4.09 (0.71–5.61)	0.017
● Platelets (G/L)	129 (1–632)	246 (90–540)	0.038
● CRP (mg/L)	140.83 (31.29–492.10)	13.71 (3.72–30.69)	0.000
Median duration of antibiotic therapy (days)	10 (1–36)	8 (2 –12)	0.049
Median length of stay (days)	16 (2–90)	10 (2–20)	0.008
● ≤48h (n = 2)	1 (0.7%)	1 (11.1%)	0.114
● ] 48h-10 days] (n = 38)	33 (22.8%)	5 (55.6%)	0.041
● ] 10–21 days] (n = 58)	55 (37.9%)	3 (33.3%)	0.542
● >21 days (n = 154)	56 (100%)	0 (0%)	0.015
Overall mortality	61 (42.1%)	0 (0%)	0.009

Notes: *The association of more than one comorbidity is possible. **Previous antibiotic therapy (in the previous 3 months) could not be verified in all patients. ***Screening for MDR carriage was not systematically performed in all patients.

Abbreviations: ICUs, intensive care units; NICU, Neonatal ICU; PICU, pediatric ICU; GA, Gestational age; ANC, Absolute neutrophil counts.

Table 2 Distribution of the Main Monomicrobial and Polymicrobial Causative Agents (True Pathogens and Contaminants) in Positive BCs with MDR Bacteria

MDR Isolates (n=171)	True Bacteremia (n=157)	Contaminations (n=9)	P-value
Monomicrobial episode	152 (96.8%)	9 (100%)	>0.99
● ESBL-E (n=80)	77 (50.7%)	3 (33,3%)	0.495
o Klebsiella pneumoniae (n = 41)	38 (49.4%)	3 (100%)	–
o Enterobacter cloacae (n = 25)	25 (32.5%)	0 (0%)	–
o Escherichia coli (n = 10)	10 (13%)	0 (0%)	–
o Others* (n=4)	4 (5.2%)	0 (0%)	–
● CPE (n=51)	50 (32.9%)	1 (11.1%)	0.274
o Klebsiella pneumoniae (n = 34)	34 (68%)	0 (0%)	–
o Enterobacter cloacae (n = 10)	9 (18%)	1 ()	–
o Escherichia coli (n = 3)	3 (6%)	0 (0%)	–
o Others* (n= 4)	4 (8%)	0 (0%)	–
● CRPA (n=4)	3 (2%)	1 (11.1%)	0.207
● CRAB (n=20)	18 (11.8%)	2 (22.2%)	0.310
● MRSA (n=6)	4 (2.6%)	2 (22.2%)	0.037
Polymicrobial episode** (n=5)	5 (3.2%)	0 (0%)	>0.99
● CP-KP and CP-Citrobacter freundii	1 (20%)	0 (0%)	–
● CP-KP and CRAB	1 (20%)	0 (0%)	–
● ESBL-KP and ESBL-EK	1 (20%)	0 (0%)	–
● ESBL-KP and CP-EK	2 (40%)	0 (0%)	–
Other sites positive for the same isolates (n=65)	65 (41.7%)	0 (0%)	0.012
Nosocomial acquisition	149 (95.5%)	–	–

Notes: *ESBL-Enterobacter aerogenes (n = 2), ESBL-Citrobacter freundii (n = 1), ESBL-Proteus mirabilis (n = 1), CP-Enterobacter aerogenes (n = 1), CP-Klebsiella oxytoca (n = 2), CP-Serratia fonticola (n = 1). **Five polymicrobial BC positive for two MDR germs (9 MDR-Enterobacterales and 1 CRAB).

Abbreviations: ESBL-E, Extended-Spectrum Beta-Lactamase-producing Enterobacteriaceae; CPE, carbapenem-producing Enterobacteriaceae; CRAB, carbapenem-resistant Acinetobacter baumannii; CRPA, carbapenem-resistant Pseudomonas aeruginosa; MRSA, Methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant Enterococcus; KP, Klebsiella pneumoniae; EK, Enterobacter cloacae.

Table 3 Comparison of the Clinical Course of Patients According to the Appropriateness of Probabilistic Antibiotic Therapy

			Clinical Course Under Probabilistic Antibiotic Therapy			P-value
			Favourable	Unfavourable	Deceased
True bacteremia (n= 145)	Probabilistic antibiotic therapy	Appropriate (n=52)	29 (55.8%)	18 (34.6%)	5 (9.6%)	0.000
		Inappropriate (n=93)	0 (0%)	74 (79.6%)	19 (20.4%)
Contaminatio-ns (n=9)	Probabilistic antibiotic therapy	Appropriate (n=1)	1 (100%)	0 (0%)	0 (0%)	0.889
		Inappropriate (n=8)	7 (87.5%)	1 (12.5%)	0 (0%)