Causative bacteria of ventilator-associated pneumonia in intensive care unit in Bahrain: Prevalence and antibiotics susceptibility pattern

Table 1 The clinical pulmonary infection score

Assessed parameter	Result	Score
Temperature (°Celsius)	36.5–38.4 °C	0
	38.5–38.9 °C	1
	≤ 36 or ≥ 39 °C	2
Leukocytes in blood (cells/mm3)	4000–11000/mm3	0
	< 4000 or > 11000/mm3	1
	≥ 500 band cells	2
Tracheal secretions (subjective visual scale)	None	0
	Mild/non-purulent	1
	Purulent	2
Radiographic findings (on chest radiography, excluding CHF and ARDS)	No infiltrate	0
	Diff use/patchy infiltrate	1
	Localized infiltrate	2
Culture results (endotracheal aspirate)	No or mild growth	0
	Moderate or florid growth	1
	Moderate or florid growth and pathogen consistent with gram stain	2
Oxygenation status	> 240 or ARDS	1
	≤ 240 and absence of ARDS	2

CHF: Congestive heart failure; ARDS: Acute respiratory distress syndrome.

Table 2 Comparison between ventilator-associated pneumonia and non-ventilator-associated pneumonia groups for risk factors and complications, n (%)

Risk factors and complications		VAP group, n = 46	Non-VAP group, n = 109	P value
Age, mean ± SD		52.74 ± 20.42	61.45 ± 65.05	> 0.5
Sex, males%		32 (69.57)	73 (66.97)	> 0.5
Number of hospital days before intubation, mean ± SD		5.39 ± 8.11	3.38 ± 6.37	> 0.5
Number of ICU days before intubation, mean ± SD		0.52 ± 1.94	0.47 ± 2.78	> 0.5
Presence of comorbidities	Diabetes mellitus	19 (41.30)	54 (49.54)	> 0.5
	Hypertension	19 (41.30)	67 (61.47)	> 0.5
	Chronic kidney disease	7 (15.22)	28 (25.69)	> 0.5
	Ischemic heart disease	6 (13.04)	25 (22.94)	> 0.5
	Neurological disorder	5 (10.87)	9 (8.26)	> 0.5
	Malignancy	4 (8.70)	3 (2.75)	> 0.5
	Liver disease	3 (6.52)	8 (7.34)	> 0.5
	Sickle cell disease	3 (6.52)	3 (2.75)	> 0.5
Hospital course	Length of ICU stay, mean ± SD	21.41 ± 11.89	11.01 ± 10.38	< 0.001a
	Duration of mechanical ventilation, mean ± SD	16.67 ± 8.70	12.03 ± 10.53	0.009a
	Extubation	18 (39.13)	79 (72.48)	< 0.001a
	Need of re-intubation	12 (26.09)	11 (10.09)	0.014a
	Tracheostomy	14 (30.43)	9 (8.26)	< 0.001a
Potential complication	Septic shock	28 (60.87)	31 (28.44)	< 0.001a
	ARDS	15 (32.61)	12 (11.01)	0.002a
	Acute kidney injury	24 (52.17)	36 (33.03)	0.031a
	Pneumothorax	1 (2.17)	2 (1.83)	> 0.5
	Mortality, deaths	14 (30.43)	21 (19.27)	> 0.5

^aMeans significant.

ARDS: Acute respiratory distress syndrome; VAP: Ventilator-associated pneumonia; ICU: Intensive care unit.

Table 3 Most common organisms isolated among patients with ventilator-associated pneumonia, n (%)

Organism	Total	Early-onset VAP (Number 9)		Late-onset VAP (Number 37)
		Number (of total)	MDR	Number (of total)	MDR
Total gram negative	38 (82.6)	8 (21)	6 (75)	30 (79)	21 (70)
Acinetobacter baumannii	19 (50)	4 (21)	4 (100)	15 (79)	14 (93)
Klebsiella pneumoniae	8 (21.1)	3 (37.5)	2 (66.6)	5 (62.5)	5 (100)
Pseudomonas aeruginosa	3 (9)	0	0	3 (100)	1 (33.3)
Stenotrophomonas maltophilia	5 (13.1)	0	0	5 (100)	0
Enterobacter asburiae	1 (2.6)	1 (100)	0	0	0
E coli	1 (2.6)	0	0	1	1 ESBL (100)
Hemophilus influenzae	1 (2.6)	0	0	1 (100)	0
Total gram positive	5 (11)	0	0	5 (100)
Staph aureus	4 (80)	0	0	4 (100)	0
MRSA	1 (20)	0	0	1 (100)	0
	0	0	0	0	0
	0	0	0	0	0
Fungal infection
Candida species	3 (100)	1 (33.3)	0	2 (66.6)	0
Total microorganisms	46 (100)	9 (19.6)	6 (13)	37 (80.4)

VAP: Ventilator-associated pneumonia; MDR: Multidrug-resistant; ESBL: Extended spectrum beta-lactamase; MRSA: Methicillin-resistant staphylococcus aureus.

Table 4 Antibiotics sensitivity percentage of the common gram-positive causative organisms for patients with ventilator-associated pneumonia in our study, n (%)

Antimicrobial agent	MSSA, n = 4	MRSA, n = 1
Penicillin	0/4 = 0 (0)	0/1 = 0 (0)
Oxacillin	4 (100)	0/1 = 0 (0)
Erythromycin	4 (100)	1 (100)
Clindamycin	4 (100)	1 (100)
Tetracycline	4 (100)	1 (100)
Vancomycin	4 (100)	1 (100)

MSSA: Methicillin-sensitive staphylococcus aureus, MRSA: Methicillin-resistant staphylococcus aureus.

Table 5 Antibiotics sensitivity percentage of the common gram-negative causative organisms for ventilator-associated pneumonia in our study, n (%)

Antimicrobial agent	Acinetobacter baumannii	Klebsiella pneumoniae	Stenotrophomonas maltophilia	Pseudomonas aeruginosa
Number of organisms	19 (50)	8 (42)	5 (26)	3 (16)
Ceftazidime	1 (5.2)	0	1 (20)	3 (100)
Trimethoprim/sulfamethoxazole	7 (37)	4 (50)	5 (100)	-
Levofloxacin	0	1 (12.5)	5 (100)	-
Minocycline	-	-	5 (100)	-
Piperacillin-tazobactam	1 (5.2)	0	-	3 (100)
Cefepime	1 (5.2)	1 (12.5)	-	3 (100)
Meropenem	1 (5.2)	1 (12.5)	-	2 (66.6)
Imipenem	1 (5.2)	1 (12.5)	-	2 (66.6)
Ertapenem	1 (5.2)	1 (12.5)	-	2 (66.6)
Colistin	19 (100)	5 (62.5)	-	3 (100)
Gentamicin	7 (37)	3 (37.5)	-	3 (100)
Amikacin	7 (37)	3 (37.5)	-	3 (100)
Ciprofloxacin	1 (5.2)	1 (12.5)	-	3 (100)
Tigecycline	4 (21)	7 (87.5)	-	-
Ampicillin	-	-	-	-
Amoxiclav	-	1 (12.5)	-	-
Cefuroxime	-	1 (12.5)	-	-
Ceftriaxone	-	1 (12.5)	-	-