Mobile phones in the orthopedic operating room: Microbial colonization and antimicrobial resistance

Table 1 Results of bacterial culture and colony counts

Organism	Cell phones (n)1	Colony count, n (%)
		Low	Medium	High
Coagulase-negative Staphylococcus	62	58 (93.5)	3 (4.9)	1 (1.6)
Micrococcus	41	41 (100)	0	0
Bacillus	26	26 (100)	0	0
Pseudomonas species	10	10 (100)	0	0
Fungi	6	6 (100)	0	0
Corynebacterium	5	4 (80)	0	1 (20)
Streptococcus species	4	4 (100)	0	0
Enterobacter	3	0	1 (33.3)	2 (66.7)
Acinetobacter	2	0	1 (50)	1 (50)
Klebsiella	1	1 (100)	0	0
Pseudomonas aeruginosa	1	1 (100)	0	0
E. coli	1	1 (100)	0	0

¹44% of mobile phones harbored more than 1 organism.

Table 2 Antibiotic resistance analysis

Coagulase-negative Staphylococcus (n = 62)		Enterobacter (n = 3)		Pseudomonas species (n = 10)
Drug	Resistant (%)	Drug	Resistant (%)	Drug	Resistant (%)
Clindamycin	26 (41.3)	Augmentin	3 (100)	Augmentin	9 (90)
Erythromycin	40 (63.5)	Gentamycin	0	Amikacin	1 (10)
Levofloxacin	15 (23.8)	Ceftriaxone	3 (100)	Aztreonam	10 (100)
Penicillin	62 (98.4)	Ciprofloxacin	3 (100)	Imipenem	9 (90)
Clotrimazole	19 (29.7)	Tetramycin	3 (100)	Piptazobactam	0
Tetramycin	12 (19.0)	Meropenem	3 (100)	Gentamycin	0
Oxacillin	34 (54.0)			Ceftriaxone	10 (100)
				Tetramycin	1 (10)
				Ciprofloxacin	3 (30)
				Meropenem	8 (80)

Table 3 Factors affecting bacterial colonization of cell phones

Variable	Total	Bacterial colonization present, n (%)	P value
Specialty
Orthopedics	43	39 (90.7)	1.000
Anesthesia	42	39 (92.9)
Appointment1
Surgeon	22	21 (95.5)	1.000
Resident	30	27 (90)	0.425
Technician	33	30 (90.9)	0.681
Nursing	15	15 (100)	0.590
Age group (yr)			1.000
≤ 30	52	48 (92.3)
> 30	48	45 (93.8)
Gender
Male	81	75 (92.6)	1.000
Female	19	18 (94.7)
Type of cell phone
Smart phone	93	86 (92.5)	1.000
Basic	7	7 (100)
Mobile cover
Present	67	65 (97)	0.038
Absent	33	28 (84.8)
Keypad
Present	10	10 (100)	1.000
Absent	90	83 (92.2)
Cracked screen
Yes	42	42 (100)	0.020
No	58	51 (87.9)
Cell phone cleaning
Yes	55	48 (87.3)	0.040
No	45	45 (100)
Duration since last cell phone cleaning
< 24 h	33	26 (78.8)	0.034
> 24 h	22	22 (100)
Duration since last hand wash
< 10 min	46	44 (95.7)	0.666
≥ 10 min	42	39 (92.9)

¹Each category was tested against all others.

Table 4 Demographic/job related and cell phone related factors for Coagulase-negative Staphylococcus species

Variable	Colonized cell phones (%)	Crude odds ratio	P value	Adjusted odds ratio	P value
Demographic/job related factors
Orthopedic surgeon			0.067		0.085
No	58.4	1		1
Yes	90.9	7.12 (0.87, 58.01)		6.47 (0.77, 54.15)
Anesthesia consultant			0.906
No	63.6	1
Yes	55	0.91 (0.30, 3.97)
Orthopedic residents			0.332
No	51	1
Yes	73.3	1.83 (0.54, 6.23)
Anesthesia resident			0.455
No	63.5	1
Yes	53.3	0.66 (0.22, 1.98)
Orthopedic technician			0.185		0.241
No	59	1		1
Yes	76.5	2.26 (0.68, 7.51)		2.10 (0.61, 7.28)
Anesthesia technician			0.009		0.043
No	67.9	1		1
Yes	31.3	0.22 (0.07, 0.68)		0.29 (0.09, 0.96)
Nursing staff			0.455
No	63.5	1
Yes	53.3	1.52 (0.50, 4.61)
Gender			0.682
Female	57.9	1
Male	63	1.24 (0.45, 3.42)
Age (yr)			0.951
< 30		1
30-50		0.78 (0.17, 3.58)
≥ 50		0.82 (0.18, 3.65)
Cell phone related factors
Type of cell phone			0.290
Basic phone	42.9	1
Smart phone	63.4	2.31 (0.49, 10.96)
Mobile cover			0.001		0.004
No	39.4	1		1
Yes	73.1	4.19 (1.73, 10.13)		8.31 (1.95, 35.40)
Keypad			0.414
No	63.3	1
Yes	50	1.73 (0.47, 6.41)
Cracked screen			0.395
No	65.5	1
Yes	57.1	0.70 (0.31, 1.59)
Cleans their cell phone			0.601
No	60	1
Yes	65.5	1.26 (0.53, 3.03)
Duration since last cell phone cleaning			0.013		0.032
< 24 h	51.5	1		1
≥ 24 h	86.4	5.82 (1.46, 23.17)		5.30 (1.16, 24.34)