Microbial Spectrum and Resistance Patterns in Ocular Infections: A 15-Year Review in East China

Figures & data

Table 1 Demographics and Clinical Characteristics

Variable		N (%)
Age	<10	345(9.8%)
	10–19	170(4.8%)
	20–29	532(15.1%)
	30–39	590(16.7%)
	40–49	645(18.3%)
	50–59	528(14.9%)
	60–69	372(10.5%)
	>70	265(7.5%)
	Unknown	86(2.4%)
Gender	Male	2512(71.1%)
	Female	935(26.5%)
	Unknown	86(2.4%)
Culture Location	Conjunctiva	1286(36.4%)
	Intraocular foreign body	934(26.4%)
	Vitreous humor	715(20.2%)
	Cornea	388(11.0%)
	Aqueous humor	210(5.9%)

Notes: %, percent of total; n, total number of isolates.

Table 2 Microbiological Spectrum of the Ocular Samples

Isolates	N	%Total
Gram positive	2916	82.5%
Coagulase-negative staphylococci	1888	53.4%
Staphylococcus aureus	381	10.8%
Streptococcus species	236	6.7%
Bacillus species	229	6.5%
Corynebacterium species	92	2.6%
Streptococcus pneumonia	60	1.7%
Other Gram-positive bacteria	30	0.8%
Gram negative	617	17.5%
Enterobacteriaceae	235	6.7%
Pseudomonas aeruginosa	126	3.6%
Other non-fermentative bacilli	205	5.8%
Neisseria	34	1.0%
Other Gram-negative bacteria	17	0.5%
Total	3533	100%

Notes: %, percent of total; N, number of isolates.

Table 3 Antibiotic Resistance Profiles for Isolates

Antibiotic		% (n)	X^2	P
Ciprofloxacin	MSCoNS	20.8(701)	140.4	≤0.0001
	MRCoNS	48.7(1125)
	MSSA	22.0(200)	31	≤0.0001
	MRSA	48.0(174)
Ofloxacin	MSCoNS	22.0(480)	43.9	≤0.0001
	MRCoNS	42.4(603)
	MSSA	15.5(142)	29.3	≤0.0001
	MRSA	46.4(139)
Levofloxacin	MSCoNS	10.5(418)	107.6	≤0.0001
	MRCoNS	39.2(769)
	MSSA	15.3(144)	9.2	0.002
	MRSA	31.4(105)
Chloramphenicol	MSCoNS	19.6(577)	30.9	≤0.0001
	MRCoNS	32.9(875)
	MSSA	14.7(163)	3.2	0.072
	MRSA	22.6(155)
Tobramycin	MSCoNS	24.8(436)	31.1	≤0.0001
	MRCoNS	38.9(545)
	MSSA	26.3(114)	0.9	0.351
	MRSA	41.0(122)
TMP-SMX	MSCoNS	40.3(528)	8.7	0.003
	MRCoNS	48.8(858)
	MSSA	32.3(129)	15.6	≤0.0001
	MRSA	57.6(118)
Moxifloxacin	MSCoNS	2.3(132)	17.7	≤0.0001
	MRCoNS	16.9(236)
	MSSA	6.5(31)	3.5	0.06
	MRSA	25.0(20)
Vancomycin	MSCoNS	0(701)	/	/
	MRCoNS	0(1125)
	MSSA	0(200)	/	/
	MRSA	0(174)

Notes: %, percent resistance; n, total number of isolates tested; Underlined values mean statistically significant at P < 0.05.

Abbreviations: MRCoNS, methicillin-resistant coagulase-negative staphylococci; MSCoNS, methicillin-susceptible coagulase-negative staphylococci; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus.

Table 4 Antibiotic Susceptibility Trends for Staphylococci from 2005 to 2020

P value*	S. aureus	CoNS
Levofloxacin	0.408	0.26
Chloramphenicol	0.553	≤0.001
Tobramycin	0.317	0.01
Methicillin	0.04	0.546

Notes: *χ² test for trend. Underlined values mean statistically significant at P < 0.05.

Abbreviations: S. aureus, Staphylococcus aureus; CoNS, coagulase-negative staphylococci.

Figure 1 Resistance to other antibiotic classes among isolates by methicillin resistance status. (A) Staphylococcus aureus. (B) Coagulase-negative staphylococci.

Abbreviations: MR, methicillin resistant; MS, methicillin susceptible.

Figure 2 Resistance among ocular isolates by patient age. Data are expressed as mean (SE) percentage of resistance (black line) and percentage of methicillin resistance (blue line) by decade of life. P values are calculated using analysis of variance of the mean percentage of resistance.

Figure 3 Antibiotic resistance trends over time. (A) Staphylococcus aureus. (B) Coagulase-negative staphylococci.