Table S1. the Documentation Rate of Reasons for Antimicrobial Drug Use

Table S1. The documentation rate of reasons for antimicrobial drug use. Reasonsa Total Site A Site B Any reasons 232/327 (70.9%) 53/79 (67.1%) 179/248 (72.2%) Treatment of infection 138/163 (84.7%) 37/43 (86.0%) 101/120 (84.2%) Prophylaxis Surgical 76/101 (75.2%) 14/28 (50.0%) 62/73 (84.9%) Medical 18/46 (39.1%) 2/5 (40.0%) 16/41 (39.0%) Non-infectious reasons 0/3 (0.0%) 0/1 (0.0%) 0/2 (0.0%) Unknown reasons 0/14 (0.0%) 0/2 (0.0%) 0/12 (0.0%) aInvestigators speculated the reasons for antimicrobial drug use by reviewing the medical electronic records when the reasons were not documented in medical records.

Table S2. Clinical and demographic characteristics of surveyed patients according to the different sitesa. Total Site A Site B Characteristics N = 820 N = 256 N = 564 Age, yr, median (IQR) 70 (55 – 80) 76 (67 – 84) 68 (48 – 77) Age category < 1 year 34 (4.2) 2 (0.8) 32 (5.7) 1 – 17 year 30 (3.7) 11 (4.3) 19 (3.4) 18 – 24 year 10 (1.2) 1 (0.4) 9 (1.6) 25 – 44 year 74 (9.0) 12 (4.7) 62 (11.0) 45 – 64 year 160 (19.5) 33 (12.9) 127 (22.5) 65 – 84 year 415 (50.6) 142 (55.5) 273 (48.4) > 84 year 97 (11.8) 55 (21.5) 42 (7.5) Women 380 (46.3) 131 (51.2) 249 (44.2) Residence before the index admissionb Home 747 (91.1) 230 (89.8) 517 (91.7) Nursing care facility 27 (3.3) 14 (5.5) 13 (2.3) Other hospitals 23 (2.8) 12 (4.7) 11 (2.0) Past medical history Ischaemic heart disease 57 (7.0) 16 (6.3) 41 (7.3) Stroke 89 (10.9) 34 (13.3) 55 (9.8) Dementia 39 (4.8) 21 (8.2) 18 (3.2) Liver cirrhosis 19 (2.3) 8 (3.1) 11 (2.0) Diabetes mellitus 150 (18.3) 47 (18.4) 103 (18.3) Dialysis 26 (3.2) 0 (0.0) 26 (4.6) Immunosuppression drug use 107 (13.1) 23 (9.0) 84 (14.9) Location in hospitals Ward 777 (94.8) 247 (96.5) 530 (94.0) Critical care unit 43 (5.2) 9 (3.5) 34 (6.0) Central line in place on survey date Any 54 (6.6) 17 (6.6) 37 (6.6) Peripherally inserted 4 (0.5) 0 (0.0) 4 (0.7) Peripheral line in place on survey date 284 (34.6) 88 (34.4) 196 (34.8) Urinary catheter in place on survey date 121 (14.8) 33 (12.9) 88 (15.6) Intubated or tracheal tube in place on survey date 25 (3.1) 2 (0.8) 23 (4.1) Drainage tube in place on survey date 49 (6.0) 6 (2.3) 43 (7.6) 3

Median days to survey date from admission (IQR) 9 (3 – 23) 9 (3 – 22) 8 (3 – 23) aValues are the number of patients, with percentage of the total patients in parenthesis according to the survey site. bTwenty-three patients who were born in site B were excluded. 4

Table S3. Prevalence of antimicrobial drug use according to different specialties. Specialty Number of patients Prevalence, % (95% CI)a Total 820 33.5 (30.3 – 36.8) Site A 256 28.5 (23.0 – 34.1) Site B 564 35.8 (31.9 – 39.8) General surgery 144 34.0 (26.2 – 41.8) Site A 53 30.2 (17.4 – 43.0) Site B 91 36.4 (26.2 – 46.3) Orthopaedic surgery 91 24.2 (15.2 – 33.1) Site A 46 17.4 (6.0 – 28.8) Site B 45 31.1 (17.0 – 45.2) Neurosurgery 39 28.2 (13.4 – 43.0) Site A 23 30.4 (10.1 – 50.8) Site B 16 25.0 Cardiac surgery 20 45.0 (21.1 – 68.9) Site A 0 NA Site B 20 45.0 (21.1 – 68.9) Gynaecology 63 36.5 (24.2 – 48.7) Site A 4 25.0 Site B 59 37.3 (24.6 – 50.0) Oral and maxillofacial surgery 13 76.9 Site A 13 76.9 Site B 0 NA Otorhinolaryngology 22 36.4 (14.5 – 58.2) Site A 5 60.0 Site B 17 29.4 Ophthalmology 15 86.7 Site A 0 NA Site B 15 86.7 Urology 43 41.9 (26.5 – 57.2) Site A 13 23.1 Site B 30 50.0 (31.0 – 69.0) Dermatology 4 25.0 Site A 4 25.0 Site B 0 NA Internal medicine 301 26.9 (21.9 – 31.9) 5

Site A 90 23.3 (14.4 – 32.2) Site B 211 28.4 (22.3 – 34.6) Haematology 19 78.9 Site A 0 NA Site B 19 78.9 Paediatrics 43 30.3 (15.9 – 44.5) Site A 5 60.0 Site B 38 26.3 (11.6 – 41.0) aThe 95% confidence intervals were not calculated if the number of patients was less than 20. CI, confidence interval; NA, not available.

Table S4. Groups of antimicrobial drugsa representing more than one percent of antimicrobial drugs given to surveyed patientsb. Type Total Site A Site B All antimicrobial drugs 327 (100.0) 79 (100.0) 248 (100.0) First-generation cephalosporins 71 (21.7) 20 (25.3) 51 (20.6) Cefazolin 70 (21.4) 19 (24.1) 51 (20.6) Cefalexin 1 (0.3) 1 (1.3) 0 (0.0) Third-generation cephalosporins 44 (13.5) 15 (19.0) 29 (11.7) Ceftriaxone 30 (9.2) 11 (13.9) 19 (7.7) Cefoperazone-sulbactam 4 (1.2) 0 (0.0) 4 (1.6) Cefcapene 4 (1.2) 1 (1.3) 3 (1.2) Ceftazidime 3 (0.9) 2 (2.5) 1 (0.4) Cefditoren 3 (0.9) 1 (1.3) 2 (0.8) Penicillin combinations 43 (13.1) 16 (20.3) 27 (10.9) Piperacillin-tazobactam 22 (6.7) 3 (3.8) 19 (7.7) Ampicillin-sulbactam 19 (5.8) 12 (15.2) 7 (2.8) Amoxicillin-clavulanate 2 (0.6) 1 (1.3) 1 (0.4) Sulfonamide and trimethoprim combinations 27 (8.3) 4 (5.1) 23 (9.3) Trimethoprim-sulfamethoxazole 27 (8.3) 4 (5.1) 23 (9.3) Extended-spectrum penicillins 26 (8.0) 5 (6.3) 21 (8.5) Piperacillin 18 (5.5) 1 (1.3) 17 (6.9) Ampicillin 5 (1.5) 1 (1.3) 4 (1.6) Amoxicillin 3 (0.9) 3 (3.8) 0 (0.0) Second-generation cephalosporins 26 (8.0) 12 (15.2) 14 (5.6) Cefmetazole 21 (6.4) 9 (11.4) 12 (4.8) Cefotiam 4 (1.2) 3 (3.8) 1 (0.4) Cefaclor 1 (0.3) 0 (0.0) 1 (0.4) Fluoroquinolones 20 (6.1) 0 (0.0) 20 (8.1) Levofloxacin 18 (5.5) 0 (0.0) 18 (7.3) Ciprofloxacin 1 (0.3) 0 (0.0) 1 (0.4) Tosufloxacin 1 (0.3) 0 (0.0) 1 (0.4) Triazole antifungals 12 (3.7) 0 (0.0) 12 (4.8) Fluconazole 11 (3.4) 0 (0.0) 11 (4.4) Itraconazole 1 (0.3) 0 (0.0) 1 (0.4) Carbapenems 9 (2.8) 0 (0.0) 9 (3.6) Meropenem 9 (2.8) 0 (0.0) 9 (3.6) 7

Glycopeptide (parenteral) 8 (2.4) 1 (1.3) 7 (2.8) Vancomycin 8 (2.4) 1 (1.3) 7 (2.8) Macrolides 8 (2.4) 3 (3.8) 5 (2.0) Erythromycin 4 (1.2) 1 (1.3) 3 (1.2) Clarithromycin 3 (0.9) 1 (1.3) 2 (0.8) Azithromycin 1 (0.3) 1 (1.3) 0 (0.0) Fourth-generation cephalosporins 7 (2.1) 0 (0.0) 7 (2.8) Cefozopran 6 (1.8) 0 (0.0) 6 (2.4) Cefepime 1 (0.3) 0 (0.0) 1 (0.4) Nucleoside and nucleotide antivirals 4 (1.2) 0 (0.0) 4 (1.6) Valaciclovir 2 (0.6) 0 (0.0) 2 (0.8) Ganciclovir 1 (0.3) 0 (0.0) 1 (0.4) Famciclovir 1 (0.3) 0 (0.0) 1 (0.4) Tetracyclines 4 (1.2) 2 (2.5) 2 (0.8) Minocyclin 4 (1.2) 2 (2.5) 2 (0.8) aAntimicrobial drugs were classified and reported based on the World Health Organization Anatomical Therapeutic Chemical fifth-level classification. bValues are the number of antimicrobial drugs, with the percentage of the total number of antimicrobial drugs in parenthesis according to the site.

Table S5. Number and type of antimicrobial drugs given to treat infections according to the survey sitea. Type Total Site A Site B Total antimicrobial drugs 163 (100.0) 43 (100.0) 120 (100.0) Ceftriaxone 25 (15.3) 9 (20.9) 16 (13.3) Piperacillin-tazobactam 22 (13.5) 3 (7.0) 19 (15.8) Cefmetazole 13 (8.0) 7 (16.3) 6 (5.0) Cefazolin 12 (7.4) 6 (14.0) 6 (5.0) Ampicillin-sulbactam 12 (7.4) 5 (11.6) 7 (5.8) Meropenem 9 (5.5) 0 (0.0) 9 (7.5) Vancomycin (parenteral)b 8 (4.9) 1 (2.3) 7 (5.8) Levofloxacin 6 (3.7) 0 (0.0) 6 (5.0) Cefozopran 6 (3.7) 0 (0.0) 6 (5.0) Ampicillin 5 (3.1) 1 (2.3) 4 (3.3) Cefoperazone-sulbactam 4 (2.5) 0 (0.0) 4 (3.3) Ceftazidime 3 (1.8) 2 (4.7) 1 (0.8) Trimethoprim-sulfamethoxazole 3 (1.8) 1 (2.3) 2 (1.7) Amoxicillin 2 (1.2) 2 (4.7) 0 (0.0) Amoxicillin-clavulanate 2 (1.2) 1 (2.3) 1 (0.8) Piperacillin 2 (1.2) 1 (2.3) 1 (0.8) Cefcapene 2 (1.2) 0 (0.0) 2 (1.7) Minocycline 2 (1.2) 1 (2.3) 1 (0.8) Rifampicine 2 (1.2) 0 (0.0) 2 (1.7) Micafungin 2 (1.2) 0 (0.0) 2 (1.7) Cefalexin 1 (0.6) 1 (2.3) 0 (0.0) Cefaclor 1 (0.6) 0 (0.0) 1 (0.8) Cefotiam 1 (0.6) 0 (0.0) 1 (0.8) Cefditoren 1 (0.6) 1 (2.3) 0 (0.0) Cefepime 1 (0.6) 0 (0.0) 1 (0.8) Ciprofloxacin 1 (0.6) 0 (0.0) 1 (0.8) Tosufloxacin 1 (0.6) 0 (0.0) 1 (0.8) Clindamycin 1 (0.6) 0 (0.0) 1 (0.8) Clarithromycin 1 (0.6) 0 (0.0) 1 (0.8) Azithromycin 1 (0.6) 1 (2.3) 0 (0.0) Fosfomycin 1 (0.6) 0 (0.0) 1 (0.8) Vancomycin (enteral)c 1 (0.6) 0 (0.0) 1 (0.8) 9

Metronidazole (parenteral)b 1 (0.6) 0 (0.0) 1 (0.8) Metronidazole (enteral)c 1 (0.6) 0 (0.0) 1 (0.8) Daptomycin 1 (0.6) 0 (0.0) 1 (0.8) Linezolid 1 (0.6) 0 (0.0) 1 (0.8) Fluconazole 1 (0.6) 0 (0.0) 1 (0.8) Itraconazole 1 (0.6) 0 (0.0) 1 (0.8) Amphotericin B (parenteral)b 1 (0.6) 0 (0.0) 1 (0.8) Famciclovir 1 (0.6) 0 (0.0) 1 (0.8) Ganciclovir 1 (0.6) 0 (0.0) 1 (0.8) aValues are the number of antimicrobial drugs, with the percentage of the total number of antimicrobial drugs in parenthesis according to the site. bParenteral formulation of the drug. cEnteral formulation of the drug. 10

Table S6. Infection sites for which patients received antimicrobial therapy. Total Site A Site B Number of Number of Number of Number of Number of Number of Infection sitea drugsb, n (%) patientsc, n drugsb, n patientsc, n drugsb, n patientsc, n (n = 163) (%) (%) (%) (%) (%) (n = 140) (n = 43) (n = 40) (n = 120) (n = 100) Lower respiratory tract 44 (27.0) 34 (24.3) 4 (9.3) 3 (7.5) 40 (33.3) 31 (31.0) Bloodstream 32 (19.6) 28 (20.0) 9 (20.9) 9 (22.5) 23 (19.2) 19 (19.0) Urinary tract 25 (15.3) 21 (15.0) 8 (18.6) 7 (17.5) 17 (14.2) 14 (14.0) Hepatobiliary system 23 (14.1) 22 (15.7) 10 (23.3) 10 (25.0) 13 (10.8) 12 (12.0) Skin and soft tissue 14 (8.6) 12 (8.6) 7 (16.3) 6 (15.0) 7 (5.8) 6 (6.0) Intra-abdominal 12 (7.4) 9 (6.3) 3 (7.0) 3 (7.5) 9 (7.5) 6 (6.0) Empirical/undetermined 11 (6.7) 11 (7.9) 1 (2.3) 1 (2.5) 10 (8.3) 10 (10.0) Gastrointestinal tract 10 (6.1) 10 (7.1) 3 (7.0) 3 (7.5) 7 (5.8) 7 (7.0) Eye, ear, nose, throat, or 9 (5.5) 9 (6.3) 5 (11.6) 5 (12.5) 4 (3.3) 4 (4.0) mouth Central nervous system 3 (1.8) 3 (2.1) 2 (4.7) 2 (5.0) 1 (0.8) 1 (1.0) Bone and joint 3 (1.8) 3 (2.1) 2 (4.7) 2 (5.0) 1 (0.8) 1 (1.0) Cardiovascular system 3 (1.8) 2 (1.4) 0 (0.0) 0 (0.0) 3 (2.5) 2 (2.0) Reproductive tract 2 (1.2) 1 (0.7) 0 (0.0) 0 (0.0) 2 (1.7) 1 (1.0) Others 3 (1.8) 3 (2.1) 0 (0.0) 0 (0.0) 3 (2.5) 3 (3.0) aAntimicrobial drugs and patients could be given for more than one infection site. bValues are the number of antimicrobial drugs, with the percentage of the total number of antimicrobial drugs in parenthesis. cValues are the number of patients, with the percentage of the total number of patients receiving antimicrobial drugs in parenthesis.

Table S7. Appropriateness of the 163 antimicrobial drugs used for treatment according to the location in the hospital, specialty, type of antimicrobial drug, and type of infection. Number of Total number of uses inappropriate uses Location in hospital Ward 146 57 (39.0) Critical care unit 17 5 (29.4) Specialtya Internal medicine 73 21 (28.8) General surgery 33 16 (48.5) Paediatrics 10 4 (40.0) Urology 8 2 (25.0) Neurosurgery 7 4 (57.1) Cardiac surgery 7 2 (28.6) Orthopaedic surgery 6 4 (66.7) Haematology 6 4 (66.7) Type of antimicrobial druga Ceftriaxone 25 12 (48.0) Piperacillin-tazobactam 22 9 (40.9) Cefmetazole 13 4 (30.8) Cefazolin 12 1 (8.3) Ampicillin-sulbactam 12 6 (50.0) Vancomycin 9 2 (22.2) Meropenem 9 5 (55.6) Levofloxacin 6 3 (50.0) Cefozopran 6 5 (83.3) Ampicillin 5 2 (40.0) Site of infectiona Lower respiratory tract 44 13 (29.6) Bloodstream 32 7 (21.9) Urinary tract 25 11 (44.0) Hepatobiliary system 23 8 (34.8) Skin and soft tissue 14 5 (35.7) Intra-abdominal 12 8 (75.0) Empirical/undetermined 11 7 (63.6) 12

Gastrointestinal tract 10 4 (40.0) Eye, ear, nose, throat, or mouth 9 4 (44.4) aOnly those antimicrobial drugs representing more than three percent of the antimicrobial drugs given to treat infections are considered here. 13

Table S8. Type and duration of antimicrobial druga used for surgical prophylaxisb. Total Site A Site B N = 101 N = 28 N = 73 Duration Mean days (SD) 2.4 (2.0) 2.5 (1.3) 2.4 (2.3) Median days (IQR) 2 (1 – 3) 2 (2 – 3) 2 (1 – 3) One day 31 (30.7) 4 (14.3) 27 (37.0) Two days 30 (29.7) 11 (39.3) 19 (26.0) More than two days 40 (39.6) 13 (46.4) 27 (37.0) Type of antimicrobial drugs Cefazolin 56 (55.4) 13 (46.4) 43 (58.9) Piperacillin 16 (15.8) 0 (0.0) 16 (21.9) Ampicillin-sulbactam 7 (6.9) 7 (25.0) 0 (0.0) Cefmetazole 7 (6.9) 2 (7.1) 5 (6.8) Levofloxacin 3 (3.0) 0 (0.0) 3 (4.1) Cefotiam 3 (3.0) 3 (10.7) 0 (0.0) Ceftriaxone 2 (2.0) 1 (3.6) 1 (1.4) Others 7 (6.9) 2 (7.1) 5 (6.8) aA total of 101 antimicrobial drugs were given to 99 patients for surgical prophylaxis. bValues are the number of antimicrobial drugs, with the percentage of the total number of antimicrobial drugs in parenthesis unless stated otherwise. IQR, interquartile range; SD, standard deviation.

Table S9. All reported causative pathogensa among 63 health care-associated infections according to the survey siteb. Total Site A Site B Organisms N = 63 N = 13 N = 50 Klebsiella pneumoniae or Klebsiella oxytoca 7 (11.1) 1 (7.7) 6 (12.0) Cefazolin susceptiblec 6 (9.5) 1 (7.7) 5 (10.0) ESBL producingd 0 (0.0) 0 (0.0) 0 (0.0) Escherichia coli 6 (9.5) 1 (7.7) 5 (10.0) Ampicillin susceptiblec 3 (4.8) 0 (0.0) 3 (6.0) Cefazolin susceptiblec 5 (7.9) 0 (0.0) 5 (10.0) ESBL producingd 1 (1.6) 1 (7.7) 0 (0.0) Staphylococcus aureus 4 (6.3) 1 (7.7) 3 (6.0) MSSAc 3 (4.8) 0 (0.0) 3 (6.0) MRSAc 1 (1.6) 1 (7.7) 0 (0.0) Candida speciese 3 (4.8) 1 (7.7) 2 (4.0) Enterobacter cloacae 2 (3.2) 1 (7.7) 1 (2.0) Bacteroides speciesf 2 (3.2) 1 (7.7) 1 (2.0) Clostridioides (Clostridium) difficile 2 (3.2) 0 (0.0) 2 (4.0) Virusesg 2 (3.2) 0 (0.0) 2 (4.0) Burkholderia cepacia 1 (1.6) 0 (0.0) 1 (2.0) Pseudomonas aeruginosa 1 (1.6) 0 (0.0) 1 (2.0) Haemophilus influenzae 1 (1.6) 0 (0.0) 1 (2.0) Cryptococcus neoformans 1 (1.6) 0 (0.0) 1 (2.0) Enterococcus faecalis 1 (1.6) 0 (0.0) 1 (2.0) Citrobacter freundii 1 (1.6) 0 (0.0) 1 (2.0) Corynebacterium striatum 1 (1.6) 0 (0.0) 1 (2.0) Gemella morbillorum 1 (1.6) 0 (0.0) 1 (2.0) Streptococcus anginosus 1 (1.6) 1 (7.7) 0 (0.0) Stenotrophomonas maltophilia 1 (1.6) 0 (0.0) 1 (2.0) aNo microbial tests were performed in 7 (11.1%) of 63 health care-associated infections. Blood culture, sputum culture, and urine culture were performed in 44 (69.8%), 18 (28.6%), and 18 (28.6%) of all health care-associated infections, respectively. No significant organisms were reported in 26 of 56 health care-associated infections (46.4%) that were investigated by any microbial tests. One or more pathogens were reported for six infections. 15

bValues are the number of infections, with the percentage of the total number of healthcare-associated infections in parentheses according to the survey site. cSusceptibility was determined based on the Clinical and Laboratory Standard Institute breakpoint. dESBL production was confirmed by local laboratory methods of surveyed hospitals. eCandida species include Candida albicans (n = 2) and Candida parapsilosis (n = 1). fBacteroides species include Bacteroides fragilis (n =1) and Bacteroides thetaiomicron (n = 1). gViruses include cytomegalovirus (n = 1) and hepatitis B virus (n = 1). ESBL, extended-spectrum β-lactamase; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus.

Table S10. Number and type of antimicrobial drugs given to treat healthcare-associated infections according to the survey sitea. Type Total Site A Site B Total antimicrobial drugs 70 (100.0) 12 (100.0) 58 (100.0) Piperacillin-tazobactam 12 (17.1) 1 (8.3) 11 (19.0) Cefazolin 8 (11.4) 3 (25.0) 5 (8.6) Vancomycin (parenteral)b 8 (11.4) 1 (8.3) 7 (12.1) Ceftriaxone 6 (8.6) 1 (8.3) 5 (8.6) Meropenem 6 (8.6) 0 (0.0) 6 (10.3) Ampicillin-sulbactam 5 (7.1) 1 (8.3) 4 (6.9) Cefozopran 4 (5.7) 0 (0.0) 4 (6.9) Cefmetazole 2 (2.9) 2 (16.7) 0 (0.0) Ceftazidime 2 (2.9) 1 (8.3) 1 (1.7) Levofloxacin 2 (2.9) 0 (0.0) 2 (3.4) Minocycline 2 (2.9) 1 (8.3) 1 (1.7) Micafungin 2 (2.9) 0 (0.0) 2 (3.4) Amoxicillin-clavulanate 1 (1.4) 1 (8.3) 0 (0.0) Cefepime 1 (1.4) 0 (0.0) 1 (1.7) Metronidazole (enteral)c 1 (1.4) 0 (0.0) 1 (1.7) Trimethoprim-sulfamethoxazole 1 (1.4) 0 (0.0) 1 (1.7) Fosfomycin 1 (1.4) 0 (0.0) 1 (1.7) Vancomycin (enteral)c 1 (1.4) 0 (0.0) 1 (1.7) Linezolid 1 (1.4) 0 (0.0) 1 (1.7) Amphotericin B (parenteral)b 1 (1.4) 0 (0.0) 1 (1.7) Fluconazole 1 (1.4) 0 (0.0) 1 (1.7) Famciclovir 1 (1.4) 0 (0.0) 1 (1.7) Ganciclovir 1 (1.4) 0 (0.0) 1 (1.7) aValues are the number of antimicrobial drugs, with the percentage of the total number of antimicrobial drugs in parenthesis according to the site. bParenteral formulation of the drug. cEnteral formulation of the drug. 17

Table S11. Causative pathogensa reported in two or more patients and their infection sites among 140 patients receiving antimicrobial therapyb. Eye, ear, Lower Gastroint Hepato Intra- Intra- Total Urinary nose, Organisms Blood respiratory estinal biliary abdomin thoracic Device N = 140 tract throat, or tract tract system al space space mouth

Escherichia coli 17 8 0 9 1 5 0 0 0 0 Ampicillin susceptiblec 11 4 0 6 1 4 0 0 0 0 Cefazolin susceptiblec 15 6 0 8 0 5 0 0 0 0 ESBL producingd 2 1 0 1 0 0 0 0 0 0

Klebsiella speciese 13 3 0 2 1 4 1 0 0 1 Cefazolin susceptiblec 10 3 0 1 1 5 1 0 0 0 ESBL producingd 0 0 0 0 0 0 0 0 0 0 Streptococcus speciesf 7 5 1 0 0 0 0 1 0 1 Staphylococcus aureus 7 5 1 0 0 0 1 0 0 0 MRSAc 1 0 1 0 0 0 0 0 0 0 MSSAc 6 6 0 0 0 0 1 0 1 0 Enterobacter speciesg 4 3 0 1 0 0 0 0 0 0 Enterococcus speciesh 4 0 0 2 0 1 1 0 0 0 Pseudomonas aeruginosa 3 2 1 0 0 0 0 0 0 0

Candida speciesi 2 1 0 0 0 0 1 0 0 0 Bacteroides speciesj 2 1 0 0 1 0 0 0 0 0 Clostridioides difficile 2 0 0 0 2 0 0 0 0 0 Virusesk 2 0 0 0 0 0 0 0 0 2 Haemophilus influenza 2 1 1 0 0 0 0 0 0 0 Ampicillin susceptiblec 1 0 1 0 0 0 0 0 0 0 Fusobacterium nucleatum 2 0 0 0 0 0 1 1 0 0 aNo microbial tests were performed in 21 (15.0%) of 140 patients who received antimicrobial therapy. Blood culture, sputum culture, and urine culture were performed in 99 (70.7%), 36 (25.7%), and 45 (32.1%) of all patients receiving antimicrobial drugs, respectively. Organisms were cultured by local laboratory methods of surveyed hospitals. No significant organisms were reported in 50 of 119 patients (42.0%) who were evaluated by any microbial tests. bValues are the number of patients. Organisms could be given for more than one infection site. 18

cSusceptibility was determined based on the Clinical and Laboratory Standard Institute breakpoint. dESBL production was confirmed by local laboratory methods of surveyed hospitals. eKlebsiella species include Klebsiella pneumoniae (n = 9) and Klebsiella oxytoca (n = 4). fStreptococcus species include Group A Streptococci (n = 2), Streptococcus anginosus (n = 1), Streptococcus constellatus (n = 1), Streptococcus oralis (n = 1), Streptococcus dysgalactiae (n=1), and Streptococcus pneumoniae (n = 1). gEnterobacter species include Enterobacter cloacae (n = 3) and Enterobacter aerogenes (n = 1). hEnterococcus species include Enterococcus faecalis (n = 2), Enterococcus casseliflavus (n = 1), and Enterococcus gallinarum (n = 1). iCandida species include Candida albicans (n = 1) and Candida parapsilosis (n = 1). jBacteroides species include Bacteroides fragilis (n =1) and Bacteroides thetaiomicron (n = 1). kViruses include cytomegalovirus (n = 1) and respiratory syncytial virus (n = 1). ESBL, extended-spectrum β-lactamase; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus.