A. faecalis infection cases (Table 5)
Table 5
Alcaligenes faecalis infection cases
Year/diagnosis
|
Before 1997
|
1997 to 2019
|
Our cases
|
UTI
SSTI
Pneumonia
APN
Bacteremia
Empyema
Otitis medium
Meningitis
Endocarditis
Ocular infection
Peritonitis
Infectious diarrhea
Miscellaneous
Total
|
0
0
0
0
39
0
0
15
2
2
0
3
1
62
|
10
12
6
0
3
0
21
1
1
8
2
0
2
66
|
25
11*
8
7
3
2
2
0
0
0
1
0
2
61
|
*: including 9 cases of diabetic foot infection, 1 case of surgical wound infection and 1 case of burn wound infection. |
To our knowledge, sixty-two A. faecalis infection cases were sporadically reported in the medical literature before 1997 [27–42]. The most commonly reported cases involved bacteremia and meningitis, and most cases occurred in newborns and infants. No adequate information was mentioned in the literature during this period. Most cases were treated with sulfonamide. Inappropriate and inadequate infection control strategies may be the cause of A. faecalis meningitis and A. faecalis bacteremia in high-risk newborns and infants. In 1960, Doxiadis reported 33 cases of bacteremia in newborns, which was the largest cases series before 1997 [36]. A. faecalis was resistant to sulfonamides, and there were 20 deaths due to A. faecalis bacteremia.
To our knowledge, there were 66 sporadically reported cases of A. faecalis infection in the literature after 1997 [5–26]. Fillipe reported 20 cases of chronic otitis media in Angola [19]. The use of bird feces by residents as a traditional remedy to prevent ear discharge was related to these A. faecalis chronic otitis media cases. The other infections from A. faecalis, in order of occurrence, were skin and soft tissue infection (SSTI), UTI, endophthalmitis, and pneumonia. In our series, the most frequent cases were, in order, UTI, SSTI, and pneumonia. We did not find any cases of endophthalmitis. The cases reported in the literature after 1997 (excluding the 20 cases of chronic otitis media in Angola) and our cases indicate that the most frequent A. faecalis infection sites, in order, were the urinary tract, skin and soft tissue (diabetic foot ulcer accounts for 56.5% of skin and soft tissue infection), and lung.
The trend of antibiotic sensitive rate of A. faecalis
In 1997, Bizet reported that A. faecalis strains were resistant to amoxicillin, ticarcillin, and gentamicin [5]. Amoxicillin-clavulanic acid and cefotaxime provided a successful treatment outcome for patients with A. faecalis infection. This means that A. faecalis with β-lactamase emerged in 1997. In 2000, Pereira reported that a strain of A. faecalis resistant to expanded-spectrum cephalosporins was isolated from the urine of an inpatient [6]. Clavulanic acid restored the activity of expanded-spectrum cephalosporins, suggesting the production of an extended-spectrum β-lactamase (ESBL). In 2005, Dubois described the isolation of A. faecalis with ESBL in a patient with a concurrent urinary tract infection [11]. In 2017 and 2018, 2 cases of XDR A. faecalis pneumonia were reported by Agarwal and Junejo [22, 23]. In 2019, Hasan reported a 60-year-old female with pandrug-resistant A. faecalis bacteremia who was treated with double-dose tigecycline, and had a successful treatment outcome [26]. It was terrible that a pandrug-resistant A. faecalis pathogen had been found.
In our hospital, the strain of A. faecalis was sensitive to all commonly used antibiotics before April 2014. The strain of A. faecalis resistant to ciprofloxacin was first seen in a case of APN in April 2014. The strain of A. faecalis was resistant to cefepime in a case of UTI in August 2014. In March 2015, the strain A. faecalis showed sensitivity only to imipenem and meropenem in a pneumonia patient. In May 2018, a strain of XDR A. faecalis susceptible only to tigecycline was isolated from a pneumonia patient. In only 4 years, the A. faecalis strain changed into XDR A. faecalis, which was remarkably faster than in other literature reports. There were 4 cases with XDR A. faecalis infection in our series, including 2 cases of pneumonia and 2 cases of diabetic foot infection. All patients had a history of receiving intravenous many antibiotics within the past 90 days, which may be a risk factor for XDR A. faecalis infection.
In view of individual antibiotics, a very low sensitivity rate to ciprofloxacin was noted from 2014 to 2019. Piperacillin/tazobactam was significant in decreasing the sensitivity rate in 2016–2017. Amikacin significantly decreased the sensitivity rate in 2018–2019. Imipenem and meropenem were emerging resistant strains in 2018–2019.
With commonly used antibiotics, A. faecalis showed a markedly deceasing sensitivity rate very year. A high resistance rate of many antibiotics, such as anti-pseudomonas penicillin, cephalosporins, carbapenems, aminoglycosides, and quinolones, was found in 2018–2019. No antibiotic sensitivity rate to A. faecalis was greater than 90%. The best sensitivity rate to A. faecalis was 75% for three antibiotics (imipenem, meropenem, and ceftazidime). Two antibiotics (ciprofloxacin and piperacillin/tazobactam’s) sensitivity rates to A. faecalis were less than 50%. Optimal antibiotic therapy for A. faecalis was not well established in the literature. From our experience, we can suggest that ciprofloxacin, piperacillin/tazobactam, amikacin, and cefepime are not good choices for empiric therapy of A. faecalis infection. Instead, we choose an appropriate antibiotic for a susceptible A. faecalis infection patient according to the results of his or her antibiotics sensitivity test. If the A. faecalis organism is an ESBL strain, a carbapenem is an appropriate antibiotic. If the A. faecalis is an XDR strain, only polymyxin B or tigecycline is effective.
Treatment failure of A. faecalis infection cases
Among our reported cases of A. faecalis infection, one patient with stage IV adenocarcinoma of the lung (undergoing tyrosine kinase inhibitor therapy) did not receive adequate intravenous antibiotic therapy, and subsequently died due to A. faecalis pneumonia. Another patient with stage IV squamous cell carcinoma of the lung (undergoing chemotherapy) received adequate intravenous antibiotic therapy, but died due to A. faecalis pneumonia. Two patients died from urosepsis. One was a 98-year-old female, with hypertension and chronic kidney disease comorbidities. She did not receive adequate IV antibiotic therapy (cefoxitin) to treat A. faecalis infection. Another case involved a 75-year-old female with hypertension, diabetes mellitus and dementia. While she initially received adequate IV antibiotic (cefepime) therapy, nonetheless she died in the emergency room due to profound septic shock. In three cases, diabetic foot ulcers did not heal. One patient had wound infection complicated by septic shock. This patient underwent amputation of her right leg below the knee to save her life. One patient had comorbidities of peripheral artery disease and chronic kidney disease. The duration of his diabetic foot ulcer was 12 months. He received intravenous antibiotics with ceftazidime and teicoplanin therapy, as well as debridement, but the foot ulcer still failed to heal. One patient had comorbidities of peripheral artery disease, chronic kidney disease, hypoxic encephalopathy, and required prolonged mechanical ventilation. The duration of his diabetic foot ulcer was 18 months, and tests showed infection with XDR A. faecalis. Although the patient was treated with intravenous colistin and wound debridement, his diabetic foot ulcer failed to heal. The overall treatment failure rate was 11.5%. We studied twenty-four A. faecalis cases with reported treatment outcome in the literature after 1997. Among them, there were three treatment failure cases, including one peritonitis case, one pneumonia case and one diabetic foot ulcer case. The overall treatment failure rate was 12.5% [14, 17, 22]. The overall treatment failure rate was 12.5%. A. faecalis is a low virulence bacterium. With adequate intravenous antibiotic therapy, patients with A. faecalis infection will usually have a good treatment outcome.
Limitations
Our clinical study of A. faecalis infection was a small cases series and therefore can provide only minimal clinical experience. Additional case series reports of A. faecalis infection will add to the knowledge of how to treat this multi-resistant infection.