Microbiological Evaluation of Surgical Site Infections in the Clinic of Oral and Maxillofacial Surgery of the Sf.Spiridon Clinical Hospital in Iasi, Romania

MAGDA CALINA BARLEAN1, CARINA BALCOS2*, LIVIA IONELA BOBU3*, COSMIN IONUT CRETU4, ALEXANDRA LORINA PLATON5, ANCA STUPU6, OVIDIU NICOLAICIUC7, GABI TOPOR9, ADRIAN BEZNEA9, EUGENIA POPESCU8 1Grigore T.Popa University of Medicine and Pharmacy Iasi, Romania, Faculty of Dental Medicine, 16 Universitatii Str. 700115 9 Dunarea de Jos University of Galati, Faculty of Medicine and Pharmacy, 47 Domneasca Str., 800008, Galati, Romania

Healthcare associated infections (HAI) are infections occurring during health care and they are a major problem in healthcare systems worldwide [1]. The term of healthcare associated infection initially referred to those hospital-related infections (previously called nosocomial infections), includes today the infections developed in various locations where patients receive healthcare (hospitals, ambulatory medical institutions, long-term health care institutions, family medicine clinics, home care) [2].
HAI affect a large number of patients worldwide, significantly increasing the mortality rate and the financial losses associated with medical care.In Europe The Centre for Disease Control and Prevention (ECDC) appreciates that of the 100 hospitalized patients, 7 patients in advanced countries and 10 in developing country acquire an HAI. Following the conclusions of extended reviews in the literature a report drawn up in 2016 by the World Health Organization pointed outthat the prevalence of HAI varies according to the socio-economic status with estimated values between 3.5% and 12% in the countries with high socio-economic status, compared to 5.7% -19.1% (average prevalence 10.1%) in the middle and low income countries [3,4].
The most common locations of HAI are the surgical site, the urinary tract and lungs, but theycan affect the digestive system or can cause serious systemic infections. [5,6]The CDC in partnership with the World Health Organization and other organizations and agencies around the world are making sustained efforts that are reflected in the adopted specific strategies involving actions at institutional, national and international level. In Romania, these regulations at national level are included in Order no. 1101/2016 on the approval of the Norms for the surveillance, prevention and limitation of healthcare associated infections in medical establishments [7].
Surgical site infections (SSI) are the most common type of HAImainly in low and middle income countries with an incidence between 1.2 and 23.6 per 100 surgical * email: carinutza 2005@yahoo.com; livia12mi@yahoo.com procedures and an average of 11.8 % compared to the incidence reported in developed countries ranging between 1.2% and 5.2% [8]. SSI are defined as infections occurring up to 30 days after surgery and affecting the incision or tissues at the site of the surgical intervention. Despite advances in prevention, SSI remains a major clinical problem because they are associated with significant mortality and morbidity and require considerable medical resource demand.
Thesurgery interventions for head and neck cancerare frequently associated with SSI which are reported to be the most common and significant complications despite antibiotic prophylaxis [9,10].These infections can causeserious complications, asimportant deterioration of the operative wound, mucocutaneous fistula, sepsis and death [11,12].
Microbiological evaluations highlighted that the first identified pathogens involved in HAI were the Grampositive species, particularly Streptococci and Staphylococcus aureus, which caused major nosocomial infections culminating with the 1940-1950's pandemic. At the end of the 20th century Gram-positive bacteria (Staphylococcus aureus, Coagulase-negative Staphylococci and Enterococci) and Gram-negative bacteria (Escherichia coli, P. aeruginosa, Enterobacter spp. and Klebsiella pneumoniae)accounted for 34% and respectively 32% of pathogens associated with HAI [13].
Acquired antimicrobial resistance is the main problem in hospital units involving major Gram-positive and Gramnegative pathogens [14,15]. In 2013, CDC published a report on the main 18 antibiotic-resistant pathogens frequently associated with the aetiology of HAI, classified by risk. At present, the pathogens under surveillance for antibiotic resistance are Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter spp. [16,17].
The World Health Organization classifies pathogens according to the evolution of their antibiotic resistance in three priority levels: Critical,High and Average highlighting the need for vigorous measures to control this phenomenon [18]. In the critical category are included Acinetobacter baumanniicarbapenem -resistant Pseudomonas aeruginosa 3 rd generation cephalosporin-resistant Pseudomonas aeruginosa, 3 rd generation cephalosporinresistant . Surprisingly, Clostridium difficile is not included in the WHO list, although the incidence and severity of infections caused by this pathogen have increased dramatically since the beginning of the 2000s across Europe [19]. Statistical analysis of the data was performed using theSPSS 20 system (SPSS Inc., Chicago, IL, USA). Chisquare and Fisher tests were used to compare the variables. The statistical significance was set at p <0.05.

Results and discussions
A total number of 231 healthcare associated infections (HAI) were reported in Oral and Maxillofacial Surgery Clinic at the Sf.Spiridon Clinical Hospital in Iasi between 2011-2018, involving 154 patients.Thisinvestigation results are consistent with those reported by the World Health Organization on the prevalence of HAI as being between 5.7% and 19.1% (mean value 10.1%) for middle and low income countries [3]. They show to be higher than the average of 6% patients with at least one HAI reported by the European Centre for Disease Control and Prevention (ECDC) for 231,459 patients in 947 hospitals in 30 European countries. [20]HAI are caused by antibioticenhanced pathogens, hospitalized patients undergoing surgery frequently experiencing comorbidities associated with compromised immune systems that do not provide the necessary level of protection. In some cases, patients develop HAI infections due to non-compliance with hygiene conditions and infection prevention protocols in healthcare facilities due to under-funding or lack of knowledge and responsibility of healthcare professionals [21]. 125 surgical site infections (SSI) have been reported accounting for 54.1% of the total HAI diagnosed in 106 patients, representing 66,6% of all patients with HAI. Those results are well above the value of 33% reported at the European level [20] and by other authors: 10.0% -Ogihara [22], 28.3% -Yang [23]. The SSI incidence in the literature is appreciated to be up to 20%, depending on the surgical procedure, the used surveillance criteria, and the quality of the data collection [6]. SSI have important consequences on the progression and prognosis of the patient's initial hospitalization disease, but also on the financial burden in relation with the increased number of hospitalization days and the required specific treatment [24].
29 SSI (23.2%) were diagnosed in female patients and 96 (76.8%) in male patients. The patients 'gender was a significant risk factor for SSI in the current study, 76.9% of the patients with reported SSI being men. This finding is consistent with the studies of Park in 2016 [5], Belusic-Gobic et al. in 2007 [26] and Lee et al. in 2011 [9], while other studies have reported significant association between those infections and other factors as basic systemic diseases (Schwartz et al., 2004) [27].
Depending on the location SSI are classified as superficial involving only cutaneous and subcutaneous tissues and deep affecting the deep soft tissue of the incision. They imply signs as purulent drainageor a nonhistological abscess, spontaneous dehiscence of the wound with symptoms of infection (swelling, erythema, warmth and tenderness) and isolation of a pathogen in the purulent discharge [28,29]. In our study 57 SSI, representing 46,6% of total number of SSI and 24.6% of the total HAI, were superficial and 68 (54.4% of the SSI and 29.4% of HAI were deep . The distribution of SSI cases per year between 2011 and 2018 is shown in Table 1. Most SSI (80%) were associated with surgical procedures in patients diagnosed with head and neck cancer who required interventions on wide and deep tissue and / or flap reconstruction approaches.. In its study on SSI in 697 patients with major head and neck cancer surgery, Lee et al., 2011 [9] mentions the associated radiotherapy, the tracheotomy and the exposure to contamination as risk factors for those infectious complications. The occurrence of postoperative complications was also associated with disease severity, type of surgery and type of reconstruction [30]. Complications following major surgery for oral cancer patients increase the cost of treatment, delay adjuvant therapies, increase the risk of sequelae, affect the patient quality of life, and also may cause the death of a patient if they are not properly diagnosed and treated [22,31].
The average period of hospitalization for the patients diagnosed with SSI was 30 days, much higher than the average of 5-7 days (between 2.5 and 7.8 days) reported in Europe [15]. The emergence of an SSI may lead to a prolongation of hospitalization period , increased health care costs and delayed access to postoperative therapy [33].
Microbiological data (pathogens identification and their susceptibility to antibiotics) was obtained in all 106 patients with SSI. For 82 of them (65.6% of SSI), one pathogen agent was identified while 43 (34.4%) were associated with two or more pathogens. The assessment of the main determinants of HAI is an essential step in identifying the strategies and efficient measures for their control [32]. In hospital units the sources of infection are represented by patients, healthcare professionals and environment, but there are situations in which they remain unidentified. The oral cavity is a natural habitat for over 500 opportunistic and pathogenic microbial species, an ecological niche that increases the risk of infection transmission locally, regionally and systemically by exposure to microorganisms during invasive procedures of oral surgery.
The most commonly identified pathogens from the 174 isolates for SSI were Klebsiella Pneumoniae -18.4%, Staphylococcus aureus18.4%, Acinetobacter baumanii -17.2% and Pseudomonas aeruginosa -14.4%, followed by Escherichia coli -5.7%, Enterococcus faecalis -5.2%, Enterobacter spp. 4% and Staphylococcus epidermidis -2.9%. (fig.1) An impressive number of studies in the literature aim to identify the most involved in SSI pathogens.Our study data are comparable with the results of extensive studies conducted in France, Germany and Italy, including 13 954 isolates in which the most common reported pathogens were Staphylococcus aureus (21.8%), Enterobacteriaceae (20.2%), Pseudomonas spp. (17.2%), Enterococci (10.0%), Escherichia coli (9.1%), Candida spp (8.8%), Coagulasenegative staphylococci (7.0%)and Acinetobacter spp (5.1%). [3] An increased frequency of Klebsiella pneumoniae isolations must be mentioned as a result of the present investigation. Of the total of 167 strains of isolated bacteria involved in the aetiology of SSI , 113 (67.7%) were Gram-negative bacteria and 54 (32.3%) Gram-positive bacteria, results comparable with those highlighted by a recently published synthesis study based on 28 studies in developing countries which reported that Gram-negative bacteria are the pathogens most commonly associated with HAI in all patients as well as in patients at high risk. (fig.2) [9]. For emerging countries, a growing proportion of nosocomial infections attributed to Gramnegative bacteria and to methicillin-resistant Staphylococcus aureus (MRSA) have been reported by Fehr et al. 2006 [34], Rosenthal et al. 2006 [35] and Kadkhodaei, 2018 [36].
The results of our study reveal a high level of resistance to antibiotics of the pathogens associated with SSI confirming the literature findingswhich demonstrates that up to 60% of microorganisms isolated from infected surgical wounds are resistant to antibiotic treatment [3].Resistance to antibiotics is a major problem in the hospital environment, with a gradual but marked change in bacterial epidemiology with significant implications for the prevention and cure of infections. In Europe it is demonstrated that 75% of the burden of bacteria resistant to antibiotics is due to healthcare-associated infections. The impact of antimicrobial resistance extends beyond the increased health risks and has many consequences and major implications for public health systems being associated with financial losses in the global economy due to reduced productivity and higher treatment costs. In order to limit them, there is a need for long-term financial investment and technical support, especially in developing countries,cautious use of antibiotics, the emergence of new antimicrobial drugs, new diagnostic techniques, vaccines and other interventions to ensure adequate the use and access to efficient antimicrobial agents [40].

Conclusions
The incidence of healthcare-associated infections is increasing as a major problem for healthcare systems around the world with medical, financial, social, and ethical implications. Surgical site infections occur with an increased frequency associated primarily with tumour pathology surgery.Most pathogens involved in the aetiology of SSI are resistant to antibiotics, a phenomenon that characterizes the evolution of bacterial epidemiology in the medical units.In order to prevent and control the SSI standardized strategies are recommended with proven effectiveness in a global , multidisciplinary and innovative approach.