Antibiotic Resistance Pattern of Bacteria Causing Hospital Acquired Infections in the New Mansoura General Hospital, Egypt

Background: This study aims to describe the antibiotic resistance pattern among patients with hospital acquired infections in Mansoura New General Hospital (MNGH), Egypt and to identify the multidrug resistant organisms. Methods: A descriptive study was carried out in different departments of MNGH. All the 272 microbiological samples (blood, urine, swabs and others) from 259 patients with hospital acquired infections during the study period were processed in the bacteriology laboratory on different culture media. Bacterial isolates were identified by Gram-stain, cultures on routine media (e.g Blood agar, MacConkey agar) and specific biochemical tests following standard procedures. Antibiotic susceptibility testing was performed using disk diffusion methods. Multidrug-resistant (MDR) was defined as isolate non-susceptible to at least one agent in more than three antimicrobial categories. Results: The prevalence of methicillin-resistant Staphylocoocus aureus spp. ( S. aureus ) ( MRSA ) was 55.8%, methicillin-resistant Coagulase-negative (CoNS) was 100%, and vancomycin-resistant Enterococcus spp. (VRE) was 20%. Carbapenem resistant E. coli was 8.2%. Cephalosporin resistant (CephRy- Klebsiella spp.) was 85%, and carbapenem resistant K. pneumoniae spp. was 21.6. MDR-P. aeruginosa was 43.6% and MDR A. baumannii spp. was 100%. Conclusion: There is a need to integrate testing bacteria for antibiotics sensitivity in all nosocomial infections surveillance system. Policies on the control of antibiotic usage have to be implemented to avoid the emergence of newer generations of resistant pathogens.


Introduction
The emergence of antimicrobial resistance (AMR) is a global public health problem, particularly for pathogens causing nosocomial infections. Rates of AMR are increasing rapidly and resistance patterns show large variations between countries [1]. Infections caused by resistant pathogens result in significant morbidity and mortality, and contribute to increase healthcare costs worldwide. Despite the availability of newer antibiotics, emerging antimicrobial resistance has become an increasing problem in many pathogens throughout the world [2]. er patients, the environment, shared equipment, or hospital personnel [3].
Despite the presence of few studies in Egypt on antibiotic resistance none was done in Mansoura New General Hospital (MNGH). The objectives of this study are to describe the antibiotic resistance pattern among patients with nosocomial infections in MNGH. Egypt and to identify multidrug resistant organisms.

Materials and Methods
This descriptive study was done in MNGH, Egypt from 1/1/2017 to 31/12/2017. MNGH is a tertiary care hospital with 400 beds; it serves the Delta region of Egypt. It has 5 intensive care units (ICU) with 57 beds [general ICU (16 beds Every patient admitted to the hospital during the study period was monitored daily for developing nosocomial infections using standard definitions described by CDC [4]. A total of 272 microbiological specimens (87 blood, 83 urine, 61 surgical site swabs, 30 bronchial lavage/aspirate and 11 others) from 259 patients were processed in the bacteriology laboratory where they were isolated on different cultures. Bacterial isolates were identified by Gram-stain, cultures on routine media (e.g Blood agar, MacConkey agar) and specific biochemical tests following standard procedures. Antibiotic susceptibility testing was performed using disk diffusion methods and the result was interpreted according to the Clinical and Laboratory Standards Institute (CLSI) [5].
Multidrug-resistance (MDR) was defined according to CDC [6] as isolates which are non-susceptible to at least one agent in more than three antimicrobial categories. Specifically, an isolate of A. baymannii spp. was defined as having multidrug resistance (MDR) if it tested non-susceptible (i.e., resistant or intermediate) to at least one drug in three of the following six antimicrobial agents/groups: piperacillin or piperacillin/ tazobactam, extended-spectrum cephalosporins (cefepime or ceftazidime), aminoglycosides, ampicillin/sulbactam, carbapenems, and fluoroquinolones. For Pseudomonas aeruginosa spp. (P. aeruginosa) isolates, MDR was defined as testing non-susceptible (i.e., either resistant or intermediate) to at least one drug in three of the five following antimicrobial groups: piperacillin or piperacillin/tazobactam, extended-spectrum cephalosporins (cefepime or ceftazidime), fluoroquinolones, aminoglycosides, and carbapenems.
Data was analyzed using SPSS program version 16. Variables were presented as number and percent.

Results
The total number of isolated bacteria was 272 with 29.4% Gram positive bacteria (GPB) and 70.6% Gram negative bacteria (GNB). The most frequent GPB were S. aureus and Enterococcus spp. while the most frequent GNB were Klebsiella pneumoniae spp. (K. pneumoniae), E. coli spp. and P. aeruginosa spp. (Table 1).
Carbapenems (imipenem) resistance was observed in 71.4% of A. baumannii spp., 25.6%, 21.7% of P. aeruginosa spp. and 21.6% of Proteus spp., Resistance to Ciprofloxacin of Acinetobacter spp., P. aeruginosa spp., Proteus spp., K. pneumoniae spp.; respectively were resistant to imipenem. A previous Egyptian study reported that resistance to imipenem was totally absent or very low [13]. Another study in three large tertiary care university hospitals in Egypt, Imipenem resistance was detected in 23.5% of P. aeruginosa spp. isolates and in 27.6% of A. baumannii spp. isolates [1]. Studies in Turkey, Italy, and France reported the presence of low levels of resistance to imipenem [14].
There has been a dramatic increase in nosocomial infections due to antibiotic resistance and MDR pathogens throughout the world. MDR bacteria of concern include MRSA, VRE, MDR P. aeruginosa spp., and MDR A. baumannii spp. Most of the highprofile nosocomial organisms are MDR e.g. methicillin-resistant S. aureus spp. (MRSA). Multidrug-resistant-gram negative organisms (MDR-GNRs) have become increasingly prevalent in many hospitals [17]. In this study MRSA was 55.8%, Methicillin resistant CoNS was 100%. In a study at Assiut University Hospitals, Egypt stated that MRSA was 18.9% and CoNS methicillin resistance was 16% [18]. Worldwide, MRSA rates vary widely, from 1% in Denmark, Sweden, and The Netherlands to 40% in the United Kingdom, Greece, and Italy [19]. The US rate of r43 was 52.9%, and CoNS methicillin resistance was 76.6% [20]. VRE in this study was 20%. This is similar to a study in Korea [21]. However much higher rate was reported in Iran (42.9%) [8].
The high rate of GNP isolated from patients with nosocomial infections has a two clinical significance: A high prev-E. coli spp. resistance to carbapenem was 8.2%. Ceph R-Klebsiella spp. was 85%, and Carbapenem resistant K. pneumoniae spp. was 21.6%. MDR-Pseudomonas spp. was 43.6% and MDR Acinetobacter spp. was 100% (Table 4).

Discussion
In this study 74.4% S. aureus spp. isolates was resistant to penicillin. CoNS exhibit 100% and 75% resistant to cefoxitin and penicillin; respectively. Enterococci spp. isolates were mostly resistant to ampicillin (88%) and penicillin (80%). A study in three teaching hospitals in North of Iran, reported that 100% S. aureus spp. was resistant to penicillin, cefoxitin and quinolones. CoNS were resistant to penicillin, cefoxitin and quinolones (100%, 66% and 100%; respectively) [7]. In another study in Iranian hospital found that resistance to cefoxitin was 39.1%, quinolones resistant S. aureus spp. was 39.1%, and CoNS resistant to quinolones was 100%. Enterococci spp. resistance to ampicillin was 57.1% and vancomycin resistance was 42.9% [8].
Although linezolid antibiotic considered from second line treatment, it exhibits resistance by 23% 12.5% and 16% of S. aureus spp., CoNS by 12.5%, and Enterococci spp.; respectively. These results agreed with study in tertiary care University Hospital in India which revealed 77.5 % of organisms are resistant to linezolid [9]. Although in another study in China, revealed no resistant to linezolid [10]. Linezolid should be used if there is resistant to vancomycin and not prescribed routinely, however some clinicians use it as first line of treatment without indication this could explain the arising resistance for it.
In this study there is increase in resistant of GNB to both third (ceftazidime, cefotaxime, and cefoperazone), and fourth generation cephalosporin (cefepime). The rate of resistance to these generations of cephalosporins varies worldwide. An Iranian study found that 39% of P. aeruginosa spp. were resistant to cefepime, and 68% are resistant to ceftazidime [11]. A study in Morocco, showed that P. aeruginosa spp. resistance to ceftazidime was 35.6%, K. pneumoniae spp. resistance to ceftriaxone was 75.0% and to ceftazidime was 69.5%, and E. Coli spp. resistance to ceftriaxone was 31.9% and to ceftazidime was 21.7% [12].

Study Limitations
This is a single hospital study during a single year. Its results cannot be generalized to other hospital or during different periods. There is no breakdown of the resistance patterns by specific ward or department. Information from the specific departments may show specific strains dominating in those areas.

Conclusions
These results underline the need to integrate bacteria antibiotics sensitivity in all nosocomial infections surveillance system. Policies on the control of antibiotic usage have to be enforced and implemented to avoid the evolution of newer generations of pathogens with higher resistance, not only to the older generation drugs, but also to the relatively new ones. A nation-wide study is warranted to give the full picture of antibiotic resistance. Ongoing surveillance and test for antibiotic resistance will show the changing trends over time. These will help policy makers to develop a policy for antibiotic use in health care facilities.

Funding
None.

Conflict of Interest
None.

Ethical considerations
The study protocol was approved by IRB, Faculty of Medicine, Mansoura University as well as the Director of MNGH.