The excessive use of antibiotics has led to a vast widespread prevalence of antimicrobial resistance. As time passes, bacterial pathogens will defy every antibacterial option, thus, becoming extremely hard to control. Hence, the WHO identified it as an international health prime concern [12, 13].
To control this mounting predicament, comprehensive antibiotic stewardship in poor countries is fundamental. However, enough data regarding antimicrobial resistance are unavailable to precisely measure the extent of the problem. The few available studies concerning ICUs suggest that they are hotbeds of emerging high-level resistance. Hence, additional studies in other countries and healthcare settings are encouraged [14].
In this study, gram-negative isolates (57.5%, n = 736) were more prevalent compared to gram-positive ones (31.1%, n = 399). Comparable results were found by Halim et al. [15] where gram-negative bacteria took the upper hand among all nosocomial pathogens (53%) while gram-positive organisms represented 37.9%. Similarly, gram-negative organisms constituted 65.7% of cases in a study conducted by Sawhney and colleagues [16].
Most of the isolates were recovered from blood cultures (44.84%) followed by urine (41.41%), unlike the results of Shebl and Mosaad who reported higher recovery from urine specimens in comparison with blood cultures [3].
Among gram-negative organisms, Klebsiella, represented the majority (22.5%) followed by E. coli (13.4%). On the other hand, CONS (12.5%) was the most common gram-positive pathogen.
These results were similar to the results reported by other researchers studying bacterial strains in Egypt [15, 17] as well as from countries other than Egypt. Osifo, and Aghahowa from Nigeria reported that E. coli and Klebsiella pneumoniae were the most frequently isolated pathogens [18]. However, others reported a higher level of E. coli than Klebsiella spp. [3, 19] and S. aureus was much higher than CONS unlike our study [3]. The high prevalence of CONS was justified by Basiri and coworkers, who stated that it could be the overuse of invasive devices with repeated manipulation by healthcare workers and inadequate infection control measures [20].
As regards the distribution of pathogens among the different clinical specimens in the present work, CONS and Klebsiella spp. were the most frequently isolated from blood cultures. Man et al. from Romania also stated that CONS were the most commonly isolated pathogens from blood culture in their study; however, E. coli came before Klebsiella spp. as a cause of bacteremia [21].
In this study, E. coli and Klebsiella spp. were the main pathogens recovered from urine. Similarly, Duffa et al. [22] reported that E. coli and Klebsiella spp. were highly encountered pathogens in urine. As for the predominating pathogens in wound specimens, Klebsiella, Pseudomonas, and Acinetobacter spp. were highly recovered organisms in the current research. Ibrahim [23] from Saudi Arabia noticed that most the common wound pathogens were Proteus mirabilis followed by Klebsiella pneumoniae. However, in a research by Magdy and colleagues [24], S. aureus was the most common followed by Pseudomonas aeruginosa, Klebsiella pneumoniae, and E. coli.
The difference between the current study and other studies regarding type and frequency of pathogens could be linked to several factors like environmental conditions, health practices, patient conditions, personal hygiene, number of patients involved in each study, and laboratory procedures [3].
The highest percentage of resistance among gram-positive organisms was exhibited towards penicillin (89.5%) followed by erythromycin (83.98%) and cefoxitin (76.52%). Resistance to vancomycin was minimal (2.62%) among gram-positive organisms while no resistance was noted against linezolid (0%). Hove et al. [25] reported that the highest rates of resistance were observed against penicillin (90.0%) and oxacillin (64.0%). The overall resistance towards penicillin and cefoxitin among staphylococcal isolates of Magdy and colleagues [24] from Egypt was in agreement with the present study. However, their S. aureus isolates displayed higher resistance opposite to the current study where CONS was the species with higher resistance. Moreover, their results were much higher as regards vancomycin resistance which displayed resistance rates of 32.4% and 41.2% by S. aureus isolates and CONS respectively [24]. Results of Shebl and Mosaad [3] from Egypt were in contrast to the current study as regards vancomycin and linezolid with a resistance of 10.8% and 11.3%, respectively. However, the results of other researchers regarding vancomycin and linezolid were in favor to that obtained in the present study where Al-Zoubi and his colleagues reported that all their S. aureus isolates were 100% susceptible to vancomycin [26]. Also, Basak et al. [11] and Mahmoud et al. [27] reported 100% susceptibility to both vancomycin and linezolid. The higher antibiotic resistance rates reported by the above-mentioned researches in comparison to the current results might be attributable to inconvenient use of antimicrobials, geographic and socioeconomic variations, sampling biases, and dissimilar patients’ characteristics [28].
As regards Enterococci, the overall resistance pattern was comparable to that reported by Said and Abdelmegeed [29] with the exception of the higher linezolid resistance reported (9.7%) in their study. Likewise, the resistance pattern of ciprofloxacin, erythromycin, gentamicin, and linezolid agrees with that reported by Zalipour and coworkers [30]. Increased resistance to macrolides and quinolones among enterococcal clinical isolates might be attributed to their massive use for the treatment of enterococcal infections [31, 32].
In the present study, gram-negative isolates exhibited high resistance to almost all the used antibiotic classes with the least frequency recorded against nitrofurantoin (52.5%), amikacin (58.01%), followed by imipenem (59.78%) and meropenem (61.82%). All isolates of Pseudomonas and Acinetobacter showed 100% susceptibility to colistin so it can be considered a good therapeutic option [11]. These findings coincide well—with very few exceptions—with those of Eldomany and Abdelaziz [33] from Egypt who reported high antibiotic resistance against their tested isolates of Acinetobacter, Pseudomonas, Klebsiella, Enterobacter, and E. coli from cancer patients.
It is worthy to point to the fact that the high level of resistance observed among the gram-negative organisms in the current study agrees well with the results reported by other researchers [33,34,35]. Such elevated resistance in Enterobacteriaceae may be attributed to β-lactamase activity [36].
Generally, the resistance patterns of Acinetobacter and Proteus in the current research were in concordance with Ibrahim [23], although E. coli isolates in Ibrahim’s study displayed similar results as regards amikacin, gentamycin, imipenem, and piperacillin/tazobactam but with much lower resistance for the rest of antibiotics. Regarding Pseudomonas and Klebsiella, both showed lower resistance rates in contrast to the present study [23]. Several causes can be responsible for the increased incidence of drug-resistance detected in the present study. The prime reason may be the common practice in Egypt where almost all patients—before hospital admission—take diverse antibiotics either prescribed by doctors or self-medication due to over-the-counter antibiotics administered mostly in an improper dose and for an inadequate period [37, 38]. Other potential causes are the geographical divergence as well as the genetic variations among pathogens from different studies. But unfortunately, data about the molecular characterization of the strains included in the current study are not available.
It is obvious that the obtained results in the current study reflected the high prevalence of multidrug resistance especially among gram-negative pathogens. Klebsiella displayed the highest degree of multidrug-resistance (87.84%) followed by Acinetobacter (83.59%). E. coli and Pseudomonas spp. showed almost identical levels of multidrug-resistance (73.68%, 72.02%) respectively, while Proteus and Enterobacter spp. isolates exhibited the lowest resistance among all the gram-negative pathogens.
There is a tremendous increase in MDR gram-negative bacteria in hospitals and especially in the intensive care units (ICU). Such resistance is most notable in ICUs due to the unrestrained usage of antibiotics in ICU in comparison to other hospital departments and most of these infections were caused by gram-negative bacilli [39].
It is important to note that the data presented in this study provide a general overview of the current horrifying situation in the hospital under study. This implicates that an action has to be taken to stop this catastrophe by starting an effective action plan for containment.
