Antimicrobial resistance among GLASS pathogens in Morocco: an epidemiological scoping review

Background Monitoring of antimicrobial resistance (AMR) is of great importance due to the frequency of strains becoming increasingly resistant to antibiotics. This review, using a public health focused approach, which aims to understand and describe the current status of AMR in Morocco in relation to WHO priority pathogens and treatment guidelines. Methods PubMed, ScienceDirect and Google Scholar Databases and grey literature are searched published articles on antimicrobial drug resistance data for GLASS priority pathogens isolated from Morocco between January 2011 and December 2021. Articles are screened using strict inclusion/exclusion criteria. AMR data is extracted with medians and IQR of resistance rates. Results Forty-nine articles are included in the final analysis. The most reported bacterium is Escherichia coli with median resistance rates of 90.9%, 64.0%, and 56.0%, for amoxicillin, amoxicillin-clavulanic acid, and co-trimoxazole, respectively. Colistin had the lowest median resistance with 0.1%. A median resistance of 63.0% is calculated for amoxicillin-clavulanic acid in Klebsiella pneumonia. Imipenem resistance with a median of 74.5% is reported for Acinetobacter baumannii. AMR data for Streptococcus pneumonie does not exceed 50.0% as a median. Conclusions Whilst resistance rates are high for most of GLASS pathogens, there are deficient data to draw vigorous conclusions about the current status AMR in Morocco. The recently join to the GLASS system surveillance will begin to address this data gap. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07412-4.


Background
Antimicrobial resistance (AMR) is increasingly recognized as a global public health issue by leading to a high rate of morbidity and mortality [1,2]. By 2050, the global mortality will have attributed to AMR that could reach 10 million per year; this will pose a significant threat to the global economy if measures are not taken to curb the problem [3]. The antimicrobials misuse and abuse in veterinary and human medicine have accelerated the growing worldwide phenomenon of AMR [4][5][6]. Moreover, the use of antimicrobials in the food chain endangers sustainable food production and food security [7].
In October 2015, the World Health Organization (WHO) launched the Global Antimicrobial Resistance Surveillance System (GLASS), as a necessary contribution to the global action plan against AMR. Morocco joined GLASS system by the end of 2018 [8]. Recent Nejjari et al. BMC Infectious Diseases (2022) 22:438 AMR data collected from two million patients over 66 countries show high rates of resistance among antimicrobials frequently used to treat common bacterial infections [9]. The main AMR profiles are defined as those identified by WHO as "priority pathogens" for the public health significance. There are eight organisms: Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Streptococcus pneumoniae, Salmonella spp., Shigella spp., and Neisseria gonorrhoeae [9] (Additional file 2: Appendix 1). Pathogen-antimicrobial combinations under GLASS surveillance include penicillins, third-and fourth-generation cephalosporins, carbapenems, fluoroquinolones, aminoglycosides, tetracyclines, polymyxins, macrolides, and co-trimoxazole.
It is well known that E. coli and K. pneumoniae are the most common pathogens of urinary tract infections (UTIs), which are one of the most common bacterial infections [10][11][12][13]. Uropathogenic E. coli strains have a range of adhesins that allow the bacteria to aggregate and adhere to the cellular surfaces [11,14]. In addition to UTIs, K. pneumonia causes a variety of infectious diseases, including bacteremia, pneumonia, and liver abscesses. K. pneumoniae multidrug-resistant strains are closely related to the antibiotic resistance genes encoded by plasmid [15,16]. The extensive use and misuse of carbapenems to treat diseases and infections caused by multidrug-resistant gram-negative bacteria contribute to the evolution of plasmid-mediated carbapenemases [17]. A. baumannii and S. aureus are some of the more common opportunistic pathogens which cause community and nosocomial infections. Unfortunately, the number of multidrug-resistant A. baumannii isolates has increased significantly [18,19]. Resistance to antibiotics is widespread in S. aureus, which methicillin-resistant S. aureus (MRSA) are the most important clinically [20].
S. pneumoniae is an opportunistic pathogen causes pneumonia, meningitis, sepsis, bacteremia, and otitis media, especially in individuals with underdeveloped, weakened, and or deteriorating immune systems. S. pneumoniae has developed increased resistance to multiple classes of antibiotics [21,22]. Salmonella belongs to the family Enterobacteriaceae and causes especially gastroenteritis, bacteraemia and enteric fever [23]. Antimicrobial resistance in Salmonella strains is a serious health problem worldwide. Mechanisms of Salmonella resistance are related especially to genes encoding proteins related to drug transport [24,25]. Shigella causes especially acute gastrointestinal infections and is increasingly becoming highly drug resistant [26][27][28]. In the same line, Neisseria gonorrhoeae has developed resistance to every antibiotic currently approved for treatment [29].
In Morocco, recently, the Ministry of Health creates the national coordination unit and the technical committee for the surveillance of AMR. However, earliest studies highlighted the resistance seriousness of microorganisms to antibiotics [30][31][32]. Hitherto, however, these data have not been combined to provide a perspective at a national level. This review aims to describe the recent published AMR data from Morocco and gives a summary of key AMR patterns in the country by focusing on the organisms identified by WHO-GLASS.

Sources of information and search strategies
PubMed, SciencDirect, and the Google Scholar were searched for papers from January 1, 2011 to December 20, 2021. Search strategy in PubMed database was performed on MeSH terms (see Additional file 2: Appendix 2). In addition, we researched related reviews and references for relevant studies. The design of this proposed scoping review methodology was informed by Arksey and O'Malley's framework [33] and The Joanna Briggs Institute Reviewers' Guidance [34]. The selection of articles for review is done by three-stage method whereby the title alone was examined, followed by looking at the abstract, and then examining the whole article ( Fig. 1).

Eligibility: inclusion and exclusion criteria
All original articles written in English or French languages reporting the prevalence of antibiotic resistance in bacteria strains isolated from humans by standard laboratory tests are included.
The inclusion criteria include: • Reports on AMR in humans from Morocco, • Information about antibiotic resistance of at least one bacterium, • The denominator as total isolates clearly described for population-based studies, • Correspondence and abstracts published with sufficient information on methodology and results.
The exclusion criteria include reports published before 2011, studies only focused on HIV or tuberculosis without AMR information, reviews, and studies without information on total studied isolates.

Article quality assessment
The quality of each article is assessed using the modified critical appraisal checklist recommended by the Joanna Briggs Institute [35] (Additional file 2: Appendix 3). Quality assessment of studies was performed by two reviewers independently. Disagreements were resolved by a consensus-based discussion. Nine items are used as quality criteria for assessing the design, details of sample collection, processing and reporting on AMR methodologies.

Data extraction and analysis
Data extraction is done using a predesigned and pretested database, developed for the purpose of this review using Microsoft Excel 2016 spreadsheet (Additional file 2: Appendix 4). Data extracted are name of first author, publication date, sample size, time and location of study, laboratory methodological information (pathogen identification and antimicrobial susceptibility testing methodology) and antibacterial resistance data.
Intermediate susceptibility, where reported, is considered as resistant. Where susceptibility rates are reported, without resistance rates, the resistance rates are calculated as the inverse of the susceptibility rates. Two authors independently collected data.

Data and study characteristics
In total, 14,662 articles are collected from the initial literature search, and from them only 61 are eligible for data abstraction (Fig. 1). However, after full assessment, 12 articles are excluded due to data overlapping or duplication [36][37][38] and for difficulties to abstract data [39][40][41][42][43][44][45][46][47]. Finally, 49 papers fulfilling the inclusion criteria are included in the final analysis. Characteristics of included studies are summarized in Table 1.
Of the 49 included studies, 13 reported isolates from children only, while 14 not reported age of patients. The majority of included studies [38] used the disk diffusion method as the antibiotic-susceptibility test. Some studies used agar dilution and broth dilution combined, referred to as MIC testing for the analysis. The most commonly reported organism was E. coli, with AMR data reported by 22 papers. In contrast, AMR data is reported by one paper for Shigella spp. [48], one paper for N. gonorrhoea [49] and two papers for Salmonella spp. [48,50] (Table 1).

Acinetobacter baumannii
Thirteen papers reported data for A. baumannii (Table 1). Except for El Mekes et al. study [55], all papers reported imipenem resistance with a median 74

Salmonella spp.
Two papers report resistance data for Salmonella spp. in humans [48,50]. In the study of Benmessaoud et al. [48], resistance to 3CG, 4CG, imipenem and amikacin is not detected. Resistance to tetracyclines, fluoroquinolones (ciprofloxacin and levofloxacin) and co-trimoxazole is reported as 60.0%, 20.0% and 40.0%, respectively. The results reported by Ed-Dra et al. [50] show that 84.6% (22/26) of the Salmonella infantis strains were susceptible to all of the 14 antibiotics tested. Three strains are resistant to tetracycline, two strains had low-level β-lactam resistance and one strain is resistant to streptomycin and sulfonamide.

Shigella spp.
One study reports AMR data for Shigella spp. among nine isolates including six S. sonnei [48]. No resistance found to 3CG, fluoroquinolones and imipenem. Resistance higher than 50% is reported to tetracycline (55.5%) and co-trimoxazole (66.7% for all strains and 83.3% for S. sonnei).

Neisseria gonorrhoeae
One study reports AMR data for N. gonorrhoeae among 72 isolates recruited from 171 men [49].

Discussion
Over the last decade in Morocco, there has been no comprehensive review dealing with the AMR prevalence using the global antimicrobial resistance surveillance system (GLASS). This attempt seeks, hopefully, to fill the gap and clarify the AMR status in the country's regions. The AMR data depicts high heterogeneity due to unstandardized laboratory methods, clinical conditions, and a few isolates. This makes drawing firm conclusions highly challenging. However, resistance rates to several key clinically important antibiotics are found to be alarmingly high.
To this end, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards are recommended over the Clinical and Laboratory Standards Institute (CLSI) guidelines. Moreover, improved access to quality assurance is needed to enhance the current WHO initiative, and scale up the global antimicrobial surveillance system (GLASS) based on country-specific priority pathogens [9].
In a recent systematic review conducted in the MENA region [68], it is shown that the lack of consistency and harmonization in the regional surveillance system is not a prerogative of the Middle East, as is the case in developed countries.
The most frequently GLASS pathogens belong to the Enterobacteriaceae family (E. coli and K. pneumoniae), A. baumannii, and S. aureus. They have been described in most of selected papers. Other systematic reviews, conducted on AMR in the Middle East [68] and Africa [69], have reported the same results. Concerning Shigella spp. and N. gonorrhoeae, each has been cited by only one paper. Shigella spp. is the second leading cause of diarrheal mortality, which accounts for 13.2% of diarrheal deaths globally [70] whereas, N. gonorrhoeae causes high levels of morbidity in LMICs, and shows the rapid development of AMR [8,9]. Enterobacterales are a large order of different types of bacteria that commonly cause infections both in healthcare settings and communities. This family represented especially by E. coli and K. pneumoniae can produce extended-spectrum beta-lactamases (ESBLs) Enzymes. The latter break down some commonly used antibiotics such as penicillins and cephalosporins, which render them inefficient [71]. The WHO has recently published a global priority list of antibiotic-resistant bacteria, which includes ESBL-producing Enterobacteriaceae and carbapenemase-producing Enterobacteriaceae [8,9]. Carbapenem belong to the category of β-lactams, which has a broader spectrum of activity. It bind to the bacterial cell wall and inhibits growth. It also results in damage to the cell wall, which frequently leads to cell lysis and death [13,72,73]. Carbapenem resistance may be caused by different mechanisms, one of them being inducible overexpression of chromosomal cephalosporinases combined with porin loss [74,75]. Enterobacteriaceae with ESBL/ carbapenemase genes are bestowed with highly multidrug resistance among humans, animals, and food chains [76]. Moreover, careless use of these antibiotic classes would co-select for resistance genotypes against the others [76].
The proportion of AMR driven from this review is alarming. The highest proportion of studies on both E. coli and K. pneumoniae are related to UTIs. Such cases require more complex treatments [9]. Such infections might require hospitalization and intravenous injection of carbapenem antibiotics. In this review, the carbapenem-resistance proportion among GLASS Enterobacteriaceae appears like other reports from Africa [69] and the Middle East [68], but higher than those described in most European countries [77]. In this context, the prevalence of carbapenemase-producing K. pneumoniae and E. coli, per 10,000 hospital admissions, presents an average of 1.3 (6.0 in Italy, 0.02 in Norway). The incidence per 100,000 hospital patient-days ranged from 17.3 in Greece to 0.09 in Lithuania, with a mean of 2.5 across all the countries. In China, the overall carbapenem-resistant Enterobacteriaceae infection incidence per 10,000 discharges was 4.0 and varies significantly by region [78]. However, no carbapenem-resistant Enterobacteriaceae is found in a recent systematic review from Cambodia [79]. Carbapenemases have a global distribution, but substantial variability exists at the regional and continental levels.
Recently, different products are under evaluation and over thirty antibiotics are active against the most dangerous pathogens included in the WHO's priority pathogens [80,81]. Many of them consist of combinations of new β-lactams and β-lactam inhibitors. d-mannose derivatives and glycomimetics are reported as a promising, valuable, effective, feasible and cost-effective way to treat UTIs especially, urgent clinical trials [82,83].
In the past decade, numerous review papers have highlighted the rising problem of colistin resistance worldwide, especially with E. coli, K. pneumonia, and A. Baumanii in the human community [16,68,69,[84][85][86][87]. Current and emerging colistin resistance may be explained by its high usage in the animal field, and this not only as an infection-healing drug but also as a growth promoter and protective agent [88]. Following this study, several reviews have also reported high 3GC, co-trimoxazole, fluoroquinolones, and gentamicin resistance among E. coli and K. pneumoniae isolates [68,69,87].
In the current review, the pathogens isolated from humans such as Salmonella spp., Shigella spp., and N. gonorrhoeae are understudied in the Morocco context. However, AMR in Salmonella spp. from foods and environmental sources is mentioned by several studies [89,90]. Such finding is also revealed by other systematic reviews in other countries [68,69]. On the other hand, N. gonorrhoeae is known for its high resistance to ciprofloxacin [91,92]. Of note, ciprofloxacin, which is used to treat gonococcal infections, done by, was replaced by ceftriaxone in the Moroccan context [49]. This decision is sustained by previous studies [93] stating that penicillin, tetracycline, and ciprofloxacin should not be used for N. gonorrhoeae management in Morocco. For Salmonella spp., the prevalence of fluoroquinolone resistance has exceeded 30% in many areas of the Arab World [94]. This remains significantly high when compared with the Moroccan context, where it does not surpass 20%. As recommended by Ranjbar et al. [28] a clear virulence gene profile of Shigella may lead to have an accurate diagnosis and a definite treatment relating to different pathogenic strains. In a recent study on Shigella in Morocco, the dual contribution of SfGtr4 and SfPgdA genes to the pathogenicity and the regulation biofilm formation by S. flexneri is demonstrated [95].
The epidemiology of S. aureus, especially that of MRSA, has shown a rapid evolution over the last years. Global surveillance has emphasized that MRSA represents a problem in all countries showing an increase in the mortality and need to use last-resource antibiotics [8,9,96]. The proportion of MRSA (30%) reported in this review is still higher than that mentioned in the European countries (16.9%) [97], but lower than those reported in Asia (28-70%) [98], and Africa (53%) [99]. While the treatment options for MRSA are still limited, there are several new antimicrobials under development [100]. S. pneumoniae is reported as a major cause of communityacquired pneumonia, meningitis, sepsis, bacteremia, and otitis media [101,102]. A decline in susceptibility of S. pneumoniae to commonly used beta-lactams, fluoroquinolones, and macrolides is mentioned by several studies [101,103,104].
Although the findings of this study may seem useful, some limitations must be considered when the interpretation of the results is required. The strict focus on GLASS bacteria might have led to oversight of important pathogens like Helicobacter pylori [105,106], and Pseudomonas aeruginosa [107,108], which are of significate public health concern in AMR. The Validity and generalizability of the findings to the entire country's regions might be affected by the clinical-based, cross-sectional study design of the published papers, mainly collected from Casablanca and Marrakech cities. Besides, there is high variability among the criteria relevant to methodology and interpretation. This is consonant with the data depicted elsewhere in recent similar reviews [68,69,79,87]. There are some calls to adopt standardized AMR data presented in published papers, wishing to make the findings interpretable and comparable from the perspective of scarce homogeneity [109]. Despite these limitations, the high proportion of AMR detected in this review has a certain degree of validity.

Conclusions
In summary, this review highlights that data on AMR in Morocco are limited but improving. Overall, there are significant similarities in AMR tendency in comparison with other countries worldwide. The recent joining of Morocco to the GLASS system will improve the accuracy, quality, and comparability of data collected on AMR.