Multidrug resistance Acinetobacter species at the intensive care unit, Aseer Central Hospital, Saudi Arabia: A one year analysis

Carbapenem-resistant Acinetobacter baumannii infections: Antimicrobial resistance patterns and risk factors for acquisition in a Kenyan intensive care unit

Objectives

Multidrug-resistant (MDR) Acinetobacter baumannii (AB), especially carbapenem-resistant (CR) strains, presents a significant challenge in intensive care units (ICUs) but surveillance data in many resource-constrained countries is inadequate. Here, we determined the prevalence of MDRAB and risk factors for infection and mortality in ICU-admitted patients.

Methods

A cross-sectional study among 132 consecutive patients between July 2019 and July 2020, with infected patients followed for 30 days from sample collection to ICU discharge/death. Blood, urine, and tracheal aspirate samples were processed following the standard bacteriological procedures. Isolate identity and antimicrobial susceptibility were elucidated by VITEK 2 Compact system.

Results

The prevalence of MDRAB was 22.7% (30/132), mostly from urine samples (12.1%, 16/132), and dominated by CRAB (83.3%) that were colistin-nonresistant and exhibited high multiple antibiotic resistance indices, ranging from 0.64-0.91. Risk factors for infection were occupation (adjusted odds ratio = 4.41, P = 0.016) and interhospital referral status (adjusted odds ratio = 0.14, P = 0.001). ICU mortality was 20% (6/30).

Conclusion

Our findings underpin the need for strict adherence to and evaluation of infection prevention and control, and continuous surveillance of CRAB in ICU, especially among the risk groups, in the current study setting and beyond.

The Prevalence of Multidrug-Resistant Acinetobacter baumannii and Its Vaccination Status among Healthcare Providers

There is growing concern among healthcare providers worldwide regarding the prevalence of multidrug-resistant Acinetobacter baumannii (A. baumannii). Some of the worst hospital-acquired infections, often in intensive care units (ICUs), are caused by this bacterial pathogen. In recent years, the rise in multidrug-resistant A. baumannii has been linked to the overuse of antimicrobial drugs and the lack of adequate infection control measures. Infections caused by this bacterial pathogen are the result of prolonged hospitalization and ICU stays, and they are associated with increased morbidity and mortality. This review outlines the epidemiology, risk factors, and antimicrobial resistance associated with A. baumannii in various countries, with a special focus on the Kingdom of Saudi Arabia. In response to the growing concern regarding this drug-resistant bacteria, fundamental information about its pathology has been incorporated into the development of vaccines. Although these vaccines have been successful in animal models, their effectiveness in humans remains unproven. The review will discuss the development of A. baumannii vaccines, potential related obstacles, and efforts to find an effective strategy against this pathogen.

Prevalence and Etiology of Community- and Hospital-Acquired Pneumonia in Saudi Arabia and Their Antimicrobial Susceptibility Patterns: A Systematic Review

(1) Background and Objectives: Pneumonia is a major cause of morbidity and mortality worldwide, including in Saudi Arabia, and the prevalence and etiology of the disease varies depending on the setting. The development of effective strategies can help reduce the adverse impact of this disease. Therefore, this systematic review was conducted to explore the prevalence and etiology of community-acquired and hospital-acquired pneumonia in Saudi Arabia, as well as their antimicrobial susceptibility. (2) Materials and Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations were followed for this systematic review. Several databases were used to perform a thorough literature search, and papers were then assessed for eligibility by two independent reviewers. The Newcastle-Ottawa Scale (NOS) was used to extract the data from the relevant research and evaluate its quality. (3) Results: This systematic review included 28 studies that highlighted the fact that gram-negative bacteria, particularly Acinetobacter spp. and Pseudomonas aeruginosa, were the common cause of hospital-acquired pneumonia, while Staphylococcus aureus and Streptococcus spp. were responsible for community-acquired pneumonia in children. The study also found that bacterial isolates responsible for pneumonia showed high resistance rates against several antibiotics, including cephalosporins and carbapenems. (4) Conclusions: In conclusion, the study found that different bacteria are responsible for community- and hospital-acquired pneumonia in Saudi Arabia. Antibiotic resistance rates were high for several commonly used antibiotics, highlighting the need for rational antibiotic use to prevent further resistance. Moreover, there is a need to conduct more regular multicenter studies to assess etiology, resistance, and susceptibility patterns of pneumonia-causing pathogens in Saudi Arabia.

Prevalence of Multidrug-Resistant Pathogens Causing Bloodstream Infections in an Intensive Care Unit

Introduction

Bloodstream infections are the most severe infections that cause the highest mortality rate, especially in patients admitted to the intensive care unit (ICU). In this study, we aimed to analyze the distribution, resistance patterns and prevalence of MDR (multidrug-resistant) pathogens isolated in blood samples collected from patients with severe invasive infections hospitalized in the ICU.

Methods

A retrospective study of bacterial pathogens was performed on 490 patients admitted to the ICU between 2017 and 2020. The resistance patterns were analyzed using Vitek 2 Compact system.

Results

In total, 617 bacterial isolates were obtained. Four hundred and twenty-seven isolates (69.21%) were Gram positive and 190 isolates (30.79%) were Gram negative bacteria. The most frequently isolated micro-organisms identified in the blood samples for the entire period (2017-2020) were Coagulase-negative staphylococci (CoNS) (318-51.54%), followed by Klebsiella pneumoniae (70-11.34%), Methicillin-Resistant Staphylococcus aureus (MRSA) (58-9.40%), Acinetobacter baumannii (45-7.29%) and Enterococcus faecalis (42-6.80%). The number of Klebsiella pneumoniae strains significantly increased in 2020, compared to the previous year (p < 0.05). The Acinetobacter baumannii prevalence was significantly higher in the age group of 20-64 years (10.89%) and over 65 years (3.53%) (p < 0.001). The difference between the prevalence of CoNS in the elderly (67.84%) and in adults (20-64 years) (52.47%) was also statistically significant (p < 0.001). High rates of MDR were found for Acinetobacter baumannii (97.77%), Pseudomonas aeruginosa (65%), Klebsiella pneumoniae (50%), Enterococcus faecalis (47.61%) and MRSA (46.55%). More than 60% of the Klebsiella pneumoniae strains were found to be resistant to carbapenems.

Conclusion

The study revealed an alarming prevalence of MDR strains isolated in blood samples of the patients admitted to the ICU, indicating the necessity of consistent application of the measures to control.

Evaluation of culturable 'last-resort' antibiotic resistant pathogens in hospital wastewater and implications on the risks of nosocomial antimicrobial resistance prevalence

Antimicrobial resistance has been recognized as an important emerging environmental pollutant. 'Last-resort' antibiotics including tigecycline, polymyxin E, daptomycin, vancomycin and linezolid are the 'last line of defence' for antibiotic resistant pathogen infections. Therefore, the presence of 'last-resort' antibiotic resistant pathogens in hospital environments and the nosocomial transmission of 'last-resort' antibiotic resistance poses a grave threat to the well-being of patients. In this work, the extent of resistance to 'last-resort' antibiotics in culturable pathogens in hospital wastewater was investigated. Resistance to 'last-resort' antibiotics were quantified for 1384 culturable Enterobacteriaceae, Enterococcus, Staphylococcus, and Pseudomonas strains. With these investigations, several significant findings were made: (1) a very high level of resistance to 'last-resort' antibiotics was found; (2) multiple resistance to antibiotics, including 'last-resort' antibiotics, was prevalent; (3) a high level of 'last-resort' antibiotic resistance phenotype-genotype inconsistency was found, suggesting knowledge gap for resistance mechanisms; 4) tet(X4)-containing tigecycline-resistant Gram-positive pathogens were found for the first time; 5) wastewater treatment processes are effective in preventing the release of 'last-resort' antibiotic resistant pathogens to the environment. This investigation reveals the severe situation on 'last-resort' resistance in the hospital environment, and implies high risk for nosocomial transmission of 'last-resort' antibiotic resistant pathogens.

Zoonotic Bacteria Harboring in Goat Intestine: A One Health Perspective

The risk of zoonosis transmission when handling livestock or animal products is substantial, ‘One Health’ interventions should be an effective strategy for the control of many zoonotic bacteria. In this study, 26 fresh fecal samples from 2 clinically healthy goats were collected at different day ages to survey goat-borne zoonotic bacterial infection, and 19 fresh fecal samples from diarrhetic goats were tested to evaluate the possible role of zoonotic pathogens in goat diarrhea. Following all samples were analyzed by Metagenomic Sequencing, a total of 20 kinds of zoonotic bacteria were screened from healthy goats, and 11 (55%) of them were infection mainly during the preweaned period. Of the 19 fresh fecal samples from diarrhetic goats, all were confirmed to be zoonotic bacterial infection positive (range from 11 to 12 species). After comparison with healthy samples of the same or similar day-age goats, it was found that Lactococcus garvieae, Helicobacter pylori, Klebsiella pneumoniae, Shigella sonnei, Shigella boydii, Campylobacter coli, Salmonella enterica, Acinetobacter baumannii, Shigella flexneri, Shigella dysenteriae and Clostridium perfringens and Campylobacter fetus were highly increased incases in some diarrheic cases, while the remains had no significant change. The results suggest that goats may act as a reservoir for many zoonotic bacteria, and some of them may be associated with goat intestinal inflammation.

Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Isolated from Intensive Care Unit Patients in Jordanian Hospitals

Acinetobacter baumannii is a common cause of healthcare-associated infections (HAI) worldwide, mostly occurring in intensive care units (ICUs). Extended-spectrum beta lactamases (ESBL)-positive A. baumannii strains have emerged as highly resistant to most currently used antimicrobial agents, including carbapenems. The most common mechanism for carbapenem resistance in this species is β-lactamase-mediated resistance. Carbapenem-hydrolyzing class D oxacillinases are widespread among multidrug-resistant (MDR) A. baumannii strains. The present study was conducted to determine the presence and distribution of bla_OXA genes among multidrug-resistant A. baumannii isolated from ICU patients and genes encoding insertion sequence (IS-1) in these isolates. Additionally, the plasmid DNA profiles of these isolates were determined. A total of 120 clinical isolates of A. baumannii from various ICU clinical specimens of four main Jordanian hospitals were collected. Bacterial isolate identification was confirmed by biochemical testing and antibiotic sensitivity was then assessed. PCR amplification and automated sequencing were carried out to detect the presence of bla_OXA-51, bla_OXA-23, bla_OXA-24, and bla_OXA-58 genes, and ISAba1 insertion sequence. Out of the 120 A. baumannii isolates, 95% of the isolates were resistant to three or more classes of the antibiotics tested and were identified as MDR. The most frequent resistance of the isolates was against piperacillin (96.7%), cephalosporins (97.5%), and β-lactam/β-lactamase inhibitor combinations antibiotics (95.8%). There were 24 (20%) ESBL-producing isolates. A co-existence of bla_OXA-51 gene and ISAba1 in all the 24 ESBL-producing isolates was determined. In addition, in the 24 ESBL-producing isolates, 21 (87.5%) carried bla_OXA-51 and bla_OXA-23 genes, 1 (4.2%) carried bla_OXA-51 and bla_OXA-24, but all were negative for the bla_OXA-58 gene. Plasmid DNA profile A and profile B were the most common (29%) in ESBL-positive MDR A. baumannii isolates while plasmid DNA profile A was the most common in the ESBL-negative isolates. In conclusion, there was an increase in prevalence of MDR-A. baumannii in ICU wards in Jordanian hospitals, especially those having an ESBL phenotype. Thus, identification of ESBL genes is necessary for the surveillance of their transmission in hospitals.

Emergence of bla TEM, bla CTX-M, bla SHV and bla OXA genes in multidrug-resistant Enterobacteriaceae and Acinetobacter baumannii in Saudi Arabia

Multidrug-resistant (MDR) patterns due to extended-spectrum β-lactamase (ESBL) production in pathogenic bacteria are now becoming prevalent in hospitals worldwide, posing a public health challenge. The aim of the present study was to determine the antibiotic susceptibility patterns and distribution of the bla _TEM, bla _CTX-M, bla _SHV and bla _OXA ESBL resistance genes in MDREnterobacteriaceae and Acinetobacter baumannii (A. baumannii). A cross-sectional study was conducted between September 2017 and August 2018 in the King Abdullah Hospital (Bisha, Saudi Arabia). Bacterial isolates were collected from the clinical samples of patients; these were identified and screened for ESBL production and their antibiotic susceptibility was examined using standard microbiology methods. Multiplex-PCR runs were performed to identify genes encoding ESBL producers. DNA sequencing analysis was used to identify the specific gene variants. Of the 274 isolates, 173 (63.1%) exhibited MDR patterns to different antibiotics. A. baumannii revealed the highest resistance rates for cefuroxime (100%), gentamicin (88%) and amikacin (86%). Klebsiella pneumoniae (K. pneumoniae) isolates had the highest resistance rates for cefuroxime (98%), aztreonam and trimethoprim/sulfamethoxazole (87% for each). Escherichia coli (E. coli) exhibited high resistance rates for trimethoprim/sulfamethoxazole (92%) and cefuroxime (87%). Of the 173 MDR isolates, 78 (45.1%) exhibited ESBL production. Of these, 88.9% (72/78) carried ESBL genes. The most prevalent gene-encoding isolates were bla _TEM (84.7%), followed by bla _CTX-M (33.3%), bla _SHV (2.7%) and bla _OXA-1 (1.4%). A single bla _TEM gene was predominantly produced by K. pneumoniae (60.7%), A. baumannii (78.9%) and Proteus mirabilis (80%), whereas bla _CTX-M was harbored by E. coli (33.3%). The co-existence of two different genes in a single bacterium was revealed in 22.2% of isolates, commonly between bla _TEM and bla _CTX-M (19.4%). Sequencing analysis revealed that bla _CTX-M-15 and bla _TEM-1 were predominant variants of the bla _CTX-M and bla _TEM genes, respectively. The present study revealed a diversity of ESBL genes in Gram-negative bacterial isolates, with bla _TEM being the most prevalent type. The emergence of various ESBL genes with several co-existing genotypes is alarming, rendering extensive surveillance studies necessary to understand the transmission and epidemiology of such resistant gene-carrying isolates.

Emerging Status of Multidrug-Resistant Bacteria and Fungi in the Arabian Peninsula

Simple Summary

The incidence and developing status of multidrug-resistant bacteria and fungi, as well as their related mortality, is reviewed by a systematic published literature search from nine countries in the Arabian Peninsula. In order to analyse the emerging status and mortality, a total of 382 research articles were selected from a comprehensive screening of 1705 papers. More than 850 deaths reported since 2010 in the Arabian Peninsula due to the infection of multidrug-resistant bacteria and fungi. Multidrug-resistant bacteria Acinetobacter baumannii, Mycobacterium tuberculosis, Staphylococcus aureus, and fungi Candida auris are the most prevalent and causing high deaths. To control these infections and associated deaths in the Arabian Peninsula, continuous preventive measures, accurate methods for early diagnosis of infection, active surveillance, constant monitoring, developing vaccines, eradicating multidrug resistance modulators, and data sharing among countries are required.

Abstract

We aimed to identify the prevalence and emerging status of multidrug-resistant bacteria and fungi and their associated mortality in nine countries in the Arabian Peninsula. Original research articles and case studies regarding multidrug-resistant bacteria and fungi in the Arabian Peninsula, published during the last 10 years, were retrieved from PubMed and Scopus. A total of 382 studies were included as per the inclusion and exclusion criteria, as well as the PRISMA guidelines, from a thorough screening of 1705 articles, in order to analyse the emerging status and mortality. The emerging nature of >120 multidrug-resistant (MDR) bacteria and fungi in the Arabian Peninsula is a serious concern that requires continuous monitoring and immediate preventive measures. More than 50% (n = 453) of multidrug-resistant, microbe-associated mortality (n = 871) in the Arabian Peninsula was due to MDR Acinetobacter baumannii, Mycobacterium tuberculosis and Staphylococcus aureus infection. Overall, a 16.51% mortality was reported among MDR-infected patients in the Arabian Peninsula from the 382 articles of this registered systematic review. MDR A. baumannii (5600 isolates) prevailed in all the nine countries of the Arabian Peninsula and was one of the fastest emerging MDR bacteria with the highest mortality (n = 210). A total of 13,087 Mycobacterium tuberculosis isolates were reported in the region. Candida auris (580 strains) is the most prevalent among the MDR fungal pathogen in the Arabian Peninsula, having caused 54 mortalities. Active surveillance, constant monitoring, the development of a candidate vaccine, an early diagnosis of MDR infection, the elimination of multidrug resistance modulators and uninterrupted preventive measures with enhanced data sharing are mandatory to control MDR infection and associated diseases of the Arabian Peninsula. Accurate and rapid detection methods are needed to differentiate MDR strain from other strains of the species. This review summarises the logical relation, prevalence, emerging status and associated mortality of MDR microbes in the Arabian Peninsula.

Five-year resistance trends in pathogens causing healthcare-associated infections at a multi-hospital healthcare system in Saudi Arabia, 2015-2019

OBJECTIVES

Awareness of antimicrobial resistance (AMR) patterns in a given healthcare setting is important to inform the selection of appropriate antimicrobial therapy to reduce the further rise and spread of AMR as well as the rate of healthcare-associated infections (HAIs) and multidrug-resistant (MDR) organisms. We aimed to describe resistance patterns to several antimicrobial agents in pathogens causing HAIs isolated from patients using data gathered at three private tertiary-care hospitals in Saudi Arabia.

METHODS

Data on trends in AMR among bacteria causing HAIs and MDR events in children and adults at three private hospitals were collected retrospectively (2015-2019) using surveillance data.

RESULTS

Over the 5-year period, 29 393 pathogens caused 17 539 HAIs in 15 259 patients. Approximately 57.3% of patients were female and the mean age was 38.4 ± 16.8 years (81.4% adults, 18.6% children). Gram-negative pathogens were four times more likely to cause HAIs compared with Gram-positive bacteria (79.3% vs. 20.7%). Ranking of causative pathogens in decreasing order was Escherichia coli (42.2%), Klebsiella spp. (16.8%) and Staphylococcus aureus (13.9%). Acinetobacter spp. were the only pathogens to decrease significantly (7% reduction; P = 0.033). The most common resistant pathogens were extended-spectrum cephalosporin-resistant E. coli (37.1%), extended-spectrum cephalosporin-resistant Klebsiella (27.8%), carbapenem-non-susceptible Acinetobacter spp. (19.5%), carbapenem-non-susceptible Pseudomonas aeruginosa (19.2%) and methicillin-resistant S. aureus (18.6%).

CONCLUSION

National collaboration is required by prompt feedback to local authorities to tackle regional differences in AMR. This can help plan timely containment interventions to stop and contain microbial threats and swiftly assess their impact.

Antimicrobial resistance among GLASS pathogens in conflict and non-conflict affected settings in the Middle East: a systematic review

BACKGROUND

In spite of the evident general negative effects of armed conflict on countries' health systems and populations' health outcomes, little is known about similar impacts of conflicts on the spread of antimicrobial resistances (AMR). This review was to address this evidence gap and describe: 1. Patterns of AMR in the Middle East (ME) and resistance profiles of pathogens included in the Global AMR Surveillance System (GLASS) supported by the World Health Organization; 2. Differences in proportions of AMR isolates between conflict and non-conflict countries.

METHODS

A systematic literature review was conducted following PRISMA guidelines and searching five electronic databases. Subject heading and free text were searched for "antimicrobial resistances" and "Middle East", to identify observational studies on AMR published from January 2011 to June 2018. Data were extracted from included articles on a predefined set of variables. Percentages of AMR were analysed as median and interquartile ranges. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 132 articles met the inclusion criteria. Included studies showed heterogeneity in study design, laboratory methods and standards for interpretation of results, and an overall high risk of bias. Main findings were the following: 1. High proportions of carbapenem resistance in Acinetobacter spp. (median 74.2%), and both carbapenem resistance (median 8.1 and 15.4% for E. coli and K. pneumoniae respectively) and ESBL-production (median 32.3 and 27.9% for E. coli and K. pneumoniae respectively) amongst Enterobacteriaceae. S. aureus isolates showed a median methicillin resistance percentage of 45.1%, while vancomycin resistance was almost absent. A median of 50% of the strains of S. pneumoniae showed non-susceptibility to penicillin. 2. Similar trends were observed in conflict and non-conflict affected countries.

CONCLUSIONS

There is a lack of standardization in the methodological approach to AMR research in the Middle East. The proportion of antibiotic resistances among specific GLASS pathogens is high, particularly among Acinetobacter spp.

Frequency and Antibiotic Susceptibility of Pseudomonas aeruginosa and Acinetobacter baumannii Infections in Pediatrics Intensive Care Unit of Imam Ali Hospital, Karaj, Iran During 2017- 2018

Background: Pseudomonas aeruginosa and Acinetobacter baumannii are widely ubiquitous in nature. In addition, they are opportunistic pathogens for humans and the common cause of nosocomial infections. Objective: Due to the increased antibiotic resistance in the treatment of nosocomial infections, this study aimed to evaluate the antibiotic susceptibility pattern of P. aeruginosa and A. baumannii in the pediatrics intensive care unit (PICU). Materials and Methods: Totally, 280 clinical samples from PICU patients were evaluated in this study. The samples were examined for P. aeruginosa and A. baumannii using standard microbiological methods. Finally, the Epsilometer test method was performed to investigate the antibiotic susceptibility pattern of these bacteria. Results: The results revealed a total of 21 isolates (7.5%) of P. aeruginosa and 11 isolates (3.9%) of A. baumannii. P. aeruginosa isolates showed the highest susceptibility to colistin (85.7%) and gentamicin (66.7%) while A. baumannii isolates were more susceptible to colistin (100%), ceftazidime (54.5%), and amikacin (45.5%), respectively. Conclusion: Due to the antibiotic susceptibility patterns of bacterial isolates in the recent study, colistin and gentamicin are recommended for the treatment of P. aeruginosa infections and colistin, ceftazidime, and amikacin are suggested for A. baumannii infections.

Efficacy of Antimicrobials Against Multidrug-Resistant Acinetobacter baumannii from Patients in a Tertiary Care Hospital

Introduction: In just two decades Acinetobacter baumannii has attained considerable importance, evolving from an insignificant organism to a leading pathogen especially in intensive care unit settings globally. Treatment options are already very limited and have almost run out due to the rapid emergence of antimicrobial resistance. Evaluation of antimicrobials that are currently in use to determine their effectiveness against multidrug-resistant (MDR) strains and developing newer options is of utmost importance. We thus set out to determine the efficacy of routinely used antibiotics against MDR A. baumannii. Materials and Methods: This was a cross-sectional study conducted at the Department of Microbiology, Army Medical College, National University of Medical Sciences (Rawalpindi, Pakistan) from December 2015 to June 2016. The organisms were identified on the basis of colony morphology, gram staining, catalase, oxidase, motility test, and API (analytical profile index) 20NE. The organisms were considered to be MDR when the isolate was found to be resistant to at least one agent in more than three antimicrobial groups. Antibiotic sensitivity was determined using the modified Kirby-Bauer disc diffusion method according to Clinical Laboratory Standards Institute (CLSI) guidelines. Results: The 77 isolates were found to have good sensitivity to tigecycline (94.8%) and minocycline (80.5%). Most of the isolates were resistant to other routinely used antibiotics. Conclusion: A few antibiotics, tigecycline and minocycline, are still effective against these MDR A. baumannii. We need to remain up to date regarding the efficacy of antibiotics to effectively treat patients with these MDR bacteria.

Global prevalence of colistin resistance in clinical isolates of Acinetobacter baumannii: A systematic review and meta-analysis

INTRODUCTION

Acinetobacter baumannii antimicrobial resistance is a public health concern in developing and developed countries, especially in the hospital setting. Understanding the antibiotic resistance profile can help to provide better guidelines for the prescription of appropriate antibiotics, reduction of antibiotic resistance, and introducing new and effective treatment options.

METHOD

Using the PRISMA guidelines, databases of PubMed, Embase, and Cochrane Library were searched systematically from January 1, 2000, to January 1, 2018. All statistical analyses were carried out via Comprehensive Meta-Analysis Software Version 2.0 (Biostat, Englewood, NJ). Depending on the heterogeneity test, either random or fix effect models were used for determining the pooled prevalence of drug resistance.

RESULT

A total of 150 studies were included from 41 countries of six different WHO regional offices worldwide. The highest and the lowest rate of resistance were observed for cefotaxime (99%, 95% CI: 95-99.9) in Africa and colistin (1.1%, 95% CI: 0.3-4.5) in Western Pacific, respectively. Lebanon (17.5%, 95% CI: 16-19) and China (12%, 95% CI: 3.5-32.5) had the highest and Germany (0.2%, 95% CI: 0-2.5) had the lowest rate of resistance for colistin.

CONCLUSION

Our analysis showed that prevalence and rate of increased colistin resistance in South-East Asia and Eastern Mediterranean countries are higher than other regions of the world. Therefore, the establishment of appropriate antibiotic usage guidelines should be essential in these countries.

Drug resistance-related microRNAs in osteosarcoma: Translating basic evidence into therapeutic strategies

Although the application of multiple chemotherapy brought revolutionary changes to improve overall survival of osteosarcoma patients, the existence of multidrug resistance (MDR) has become a great challenge for successful osteosarcoma treatment in recent decades. Substantial studies have revealed various underlying mechanisms of MDR in cancers. As for osteosarcoma, evidence has highlighted that microRNAs (miRNAs) can mediate in the processes of DNA damage response, apoptosis avoidance, autophagy induction, activation of cancer stem cells, and signal transduction. Besides, these drug resistance‐related miRNAs showed much promise for serving as candidates for predictive biomarkers of poor outcomes and shorter survival time, and therapeutic targets to reverse drug resistance and overcome treatment refractoriness. This review aims to demonstrate the potential molecular mechanisms of miRNAs‐regulated drug resistance in osteosarcoma, and provide insight in translating basic evidence into therapeutic strategies.

Prevalence of Acinetobacter baumannii in Saudi Arabia: risk factors, antimicrobial resistance patterns and mechanisms of carbapenem resistance

Acinetobacter baumannii is an important opportunistic pathogen due to its capabilities for developing mechanisms of resistance to a wide range of antimicrobial agents including carbapenems. This review described the risk factors, antimicrobial susceptibility and mechanisms of carbapenem resistance of A. baumannii from different geographical regions of Saudi Arabia. Several factors including complexity of intensive care unit (ICU) environments, increased numbers of patients with serious diseases, wide spread gastrointestinal colonization and extensive use of antimicrobial drugs led to a wide prevalence of A. baumannii infections in hospitals in Saudi Arabia. A. baumannii has been noted to be less susceptible to antimicrobials agents, including carbapenems, over time, resulting in the evolution of multidrug-resistant (MDR) strains. Dissemination of MDR A. baumannii is attributed to the extreme use of wide-spectrum antimicrobial drugs in hospitals, cross infection between inpatients, invasive ICU procedures, and hospitalized patients with diabetic and cancer those are under frequent invasive diagnostic and therapeutic interventions. Although an increasing prevalence of colistin and tigecycline resistance has been reported in many hospitals, combinations of these agents with carbapenems or other antibiotics remain the best therapeutic choice and reasonably safe to treat patients with MDR A. baumannii infections. The wide distribution of carbapenem resistant A. baumannii (CRAB) due to several mechanisms with diverse genetic determinants has been documented. Although OXA-23 β-lactamase and OXA-51 β-lactamase are the most common genes responsible for CRAB, other novel genes such as blaVIM, PER-1-like and GES-5 have been discovered in carbapenem resistant strains. The high rates of MDR A. baumannii in Saudi hospitals indicate that extensive investigation into the molecular basis of MDR and developing new therapies of CRAB is needed. Moreover, the development of a local antibiogram database coupled with a nationwide antimicrobial stewardship and infection prevention program might help to improve our knowledge of the resistance patterns of A. baumannii, and in developing a treatment protocol for decreasing the infection burden in Saudi Arabia.

Clinical Antibiotic-resistant Acinetobacter baumannii Strains with Higher Susceptibility to Environmental Phages than Antibiotic-sensitive Strains

Antibiotic-resistant Acinetobacter baumannii is associated with nosocomial infections worldwide. Here, we used clinically isolated A. baumannii strains as models to demonstrate whether antibiotic resistance is correlated with an increased susceptibility to bacteriophages. In this study, 24 active phages capable of infecting A. baumannii were isolated from various environments, and the susceptibilities of both antibiotic-sensitive and antibiotic-resistant strains of A. baumannii to different phages were compared. In our study, a total of 403 clinically isolated A. baumannii strains were identified. On average, the phage infection percentage of the antibiotic-resistant A. baumannii strains was 84% (from 81–86%), whereas the infection percentage in the antibiotic-sensitive A. baumannii strains was only 56.5% (from 49–64%). In addition, the risk of phage infection for A. baumannii was significantly increased in the strains that were resistant to at least four antibiotics and exhibited a dose-dependent response (p-trend < 0.0001). Among all of the A. baumannii isolates, 75.6% were phage typeable. The results of phage typing might also reveal the antibiotic-resistant profiles of clinical A. baumannii strains. In conclusion, phage susceptibility represents an evolutionary trade-off in A. baumannii strains that show adaptations for antibiotic resistance, particularly in medical environments that have high antibiotic use.

Trends in Drug Resistance of Acinetobacter baumannii over a 10-year Period: Nationwide Data from the China Surveillance of Antimicrobial Resistance Program

BACKGROUND

Acinetobacter baumannii has emerged as an important pathogen causing a variety of infections. Using data from the China Surveillance of Antimicrobial Resistance Program conducted biennially, we investigated the secular changes in the resistance of 2917 isolates of A. baumannii from 2004 to 2014 to differ antimicrobial agents.

METHODS

Pathogen samples were collected from 17 to 20 hospitals located in the eastern, central, and western regions of China. Minimum inhibitory concentrations (MICs) were determined by a 2-fold agar dilution method, and antimicrobial susceptibility was established using the 2014 Clinical Laboratory Standards Institute-approved breakpoints. Isolates not susceptible to all the tested aminoglycosides, fluoroquinolones, β-lactams, β-lactam/β-lactam inhibitors and carbapenems were defined as extensively drug resistant.

RESULTS

The rates of nonsusceptibility to common antimicrobial agents remained high (>65%) over the years with some fluctuations to certain agents. The prevalence of imipenem-resistant A. baumannii (IRAB) increased from 13.3% in 2004 to 70.5% in 2014 and that of extensively drug-resistant A. baumannii (XDRAB) increased from 11.1% in 2004 to 60.4% in 2014. The activity of tigecycline was stable with MIC90 ≤4 mg/L against A. baumannii from 2009 to 2014. Susceptibility to colistin remained high (97.0%) from 2009 to 2014. The prevalence of XDRAB increased in all the three surveillance regions over the years and was significantly higher in Intensive Care Unit (ICU) wards than non-ICU wards.

CONCLUSIONS

This longitudinal multicenter surveillance program revealed the nationwide emergence of A. baumannii in China and showed a significant increase in prevalence from 2004 to 2014. High levels of bacterial resistance were detected among samples collected from clinical settings in China, with IRAB and XDRAB being especially prevalent. This study will help to guide empirical therapy and identify at-risk groups requiring more intense interventional infection control measures, while also helping to focus surveillance efforts.