Colony phase variation switch modulates antimicrobial tolerance and biofilm formation in Acinetobacter baumannii.

Carbapenem-resistant Acinetobacter baumannii causes one of the most difficult-to-treat nosocomial infections. Polycationic drugs like polymyxin B or colistin and tetracycline drugs such as doxycycline or minocycline are commonly used to treat infections caused by carbapenem-resistant A. baumannii. Here, we show that a subpopulation of cells associated with the opaque/translucent colony phase variation by A. baumannii AB5075 displays differential tolerance to subinhibitory concentrations of colistin and tetracycline. Using a variety of microscopic techniques, we demonstrate that extracellular polysaccharide moieties mediate colistin tolerance to opaque A. baumannii at single-cell level and that mushroom-shaped biofilm structures protect opaque bacteria at the community level. The colony switch phenotype is found to alter several traits of A. baumannii, including long-term survival under desiccation, tolerance to ethanol, competition with Escherichia coli, and intracellular survival in the environmental model host Acanthamoeba castellanii. Additionally, our findings suggest that extracellular DNA associated with membrane vesicles can promote colony switching in a DNA recombinase-dependent manner.IMPORTANCEAs a WHO top-priority drug-resistant microbe, Acinetobacter baumannii significantly contributes to hospital-associated infections worldwide. One particularly intriguing aspect is its ability to reversibly switch its colony morphotype on agar plates, which has been remarkably underexplored. In this study, we employed various microscopic techniques and phenotypic assays to investigate the colony phase variation switch under different clinically and environmentally relevant conditions. Our findings reveal that the presence of a poly N-acetylglucosamine-positive extracellular matrix layer contributes to the protection of bacteria from the bactericidal effects of colistin. Furthermore, we provide intriguing insights into the multicellular lifestyle of A. baumannii, specifically in the context of colony switch variation within its predatory host, Acanthamoeba castellanii.

Multidrug-resistant pathogens contaminate river water used in irrigation in disenfranchised communities.

OBJECTIVES: The contamination of fresh surface waters poses a significant burden on human health and prosperity, especially in marginalized communities with limited resources and inadequate infrastructure. Here, we performed in-depth genomic analyses of multidrug-resistant bacteria (MDR-B) isolated from Al-Oueik river water that is used for irrigation of agricultural fields in a disenfranchised area that also hosts a makeshift Syrian refugee camp. METHODS: A composite freshwater sample was filtered. Faecal coliforms were counted and extended spectrum cephalosporins and/or ertapenem resistant bacteria were screened. Isolates were identified using MALDI-TOF-MS and analysed using whole-genome sequencing (WGS) to identify the resistome, sequence types, plasmid types, and virulence genes. RESULTS: Approximately 106 CFU/100 mL of faecal coliforms were detected in the water. Four drug-resistant Gram-negative bacteria were identified, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter hormaechei, and Pseudomonas otitidis. Notably, the E. coli isolate harboured blaNDM-5 and a YRIN-inserted PBP3, representing an emerging public health challenge. The K. pneumoniae isolate carried blaSHV-187 as well as mutations in the gene encoding the OmpK37 porin. Enterobacter hormaechei and P. otitidis harboured blaACT-16 and blaPOM-1, respectively. CONCLUSION: This report provides comprehensive genomic analyses of MDR-B in irrigation water in Lebanon. Our results further support that irrigation water contaminated with faecal material can be a reservoir of important MDR-B, which can spread to adjacent agricultural fields and other water bodies, posing both public health and food safety issues. Therefore, there is an urgent need to implement effective water quality monitoring and management programs to control the proliferation of antibiotic-resistant pathogens in irrigation water in Lebanon.

Communicable diseases in northwest Syria in the context of protracted armed conflict and earthquakes.

The earthquakes in Türkiye and Syria in February, 2023, have caused further devastation in northwest Syria-an area already affected by protracted armed conflict, mass forced displacement, and inadequate health and humanitarian provision. The earthquake damaged infrastructure supporting water, sanitation, and hygiene, and health-care facilities. The disruptions to epidemiological surveillance and ongoing disease control measures resulting from the earthquake will accelerate and expand ongoing and new outbreaks of many communicable diseases including measles, cholera, tuberculosis, and leishmaniasis. Investing in existing early warning and response network activities in the area is essential. Antimicrobial resistance, which had already been an increasing concern in Syria before the earthquake, will also be exacerbated given the high number of traumatic injuries and breakdown of antimicrobial stewardship, and the collapse of infection prevention and control measures. Tackling communicable diseases in this setting requires multisectoral collaboration at the human-animal-environment nexus given the effect of the earthquakes on all these sectors. Without this collaboration, communicable disease outbreaks will further strain the already overburdened health system and cause further harm to the population.

The Acinetobacter baumannii website (Ab-web): a multidisciplinary knowledge hub, communication platform, and workspace.

Acinetobacter baumannii is a Gram-negative bacterium increasingly implicated in hospital-acquired infections and outbreaks. Effective prevention and control of such infections are commonly challenged by the frequent emergence of multidrug-resistant strains. Here we introduce Ab-web (https://www.acinetobacterbaumannii.no), the first online platform for sharing expertise on A. baumannii. Ab-web is a species-centric knowledge hub, initially with 10 articles organized into two main sections, 'Overview' and 'Topics', and three themes, 'epidemiology', 'antibiotic resistance', and 'virulence'. The 'workspace' section provides a spot for colleagues to collaborate, build, and manage joint projects. Ab-web is a community-driven initiative amenable to constructive feedback and new ideas.

Insights into the genetic contexts of sulfonamide resistance among early clinical isolates of Acinetobacter baumannii.

Since the late 1930s, resistance to sulfonamides has been accumulating across bacterial species including Acinetobacter baumannii, an opportunistic pathogen increasingly implicated the spread of antimicrobial resistance worldwide. Our study aimed to explore events involved in the acquisition of sulfonamide resistance genes, particularly sul2, among the earliest available isolates of A. baumannii. The study utilized the genomic data of 19 strains of A. baumannii isolated before 1985. The whole genomes of 5 clinical isolates obtained from the Culture Collection University of Göteborg (CCUG), Sweden, were sequenced using the Illumina MiSeq system. Acquired resistance genes, insertion sequence elements and plasmids were detected using ResFinder, ISfinder and Plasmidseeker, respectively, while sequence types (STs) were assigned using the PubMLST Pasteur scheme. BLASTn was used to verify the occurrence of sul genes and to map their genetic surroundings. The sul1 and sul2 genes were detected in 4 and 9 isolates, respectively. Interestingly, sul2 appeared thirty years earlier than sul1. The sul2 gene was first located in the genomic island GIsul2 located on a plasmid, hereafter called NCTC7364p. With the emergence of international clone 1, the genetic context of sul2 evolved toward transposon Tn6172, which was also plasmid-mediated. Sulfonamide resistance in A. baumannii was efficiently acquired and transferred vertically, e.g., among the ST52 and ST1 isolates, as well as horizontally among non-related strains by means of a few efficient transposons and plasmids. Timely acquisition of the sul genes has probably contributed to the survival skill of A. baumannii under the high antimicrobial stress of hospital settings.

Politicization of water, humanitarian response, and health in Syria as a contributor to the ongoing cholera outbreak.

In September 2022, the Syrian Ministry of Health declared a cholera outbreak after a surge of acute watery diarrhea cases. Since then, cases have been reported across Syria, particularly in the northwest. This ongoing outbreak reflects a pattern of politicizing water, humanitarian response, and health throughout the country's protracted conflict. Interference with water, sanitation, and hygiene (WASH) infrastructure has been a key component of this politicization, impeding detection, prevention, case management, and control. Droughts and floods have exacerbated the WASH situation, as have the early 2023 Türkiye-Syria earthquakes. The humanitarian response after the earthquakes has also faced politicization, leading to increased risk of surges in cases of cholera and other waterborne diseases. This has all occurred in a conflict where health care has been weaponized, attacks on health care and related infrastructure are the norm, and syndromic surveillance and outbreak response have been influenced and restricted by politics. Cholera outbreaks are entirely preventable; what we see in Syria is cholera reflecting the myriad ways in which the right to health has been brought under fire in the Syrian conflict. The recent earthquakes are additional assaults, which raise urgent concerns that a surge of cholera cases, particularly in northwest Syria, may now become uncontrolled.

Disruption to water supply and waterborne communicable diseases in northeast Syria: a spatiotemporal analysis.

BACKGROUND: In Syria, disruption to water and sanitation systems, together with poor access to vaccination, forced displacement and overcrowding contribute to increases in waterborne diseases (WBDs). The aim of this study is to perform a spatiotemporal analysis to investigate potential associations between interruptions to water, sanitation, and hygiene (WASH) and WBDs in northeast Syria using data collected by the Early Warning Alert and Response Network (EWARN) from Deir-ez-Zor, Raqqa, Hassakeh and parts of Aleppo governorates. METHODS: We reviewed the literature databases of MEDLINE and Google Scholar and the updates of ReliefWeb to obtain information on acute disruptions and attacks against water infrastructure in northeast Syria between January 2015 and June 2021. The EWARN weekly trends of five syndromes representing waterborne diseases were plotted and analysed to identify time trends and the influence of these disruptions. To investigate a potential relationship, the Wilcoxon rank sum test was used to compare districts with and without disruptions. Time series analyses were carried out on major disruptions to analyse their effect on WBD incidence. RESULTS: The literature review found several instances where water infrastructure was attacked or disrupted, suggesting that water has been deliberately targeted by both state and non-state actors in northeast Syria throughout the conflict. Over time, there was an overall upwards trend of other acute diarrhoea (OAD, p < 0.001), but downwards trends for acute jaundice syndrome, suspected typhoid fever and acute bloody diarrhoea. For the major disruption of the Alouk water plant, an interrupted time series analysis did not find a strong correlation between the disruption and changes in disease incidence in the weeks following the incident, but long-term increases in WBD were observed. CONCLUSIONS: While no strong immediate correlation could be established between disruptions to WASH and WBDs in northeast Syria, further research is essential to explore the impact of conflict-associated damage to civil infrastructure including WASH. This is vital though challenging given confounding factors which affect both WASH and WBDs in contexts like northeast Syria. As such, research which includes exploration of mitigation after damage to WASH is essential to improve understanding of impacts on quantity and quality of WASH. More granular research which explores the origin of cases of WBDs and how such communities are affected by challenges to WASH is needed. One step towards research on this, is the implementation of adequate reporting mechanisms for real time tracking of the WASH attacks, damages, direct effects, and likely impact in conjunction with environmental and public health bodies and surveillance systems.

Evidence of Antimicrobial Resistance in Bats and Its Planetary Health Impact for Surveillance of Zoonotic Spillover Events: A Scoping Review.

As a result of the COVID-19 pandemic, as well as other outbreaks, such as SARS and Ebola, bats are recognized as a critical species for mediating zoonotic infectious disease spillover events. While there is a growing concern of increased antimicrobial resistance (AMR) globally during this pandemic, knowledge of AMR circulating between bats and humans is limited. In this paper, we have reviewed the evidence of AMR in bats and discussed the planetary health aspect of AMR to elucidate how this is associated with the emergence, spread, and persistence of AMR at the human-animal interface. The presence of clinically significant resistant bacteria in bats and wildlife has important implications for zoonotic pandemic surveillance, disease transmission, and treatment modalities. We searched MEDLINE through PubMed and Google Scholar to retrieve relevant studies (n = 38) that provided data on resistant bacteria in bats prior to 30 September 2022. There is substantial variability in the results from studies measuring the prevalence of AMR based on geographic location, bat types, and time. We found all major groups of Gram-positive and Gram-negative bacteria in bats, which are resistant to commonly used antibiotics. The most alarming issue is that recent studies have increasingly identified clinically significant multi-drug resistant bacteria such as Methicillin Resistant Staphylococcus aureus (MRSA), ESBL producing, and Colistin resistant Enterobacterales in samples from bats. This evidence of superbugs abundant in both humans and wild mammals, such as bats, could facilitate a greater understanding of which specific pathways of exposure should be targeted. We believe that these data will also facilitate future pandemic preparedness as well as global AMR containment during pandemic events and beyond.

Teleclinical Microbiology: An Innovative Approach to Providing Web-Enabled Diagnostic Laboratory Services in Syria.

OBJECTIVES: Telemedicine can compensate for the lack of health care specialists in response to protracted humanitarian crises. We sought to assess the usability of a teleclinical microbiology (TCM) program to provide diagnostic services in a hard-to-reach region of Syria. METHODS: A semimobile station was equipped with conventional micrograph and macrograph digital imaging systems. An electronic platform (Telemicrobiology in Humanitarian Crises, TmHC) was created to facilitate sharing, interpreting, and storing the results. A pilot study was conducted to identify the bacterial species and antimicrobial susceptibility pattern of 74 urinary clinical isolates. An experience survey was conducted to capture the feedback of 8 participants in the program. RESULTS: The TmHC platform (https://sdh.ngo/tmhc/) enabled systematic transmission of the laboratory records and co-interpretation of the results. The isolates were identified as Escherichia coli (n = 61), Klebsiella pneumoniae (n = 12), and Proteus mirabilis(n = 1). All the isolates were multidrug resistant. The performance of our TCM module was rated 4 (satisfying) and 5 (very satisfying) by 6 and 2 users, respectively. Data security of and cost-effectiveness were the main perceived concerns. CONCLUSIONS: Although we encountered several context-related obstacles, our TCM program managed to reach a highly vulnerable population of 4 million people confined in the northwest region of Syria.

Antimicrobial resistance in the protracted Syrian conflict: halting a war in the war.

The Syrian conflict has damaged key infrastructure and indirectly affected almost all parts of the Middle East and Europe, with no end in sight. Exhausting conditions created by the Syrian crisis and related massive displacement promote the emergence of numerous public health problems that fuel antimicrobial resistance (AMR) development. Here, we explore the current situation of the Syrian displaced population, and AMR inside Syria and among refugees in host countries. We then suggest a roadmap of selected key interventions and strategies to address the threat of AMR in the context of the Syrian crisis. These recommendations are intended to urge health policy-makers in governments and international health organizations to optimize and push for implementing an effective policy taking into consideration the current obstacles.

Weaponizing water as an instrument of war in Syria: Impact on diarrhoeal disease in Idlib and Aleppo governorates, 2011-2019.

OBJECTIVES: Investigate the weaponization of water during the Syrian conflict and the correlation of attacks on water, sanitation, and hygiene (WASH) infrastructure in Idlib and Aleppo governorates with trends in waterborne diseases reported by Early Warning and Response surveillance systems. METHODS: We reviewed literature and databases to obtain information on attacks on WASH in Aleppo and Idlib governorates between 2011 and 2019. We plotted weekly trends in waterborne diseases from two surveillance systems operational in Aleppo and Idlib governorates between 2015 and early 2020. RESULTS: The literature review noted several attacks on water and related infrastructure in both governorates, suggesting that WASH infrastructure was weaponized by state and non-state actors. Most interference with WASH in the Aleppo governorate occurred before 2019 and in the Idlib governorate in the summer of 2020. Other acute diarrhea represented >90% of cases of diarrhea; children under 5 years contributed 50% of cases. There was substantial evidence (p < 0.001) of an overall upward trend in cases of diarrheal disease. CONCLUSIONS: Though no direct correlation can be drawn between the weaponization of WASH and the burden of waterborne infections due to multiple confounders, this research introduces important concepts on attacks on WASH and their potential impacts on waterborne diseases.

CRISPR-based subtyping to track the evolutionary history of a global clone of Acinetobacter baumannii.

Acinetobacter baumannii global clone 1 (GC1) is the second most common clone in the global population of A. baumannii isolates and a key cause of hospital-acquired infections. In this study, comparative analysis of the clustered regularly interspaced short palindromic repeats (CRISPR)-based sequence types (CST) was performed to determine the genetic relatedness and track patterns of descent among 187 GC1 isolates, as a complement to the evolutionary inferences from their multilocus sequence types and genome-wide single nucleotide polymorphism (SNP)-based phylogeny. The CST2 cluster, CST2 and all the CSTs descending from CST2, corresponded to GC1 lineage 1. This cluster included 143 of the 187 isolates showing a prevalent geographical distribution worldwide. A well-demarcated group of 13 CSTs, accounting for 33 of the 187 isolates, corresponded to GC1 lineage 2. All the CSTs of this group were characterized by the absence of spacer Ab-18. Many of the GC1 lineage 2 isolates had an epidemiological link to the Middle East and/or were obtained in military healthcare facilities. GC1 lineage 3 was a novel lineage that has so far been limited to Afghanistan, Pakistan and India. Diversification of A. baumannii GC1 into lineages and clades has probably been related to a dynamic expansion after passing a migration bottleneck to enter the hospital environment. We conclude that CRISPR-based subtyping is a convenient method to trace the evolutionary history of particular bacterial clones, such as A. baumannii GC1.

Guideline for Urine Culture and Biochemical Identification of Bacterial Urinary Pathogens in Low-Resource Settings.

Medical diagnosis in low-resource settings is confronted by the lack of suitable guidelines, protocols and checklists. Online-accessible procedural documents are difficult to find, might be mistranslated or interpreted and usually do not address the needs of developing countries. Urinalysis, one of the most frequently performed diagnostic examinations worldwide, involves a series of tests aiming to detect particular disorders, such as urinary tract infections, kidney disease and diabetes. In this guideline, we present an alternative approach for clinical laboratories with limited resources to identify common bacterial uropathogens. We propose dividing the identification plan into two levels. The implicated pathogen will first be assigned into a bacterial group, basic identification, against which a suitable panel of antimicrobial agents shall be selected for the antimicrobial susceptibility testing (AST). Characterization of the pathogen to the genus or species level, advanced identification, will then be performed to ensure correct reading of the AST results and determine the epidemiology of clinically significant pathogens. Most of the proposed steps in our guideline are tailored to meet the needs of clinical laboratories in low-resource settings. Such guidelines are needed to strengthen the capacity of regional pathology laboratories and to enhance international initiatives on antimicrobial resistance and health equity.

Heavy Metal Toxicity in Armed Conflicts Potentiates AMR in A. baumannii by Selecting for Antibiotic and Heavy Metal Co-resistance Mechanisms.

Acinetobacter baumannii has become increasingly resistant to leading antimicrobial agents since the 1970s. Increased resistance appears linked to armed conflicts, notably since widespread media stories amplified clinical reports in the wake of the American invasion of Iraq in 2003. Antimicrobial resistance is usually assumed to arise through selection pressure exerted by antimicrobial treatment, particularly where treatment is inadequate, as in the case of low dosing, substandard antimicrobial agents, or shortened treatment course. Recently attention has focused on an emerging pathogen, multi-drug resistant A. baumannii (MDRAb). MDRAb gained media attention after being identified in American soldiers returning from Iraq and treated in US military facilities, where it was termed "Iraqibacter." However, MDRAb is strongly associated in the literature with war injuries that are heavily contaminated by both environmental debris and shrapnel from weapons. Both may harbor substantial amounts of toxic heavy metals. Interestingly, heavy metals are known to also select for antimicrobial resistance. In this review we highlight the potential causes of antimicrobial resistance by heavy metals, with a focus on its emergence in A. baumanni in war zones.

Molecular epidemiology and antimicrobial resistance features of Acinetobacter baumannii clinical isolates from Pakistan.

BACKGROUND: Acinetobacter baumannii is a Gram-negative opportunistic pathogen with a notorious reputation of being resistant to antimicrobial agents. The capability of A. baumannii to persist and disseminate between healthcare settings has raised a major concern worldwide. METHODS: Our study investigated the antibiotic resistance features and molecular epidemiology of 52 clinical isolates of A. baumannii collected in Pakistan between 2013 and 2015. Antimicrobial susceptibility patterns were determined by the agar disc diffusion method. Comparative sequence analyses of the ampC and blaOXA-51-like alleles were used to assign the isolates into clusters. The whole genomes of 25 representative isolates were sequenced using the MiSeq Desktop Sequencer. Free online applications were used to determine the phylogeny of genomic sequences, retrieve the multilocus sequence types (ST), and detect acquired antimicrobial resistance genes. RESULTS: Overall, the isolates were grouped into 7 clusters and 3 sporadic isolates. The largest cluster, Ab-Pak-cluster-1 (blaOXA-66 and ISAba1-ampC-19) included 24 isolates, belonged to ST2 and International clone (IC) II, and was distributed between two geographical far-off cities, Lahore and Peshawar. Ab-Pak-clusters-2 (blaOXA-66, ISAba1-ampC-2), and -3 (blaOXA-66, ISAba1-ampC-20) and the individual isolate Ab-Pak-Lah-01 (ISAba1-blaOXA-66, ISAba1-ampC-2) were also assigned to ST2 and IC II. On the other hand, Ab-Pak-clusters-4 (blaOXA-69, ampC-1), -5 (blaOXA-69, ISAba1-ampC-78), and -6A (blaOXA-371, ISAba1-ampC-3) belonged to ST1, while Ab-Pak-cluster-6B (blaOXA-371, ISAba1-ampC-8) belonged to ST1106, with both ST1 and ST1106 being members of IC I. Five isolates belonged to Ab-Pak-cluster-7 (blaOXA-65, ampC-43). This cluster corresponded to ST158, showed a well-delineated position on the genomic phylogenetic tree, and was equipped with several antimicrobial resistance genes including blaOXA-23 and blaGES-11. CONCLUSIONS: Our study detected the occurrence of 7 clusters of A. baumannii in Pakistan. Altogether, 6/7 of the clusters and 45/52 (86.5%) of the isolates belonged to IC I (n = 9) or II (n = 36), making Pakistan no exception to the global domination of these two clones. The onset of ST158 in Pakistan marked a geographical dispersal of this clone beyond the Middle East and brought up the need for a detailed characterization.

The challenges of tuberculosis control in protracted conflict: The case of Syria.

OBJECTIVES: Syria's protracted conflict has resulted in ideal conditions for the transmission of tuberculosis (TB) and the cultivation of drug-resistant strains. This paper compares TB control in Syria before and after the conflict using available data, examines the barriers posed by protracted conflict and those specific to Syria, and discusses what measures can be taken to address the control of TB in Syria. RESULTS: Forced mass displacement and systematic violations of humanitarian law have resulted in overcrowding and the destruction of key infrastructure, leading to an increased risk of both drug-sensitive and resistant TB, while restricting the ability to diagnose, trace contacts, treat, and follow-up. Pre-conflict, TB in Syria was officially reported at 22 per 100 000 population; the official figure for 2017 of 19 per 100 000 is likely a vast underestimate given the challenges and barriers to case detection. Limited diagnostics also affect the diagnosis of multidrug- and rifampicin-resistant TB, reported as comprising 8.8% of new diagnoses in 2017. CONCLUSIONS: The control of TB in Syria requires a multipronged, tailored, and pragmatic approach to improve timely diagnosis, increase detection, stop transmission, and mitigate the risk of drug resistance. Solutions must also consider vulnerable populations such as imprisoned and besieged communities where the risk of drug resistance is particularly high, and must recognize the limitations of national programming. Strengthening capacity to control TB in Syria with particular attention to these factors will positively impact other parallel conditions; this is key as attention turns to post-conflict reconstruction.

Analysis of colony phase variation switch in Acinetobacter baumannii clinical isolates.

Reversible switching between opaque and translucent colony formation is a novel feature of Acinetobacter baumannii that has been associated with variations in the cell morphology, surface motility, biofilm formation, antibiotic resistance and virulence. Here, we assessed a number of phenotypic alterations related to colony switching in A. baumannii clinical isolates belonging to different multi-locus sequence types. Our findings demonstrated that these phenotypic alterations were mostly strain-specific. In general, the translucent subpopulations of A. baumannii produced more dense biofilms, were more piliated, and released larger amounts of outer membrane vesicles (OMVs). In addition, the translucent subpopulations caused reduced fertility of Caenorhabditis elegans. When assessed for effects on the immune response in RAW 264.7 macrophages, the OMVs isolated from opaque subpopulations of A. baumannii appeared to be more immunogenic than the OMVs from the translucent form. However, also the OMVs from the translucent subpopulations had the potential to evoke an immune response. Therefore, we suggest that OMVs may be considered for development of new immunotherapeutic treatments against A. baumannii infections.