Displaying publications 41 - 60 of 267 in total

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  1. Fulltext Whole genome sequencing and genomic characteristics analysis of carbapenem-resistant Acinetobacter baumannii clinical isolates in two hospitals in China
    Tian C, Di L, Dong S, Tian X, Huang D, Zhao Y, et al.
    Infect Genet Evol, 2024 Sep;123:105642.
    PMID: 39013496 DOI: 10.1016/j.meegid.2024.105642
    Nosocomial outbreaks caused by carbapenem-resistant Acinetobacter baumannii (CRAB) strains are rapidly emerging worldwide and are cause for concern. Herein, we aimed to describe the genomic characteristics of CRAB strains isolated from two hospitals in China in 2023. The A. baumannii isolates were mainly collected from the ICU and isolated from the sputum (71.43%, 15/21), followed by urine (14.29%, 3/21). Twenty-one A. baumannii strains possessed a multidrug-resistant (MDR) profile, and whole-genome sequencing showed that they all carried blaOXA-23. Based on the Pasteur multilocus sequence typing (MLST) scheme, all strains were typed into a sequence type 2 (ST2). Based on the Oxford MLST scheme, six strains belonged to ST540, three of which were ST208, and four strains were assigned to ST784. Kaptive showed most of the strains (38.10%, 8/21) contained KL93. As for the lipoolygosaccharide (OC locus) type, OCL1c and OCL1d were identified, accounting for 33.33% (7/21) and 66.67% (14/21), respectively. Based on the BacWGSTdb server, we found that the strains belonging to ST540 and ST784 were all collected from China. However, the ST938 strains were isolated from Malaysia and Thailand. Comparative genomics analysis showed that the AB10 strain had a closed relationship with SXAB10-SXAB13 strains, suggesting the transmission happened in these two hospitals and other hospital in China. In addition, the 4300STDY7045869 strain, which was collected from Thailand, possessed near genetic relationship with our isolates in this study, suggesting the possible spread among various countries. Additionally, 3-237 single nucleotide polymorphisms were observed among these strains. In conclusion, this study conducted a genome-based study for A. baumannii strains collected from two hospitals in China and revealed their epidemiological and molecular features. Clone spreading occurred in these two hospitals. Hence, there is an urgent need for increased surveillance in hospitals and other clinical settings to prevent and control CRAB spreading.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/genetics
  2. Phage therapeutic delivery methods and clinical trials for combating clinically relevant pathogens
    Selim HMRM, Gomaa FAM, Alshahrani MY, Morgan RN, Aboshanab KM
    Ther Deliv, 2025 Mar;16(3):247-269.
    PMID: 39545771 DOI: 10.1080/20415990.2024.2426824
    The ongoing global health crisis caused by multidrug-resistant (MDR) bacteria necessitates quick interventions to introduce new management strategies for MDR-associated infections and antimicrobial agents' resistance. Phage therapy emerges as an antibiotic substitute for its high specificity, efficacy, and safety profiles in treating MDR-associated infections. Various in vitro and in vivo studies denoted their eminent bactericidal and anti-biofilm potential. This review addresses the latest developments in phage therapy regarding their attack strategies, formulations, and administration routes. It additionally discusses and elaborates on the status of phage therapy undergoing clinical trials, and the challenges encountered in their usage, and explores prospects in phage therapy research and application.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial*
  3. Fulltext Green Synthesis and Characterization of Silver Nanoparticles Using Zingiber officinale Extracts to Investigate Their Antibacterial Potential
    Ramzan M, Abusalah MAHA, Ahmed N, Yean CY, Zeshan B
    Int J Nanomedicine, 2024;19:13319-13338.
    PMID: 39679248 DOI: 10.2147/IJN.S475656
    BACKGROUND AND PURPOSE: Antimicrobial resistance (AMR) has emerged as a significant global concern. To combat this growing threat, various strategies have been employed, including the use of plant extracts and the biosynthesis of nanoparticles (NPs). The current study was designed to evaluate the phytochemical analysis of ginger (Zingiber officinale) extracts, characterize the silver nanoparticles (AgNPs) and to see their antibacterial potentials against multi-drug resistant (MDR) bacterial strains.

    METHODS: The extracts were prepared and initially assessed for their phytochemical composition and antibacterial activity. Then, AgNPs were synthesized from these extracts at room temperature, and various analytical techniques, including UV-visible spectroscopy, X-ray diffraction (XRD), ATIR-FTIR, zeta sizer, scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDXA), were used to characterize the NPs. After confirmation of prepared NPs, they were subjected to their antibacterial activity.

    RESULTS: HPLC analysis demonstrated the presence of eight phytoconstituents in organic ginger extracts. The absorption spectra of the silver suspension exhibited surface plasmon resonance peaks with maxima between 420 and 448 nm. Functional groups like C-H, N-H, OH, C-O-C, C=O, and C-O were identified in both the organic and aqueous extracts of Z. officinale, playing a key role in the formation of AgNPs, as characterized by ATR-FTIR analysis. Both ginger organic and aqueous extract synthesized AgNPs crystalline structure was shown in XRD analysis and the particle size distribution showed average diameter of 200.5 nm of AgNPs from aqueous extracts. Scanning Electron Microscopy displayed spherical structure and EDA results showed the percentage of elements in synthesized AgNPs using plant extracts. Most promising antibacterial activity was obtained against Escherichia coli ie 20.83±0.53 for 100 µg/mL.

    CONCLUSION: The results of the current study showed that AgNPs synthesized from different ginger extracts have promising antibacterial properties and can be potential candidates for alternative treatment options for bacterial infections.

    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/drug effects
  4. Investigation of suspected Candidozyma auris outbreaks in Malaysia using integrated genomic, clinical, and antifungal susceptibility analyses
    Tan XT, Cheng JT, Tuang WX, Lee HG, Khamis SN, Sharizam NFM, et al.
    Med Mycol, 2026 Oct 02;64(10).
    PMID: 42847927 DOI: 10.1093/mmy/myag109
    Candidozyma auris (formerly Candida auris) is an emerging multidrug-resistant fungus with limited genomic epidemiological data from Malaysia. This study investigated the genomic epidemiology, clinical characteristics and antifungal susceptibility of C. auris outbreak isolates using an integrated whole-genome sequencing (WGS) approach. Eleven clinical C. auris isolates from five healthcare facilities across three Malaysian states were analysed alongside clinical and epidemiological data. Antifungal susceptibility testing was performed for azoles, echinocandins, amphotericin B, flucytosine, and manogepix. Among 11 patients, seven had candidemia and four were colonized. Median age was 48 years, with diabetes mellitus, chronic kidney disease, and hypertension as the most common comorbidities. All candidemia patients had urinary and central venous catheters; 71% required mechanical ventilation, 43% had haemodialysis and recent surgery, respectively. Recent antibiotic exposure was common, whereas none had prior antifungal therapy. All isolates belonged to Clade I but separated into distinct genomic clusters, supporting healthcare-associated transmission within clusters and simultaneous circulation of multiple genomic groups. All Johor-associated isolates were fluconazole resistant and carried ERG11 K143R and CDR1 V704L substitutions. An ERG5 variant was detected in non-Johor isolates with amphotericin B minimum inhibitory concentrations (MICs) ≥ 1 µg/ml. The MICs for other antifungals remained low across isolates. Echinocandin therapy was initiated in 27% of patients, with one survivor. Our C. auris showed genomic diversity, distinct healthcare-associated clustering, and variable antifungal susceptibility. Integrating WGS with clinical and susceptibility data enhanced outbreak investigation of C. auris.
    Matched MeSH terms: Drug Resistance, Multiple, Fungal/genetics
  5. Fulltext Charting the Voyages of Acinetobacter baumannii in Southeast Asia: Mapping the Regional Genomic Landscape
    Lean SS, Palittapongarnpim P, Clarke SC, Yeo CC
    Microbiologyopen, 2026 Dec;15(6).
    PMID: 42961112 DOI: 10.1002/mbo3.70446
    Acinetobacter baumannii is a critical-priority nosocomial pathogen, yet its genomic epidemiology in Southeast Asia remains fragmented. We analysed publicly available genomes to define the regional A. baumannii population structure, resistome, mobile genetic elements, and phage defence repertoire. Following quality filtering, 853 genomes from Southeast Asia which were retrieved from PubMLST and NCBI, were subjected to multilocus sequence typing, pangenome-based phylogenetic analysis, antimicrobial resistance gene screening, plasmid and resistance island characterisation, and defence-system profiling. The dataset spanned 1996-2024 and included genomes from seven Southeast Asian countries, with Thailand contributing the largest number. The Global Clone 2 (GC2) lineage dominated the regional A. baumannii population and formed major country-associated clades, although non-dominant GCs and non-GC isolates persisted throughout the sampling period. blaOXA-23, blaADC-73, and tetB were the most prevalent acquired resistance determinants, while the gyrA-S81L and parC-S84L mutations, which are associated with fluoroquinolone resistance, were widespread across the Southeast Asian isolates. AbaR-type resistance islands were confined to GC1, whereas AbGRI-type islands predominated in GC2, especially AbGRI1-5. R3-type plasmids were the most widely distributed plasmid family overall, although RP-type plasmids predominated in Indonesia. Phage defence systems were lineage-associated, with GC2 enriched for SspBCDE and Gao-type systems and other lineages showing distinct defence combinations. Southeast Asian A. baumannii is therefore characterised by dominant GC2 circulation, broad dissemination of key resistance determinants, diverse mobile genetic elements, and heterogeneous phage defence repertoires. These findings provide a regional genomic baseline for surveillance and highlight the need for broader, geographically representative sampling across Southeast Asia.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/genetics
  6. Fulltext Ecology and epidemiology of multidrug resistance Salmonella in fruit Bats and shared water sources in Bangladesh
    Uddin MH, Dutta P, Islam M, Rahman MK, Islam S, Karim MR, et al.
    PLoS One, 2026;21(10):e0361701.
    PMID: 42961893 DOI: 10.1371/journal.pone.0361701
    Antimicrobial resistance (AMR) is a growing global threat to both animal and human health, underscoring the importance of AMR surveillance across all sectors of the One Health triad, including wildlife. Fruit bats in Bangladesh frequently inhabit areas in close proximity to human settlements and livestock facilities, creating ecological conditions that facilitate the co-occurrence of AMR bacteria through direct contact or shared contaminated environments. A cross-sectional study was conducted to determine the prevalence of Salmonella spp. isolation and the proportion of antimicrobial-resistant isolates among confirmed positives, characterize resistance patterns across multiple antimicrobial classes, and identify associated risk factors in fruit bat populations and environmental water sources in Bangladesh. We collected 369 fecal samples from the roosts of two bat species, Pteropus medius and Rousettus leschenaultii, along with 22 water samples from water bodies utilized by humans, livestock, and bats. Salmonella spp. isolates were identified using selective agar culture, followed by biochemical testing and confirmation via polymerase chain reaction (PCR). Confirmed isolates underwent antimicrobial susceptibility testing via the Kirby-Bauer disc diffusion method against 12 antimicrobials. The prevalence of AMR Salmonella spp. was 7.9% (95% CI: 5.3-11.1%) in bat's roost fecal samples and 31.8% (95% CI: 13.9-54.9%) in environmental water samples. Bat-derived isolates showed high resistance to tetracycline (93%), nalidixic acid (86%), sulfamethoxazole-trimethoprim (80%), and azithromycin (76%). Among the identified AMR isolates, 28 (96.5%) met the criteria for multidrug resistance (MDR), defined as resistance to three or more antimicrobial classes. Water-derived isolates also demonstrated high resistance, particularly to tetracycline (86%), amoxicillin-clavulanic acid (75%), azithromycin (73%), ceftriaxone (72%), and ciprofloxacin (71%). Multivariable logistic regression analysis revealed that the odds ratio (OR) of detection of MDR Salmonella spp. in fruit bats was 5.1 times higher during the summer season compared to winter. These findings highlight the evidence of MDR Salmonella spp. in fruit bats and shared environmental water sources in Bangladesh. The co-occurrence of resistant isolates across wildlife and environmental samples highlights the need for integrated AMR surveillance encompassing wildlife reservoirs and shared ecological interfaces. Strengthened antimicrobial stewardship, improved wastewater management, and coordinated One Health surveillance strategies are essential to mitigate the risk of zoonotic spillover and reduce further ecological overlap of MDR bacteria at the wildlife-livestock-human interface in Bangladesh and the broader South Asian region.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial*
  7. Comparison of Clinical Isolates of Aeromonas from Singapore and Malaysia with Regard to Molecular Identification, Virulence, and Antimicrobial Profiles
    Khor WC, Puah SM, Koh TH, Tan JAMA, Puthucheary SD, Chua KH
    Microb Drug Resist, 2018 May;24(4):469-478.
    PMID: 29461928 DOI: 10.1089/mdr.2017.0083
    OBJECTIVE: The objective of this study was to examine the species distribution, genetic relatedness, virulence gene profiles, antimicrobial sensitivities, and resistance gene distribution of clinical Aeromonas strains from Singapore and Malaysia.

    METHODS: A total of 210 Aeromonas clinical isolates were investigated: 116 from Singapore General Hospital and 94 archived clinical isolates from University of Malaya Medical Center, Malaysia. The isolates were genetically identified based on the gcat gene screening and the partial sequences of the rpoD housekeeping gene. Genetic relatedness, distribution of 15 virulence genes and 4 beta-lactamase resistance genes, and susceptibility patterns to 11 antimicrobial agents were compared.

    RESULTS: Of the 210 Aeromonas isolates, A. dhakensis-94 (45%) was the dominant species in Singapore and Malaysia. Species composition was similar and enterobacterial repetitive intergenic consensus-PCR did not show genetic relatedness between strains from the two countries. Of the 15 virulence genes, A. dhakensis and A. hydrophila harbored the most compared with other species. Different combinations of 9 virulence genes (exu, fla, lip, eno, alt, dam, hlyA, aexU, and ascV) were present in A. dhakensis, A. hydrophila, and A. veronii from both the countries. Distribution of virulence genes was species and anatomic site related. Majority (>80%) of the strains were susceptible to all antimicrobial agents tested, except amoxicillin and cephalothin. A. dhakensis strains from Malaysia significantly harbored the cphA gene compared with A. dhakensis from Singapore. Multidrug resistance was mostly detected in strains from peritoneal fluids of dialysis patients.

    CONCLUSION: This study revealed A. dhakensis as the dominant species isolated in both geographic regions, and that it carried a high number of virulence genes. It also highlights the geographic-related differences of virulence gene distribution and antimicrobial resistance profiles of clinical Aeromonas strains from Singapore and Malaysia.

    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/drug effects; Drug Resistance, Multiple, Bacterial/genetics
  8. Molecular Characterization of Extended-Spectrum Beta Lactamase- and Carbapenemase-Producing Pseudomonas aeruginosa Strains from a Malaysian Tertiary Hospital
    Phoon HYP, Hussin H, Hussain BM, Thong KL
    Microb Drug Resist, 2018 Oct;24(8):1108-1116.
    PMID: 29437541 DOI: 10.1089/mdr.2017.0258
    Pseudomonas aeruginosa infections account for high morbidity and mortality rates worldwide. Increasing resistance toward β-lactams, especially carbapenems, poses a serious therapeutic challenge. However, the multilocus sequence typing (MLST) of extended-spectrum beta lactamase (ESBL)- and carbapenemase-producing clinical P. aeruginosa has not been reported in Malaysia. This study aimed to determine the antibiotic susceptibility profiles, resistance genes, pulsotypes, and sequence types (STs) of clinical P. aeruginosa from a Malaysian tertiary hospital. These characteristics were analyzed by disk diffusion, minimum inhibitory concentration, polymerase chain reaction, pulsed-field gel electrophoresis (PFGE), and MLST for 199 nonreplicate clinical strains. The susceptibility of the strains toward the carbapenems and piperacillin-tazobactam was the lowest (≤90%), while ≥90% of the strains remained susceptible to all other classes of antimicrobial agents tested. The multidrug-resistant strains displayed high level resistance to cephalosporins (48 to ≥256 mg/L) and carbapenems (4-32 mg/L). Eleven strains harbored class 1 integrons containing blaGES-13, blaVIM-2, blaVIM-6, blaOXA-10, aacA(6')-Ib, aacA(6')-II, aadA6, and gcuD gene cassettes. Extra-integron genes, blaGES-20, blaIMP-4, blaVIM-2, and blaVIM-11, were also found. Overall, the maximum likelihood tree showed concordance in the clustering of strains having the same STs and PFGE clusters. ST708 was the predominant antibiotic-susceptible clone detected from the neonatal intensive care unit. The STs 235, 809, and 1076 clonal clusters consisted of multidrug resistant strains. ST235 is a recognized international high-risk clone. This is the first report of blaGES-13 and blaGES-20 ESBL-encoding gene variants and novel STs (STs 2329, 2335, 2337, 2338, 2340, and 2341) of P. aeruginosa in Malaysia.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/drug effects; Drug Resistance, Multiple, Bacterial/genetics
  9. Appropriateness of empirical antibiotics: risk factors of adult patients with sepsis in the ICU
    Al-Sunaidar KA, Prof Abd Aziz N, Prof Hassan Y
    Int J Clin Pharm, 2020 Apr;42(2):527-538.
    PMID: 32144611 DOI: 10.1007/s11096-020-01005-4
    Background The appropriateness of antibiotics is the basis for improving the survival of patients with sepsis. Objective This study aimed to determine the appropriateness of empirical antibiotics, reasons for non-appropriate empirical antibiotics, risk factors of mortality, length of stay in intensive care unit (ICU-LOS) and Acute Physiology And Chronic Health Evaluation II (APACHE II) score predictors in adult patients with sepsis. Setting An adult ICU of a tertiary hospital in  Malaysia. Methods A retrospective cohort study was conducted amongst patients with sepsis. Data were retrieved from the patients' files and computer system. Each case was reviewed for the appropriateness of empirical antibiotics based on ICU local guidelines, bacterial sensitivity, dose, frequency, creatinine clearance and time of administration of empirical antibiotics. Multivariable logistic and Cox regression modelling were performed to compute the adjusted association of receiving appropriate or inappropriate empirical antibiotics with ICU mortality. Multivariable linear regression modelling was performed using ICU-LOS and APACHE II scores. Main outcome measures were ICU mortality, severity score (APACHE II scores) and ICU-LOS. Results The total mortality rate amongst the 228 adult ICU patients was 84.6%. Males showed a higher mortality rate (119 [52.2%]) than females (74 [32.5%]). Inappropriate empirical antibiotics were significantly associated with mortality and ICU-LOS (P 
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/drug effects*; Drug Resistance, Multiple, Bacterial/physiology
  10. Genotypic and phenotypic differentiation of Salmonella enterica serovar Paratyphi B in Malaysia
    Thong KL, Ang CP
    Southeast Asian J Trop Med Public Health, 2011 Sep;42(5):1178-89.
    PMID: 22299444
    Abstract. Salmonella enterica serovar Paratyphi B is known to cause either paratyphoid fever or gastroenteritis. Differentiation of Salmonella ser. Paratyphi B into biotype Java (d-tartrate fermenting, dT+) and biotype Paratyphi B (d-tartrate non-fermenting, dT) is important for Salmonella epidemiology. This study applied a PCR approach to differentiate the two biotypes to augment the conventional biochemical method and to determine the antibiograms and genomic diversity of Malaysian S. Paratyphi B. Among 100 strains tested (clinical, 86; non-humans, 14), only two clinical strains were confirmed as biotype Paratyphi B as indicated by both lead acetate test and PCR. Antibiotic resistance rates were as follows: streptomycin 18%, sulphonamides 13%, ampicillin 10%, chloramphenicol 4%, tetracycline 3%, cefotaxime 2%, cefpodoxime 2%, ceftazidime 2%, gentamicin 1% and trimethoprim 1%. None showed resistance towards amoxicillin-clavulanic acid, ceftiofur, ciprofloxacin, nalidixic acid and trimethoprim-sulphamethoxazole. Seven strains showed multidrug resistance towards 3 or more classes of antimicrobial agents. REP-PCR and PFGE generated 32 and 76 different profiles, respectively. PFGE (D = 0.99) was more discriminative than REP-PCR (D = 0.93) and antimicrobial susceptibility test (D = 0.48) in subtyping the strains. Strains isolated 18 years apart (1982 - 2008) from different localities in Malaysia were clonally related as demonstrated by REP-PCR and PFGE, indicating that these strains were stable and widely distributed. In some clusters, strains isolated from different sources (clinical, food and animal) were grouped together. Thus, biotype Java was the most common biotype of Salmonella ser. Paratyphi B in Malaysia. The PCR approach is highly recommended due to its simplicity, specificity and ease of operation. The level of antimicrobial resistance among Salmonella ser. Paratyphi B remained relatively low in Malaysia but the emergence of resistance to cephalosporins is a cause for concern.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial/drug effects; Drug Resistance, Multiple, Bacterial/genetics*
  11. Interpretation and application of virological testing including resistance in chronic hepatitis B
    Locarnini S
    Med J Malaysia, 2005 Jul;60 Suppl B:41-51.
    PMID: 16108173
    Matched MeSH terms: Drug Resistance, Multiple, Viral/genetics; Drug Resistance, Multiple, Viral/immunology*
  12. Fulltext Prevalence and Antimicrobial Susceptibility of Vibrio parahaemolyticus Isolated from Short Mackerels (Rastrelliger brachysoma) in Malaysia
    Tan CW, Malcolm TTH, Kuan CH, Thung TY, Chang WS, Loo YY, et al.
    Front Microbiol, 2017;8:1087.
    PMID: 28659901 DOI: 10.3389/fmicb.2017.01087
    Numerous prevalence studies and outbreaks of Vibrio parahaemolyticus infection have been extensively reported in shellfish and crustaceans. Information on the quantitative detection of V. parahaemolyticus in finfish species is limited. In this study, short mackerels (Rastrelliger brachysoma) obtained from different retail marketplaces were monitored with the presence of total and pathogenic strains of V. parahaemolyticus. Out of 130 short mackerel samples, 116 (89.2%) were detected with the presence of total V. parahaemolyticus and microbial loads of total V. parahaemolyticus ranging from <3 to >10(5) MPN/g. Prevalence of total V. parahaemolyticus was found highest in wet markets (95.2%) followed by minimarkets (89.1%) and hypermarkets (83.3%). Pathogenic V. parahaemolyticus strains (tdh+ and/or trh+) were detected in 16.2% (21 of 130) of short mackerel samples. The density of tdh+ V. parahaemolyticus strains were examined ranging from 3.6 to >10(5) MPN/g and microbial loads of V. parahaemolyticus strains positive for both tdh and trh were found ranging from 300 to 740 MPN/g. On the other hand, antibiotic susceptibility profiles of V. parahaemolyticus strains isolated from short mackerels were determined through disc diffusion method in this study. Assessment of antimicrobial susceptibility profile of V. parahaemolyticus revealed majority of the isolates were highly susceptible to ampicillin sulbactam, meropenem, ceftazidime, and imipenem, but resistant to penicillin G and ampicillin. Two isolates (2.99%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.41 which shown resistance to 7 antibiotics. Results of the present study demonstrated that the occurrence of pathogenic V. parahaemolyticus strains in short mackerels and multidrug resistance of V. parahaemolyticus isolates could be a potential public health concerns to the consumer. Furthermore, prevalence data attained from the current study can be further used to develop a microbial risk assessment model to estimate health risks associated with the consumption of short mackerels contaminated with pathogenic V. parahaemolyticus.
    Matched MeSH terms: Drug Resistance, Multiple
  13. Fulltext Small, Enigmatic Plasmids of the Nosocomial Pathogen, Acinetobacter baumannii: Good, Bad, Who Knows?
    Lean SS, Yeo CC
    Front Microbiol, 2017;8:1547.
    PMID: 28861061 DOI: 10.3389/fmicb.2017.01547
    Acinetobacter baumannii is a Gram-negative nosocomial pathogen that has become a serious healthcare concern within a span of two decades due to its ability to rapidly acquire resistance to all classes of antimicrobial compounds. One of the key features of the A. baumannii genome is an open pan genome with a plethora of plasmids, transposons, integrons, and genomic islands, all of which play important roles in the evolution and success of this clinical pathogen, particularly in the acquisition of multidrug resistance determinants. An interesting genetic feature seen in majority of A. baumannii genomes analyzed is the presence of small plasmids that usually ranged from 2 to 10 kb in size, some of which harbor antibiotic resistance genes and homologs of plasmid mobilization genes. These plasmids are often overlooked when compared to their larger, conjugative counterparts that harbor multiple antibiotic resistance genes and transposable elements. In this mini-review, we will examine our current knowledge of these small A. baumannii plasmids and look into their genetic diversity and phylogenetic relationships. Some of these plasmids, such as the Rep-3 superfamily group and the pRAY-type, which has no recognizable replicase genes, are quite widespread among diverse A. baumannii clinical isolates worldwide, hinting at their usefulness to the lifestyle of this pathogen. Other small plasmids especially those from the Rep-1 superfamily are truly enigmatic, encoding only hypothetical proteins of unknown function, leading to the question of whether these small plasmids are "good" or "bad" to their host A. baumannii.
    Matched MeSH terms: Drug Resistance, Multiple
  14. Rational use of intravenous polymyxin B and colistin: A review
    Zakuan ZD, Suresh K
    Med J Malaysia, 2018 10;73(5):351-359.
    PMID: 30350826 MyJurnal
    Polymyxin B and colistin (polymyxin E) were introduced in clinical practice to treat Gram-negative infections in 1950s but their parenteral use waned in 1970s due to toxicity concerns. Resurgence of polymyxins use in Malaysia began approximately in 2009 due to a lack of treatment options for MDR Gram negative superbugs such as Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa. However, limited experience and a lack of widespread availability of up-to-date dosing guidelines could potentially result in incorrect use of these last resort antibiotics by managing doctors. The recent report of polymyxin resistant strains is also a cause of concern. Herein, we discuss the importance of preserving the efficacy of polymyxins in hospitals, the similarities and differences between polymyxin B and colistin, issues pertaining to current use of polymxyins and strategies to improve polymyxins' prescription. Polymyxins should only be used to treat significant infections, in optimum doses and if possible, in combination with other antibiotics.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial
  15. The Travelling Particles: Investigating microplastics as possible transport vectors for multidrug resistant E. coli in the Weser estuary (Germany)
    Song J, Jongmans-Hochschulz E, Mauder N, Imirzalioglu C, Wichels A, Gerdts G
    Sci Total Environ, 2020 Jun 10;720:137603.
    PMID: 32143053 DOI: 10.1016/j.scitotenv.2020.137603
    The prevalence of multidrug-resistant Gram-negative bacteria in aquatic environments has been a long withstanding health concern, namely extended-spectrum beta-lactamase (ESBL) producing Escherichia coli. Given increasing reports on microplastic (MP) pollution in these environments, it has become crucial to better understand the role of MP particles as transport vectors for such multidrug-resistant bacteria. In this study, an incubation experiment was designed where particles of both synthetic and natural material (HDPE, tyre wear, and wood) were sequentially incubated at multiple sites along a salinity gradient from the Lower Weser estuary (Germany) to the offshore island Helgoland (German Bight, North Sea). Following each incubation period, particle biofilms and water samples were assessed for ESBL-producing E. coli, first by the enrichment and detection of E. coli using Fluorocult® LMX Broth followed by cultivation on CHROMAgar™ ESBL media to select for ESBL-producers. Results showed that general E. coli populations were present on the surfaces of wood particles across all sites but none were found to produce ESBLs. Additionally, neither HDPE nor tyre wear particles were found to harbour any E. coli. Conversely, ESBL-producing E. coli were present in surrounding waters from all sites, 64% of which conferred resistances against up to 3 other antibiotic groups, additional to the beta-lactam resistances intrinsic to ESBL-producers. This study provides a first look into the potential of MP to harbour and transport multidrug-resistant E. coli across different environments and the approach serves as an important precursor to further studies on other potentially harmful MP-colonizing species.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial
  16. Fulltext Prevalence and antibiotic resistance patterns of Vibrio parahaemolyticus isolated from different types of seafood in Selangor, Malaysia
    Tan CW, Rukayadi Y, Hasan H, Thung TY, Lee E, Rollon WD, et al.
    Saudi J Biol Sci, 2020 Jun;27(6):1602-1608.
    PMID: 32489301 DOI: 10.1016/j.sjbs.2020.01.002
    Vibrio parahaemolyticus is a foodborne bacterial pathogen that may cause gastroenteritis in humans through the consumption of seafood contaminated with this microorganism. The emergence of antimicrobial and multidrug-resistant bacteria is another serious public health threat worldwide. In this study, the prevalence and antibiotic susceptibility test of V. parahaemolyticus in blood clams, shrimps, surf clams, and squids were determined. The overall prevalence of V. parahaemolyticus in seafood was 85.71% (120/140), consisting of 91.43% (32/35) in blood clam, 88.57% (31/35) in shrimps, 82.86% (29/35) in surf clams, and 80% (28/35) in squids. The majority of V. parahaemolyticus isolates from the seafood samples were found to be susceptible to most antibiotics except ampicillin, cefazolin, and penicillin. The MAR indices of V. parahaemolyticus isolates ranged from 0.04 to 0.71 and about 90.83% of isolates were found resistant to more than one antibiotic. The high prevalence of V. parahaemolyticus in seafood and multidrug-resistant isolates detected in this study could pose a potential risk to human health and hence appropriate control methods should be in place to minimize the potential contamination and prevent the emergence of antibiotic resistance.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial
  17. Community-acquired pneumonia: aetiology, antibiotic resistance and prospects of phage therapy
    Sheam MM, Syed SB, Nain Z, Tang SS, Paul DK, Ahmed KR, et al.
    J Chemother, 2020 Dec;32(8):395-410.
    PMID: 32820711 DOI: 10.1080/1120009X.2020.1807231
    Bacteria are the most common aetiological agents of community-acquired pneumonia (CAP) and use a variety of mechanisms to evade the host immune system. With the emerging antibiotic resistance, CAP-causing bacteria have now become resistant to most antibiotics. Consequently, significant morbimortality is attributed to CAP despite their varying rates depending on the clinical setting in which the patients being treated. Therefore, there is a pressing need for a safe and effective alternative or supplement to conventional antibiotics. Bacteriophages could be a ray of hope as they are specific in killing their host bacteria. Several bacteriophages had been identified that can efficiently parasitize bacteria related to CAP infection and have shown a promising protective effect. Thus, bacteriophages have shown immense possibilities against CAP inflicted by multidrug-resistant bacteria. This review provides an overview of common antibiotic-resistant CAP bacteria with a comprehensive summarization of the promising bacteriophage candidates for prospective phage therapy.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial
  18. Fulltext Green Synthesis and Characterization of Silver Nanoparticles Using Spondias mombin Extract and Their Antimicrobial Activity against Biofilm-Producing Bacteria
    Samuggam S, Chinni SV, Mutusamy P, Gopinath SCB, Anbu P, Venugopal V, et al.
    Molecules, 2021 May 03;26(9).
    PMID: 34063685 DOI: 10.3390/molecules26092681
    Multidrug resistant bacteria create a challenging situation for society to treat infections. Multidrug resistance (MDR) is the reason for biofilm bacteria to cause chronic infection. Plant-based nanoparticles could be an alternative solution as potential drug candidates against these MDR bacteria, as many plants are well known for their antimicrobial activity against pathogenic microorganisms. Spondias mombin is a traditional plant which has already been used for medicinal purposes as every part of this plant has been proven to have its own medicinal values. In this research, the S. mombin extract was used to synthesise AgNPs. The synthesized AgNPs were characterized and further tested for their antibacterial, reactive oxygen species and cytotoxicity properties. The characterization results showed the synthesized AgNPs to be between 8 to 50 nm with -11.52 of zeta potential value. The existence of the silver element in the AgNPs was confirmed with the peaks obtained in the EDX spectrometry. Significant antibacterial activity was observed against selected biofilm-forming pathogenic bacteria. The cytotoxicity study with A. salina revealed the LC50 of synthesized AgNPs was at 0.81 mg/mL. Based on the ROS quantification, it was suggested that the ROS production, due to the interaction of AgNP with different bacterial cells, causes structural changes of the cell. This proves that the synthesized AgNPs could be an effective drug against multidrug resistant bacteria.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial
  19. Fulltext Facing the challenges of multidrug-resistant Acinetobacter baumannii: progress and prospects in the vaccine development
    Mat Rahim N, Lee H, Strych U, AbuBakar S
    Hum Vaccin Immunother, 2021 10 03;17(10):3784-3794.
    PMID: 34106809 DOI: 10.1080/21645515.2021.1927412
    In 2017, the World Health Organization (WHO) named A. baumannii as one of the three antibiotic-resistant bacterial species on its list of global priority pathogens in dire need of novel and effective treatment. With only polymyxin and tigecycline antibiotics left as last-resort treatments, the need for novel alternative approaches to the control of this bacterium becomes imperative. Vaccines against numerous bacteria have had impressive records in reducing the burden of the respective diseases and addressing antimicrobial resistance; as in the case of Haemophilus influenzae type b . A similar approach could be appropriate for A. baumannii. Toward this end, several potentially protective antigens against A. baumannii were identified and evaluated as vaccine antigen candidates. A licensed vaccine for the bacteria, however, is still not in sight. Here we explore and discuss challenges in vaccine development against A. baumannii and the promising approaches for improving the vaccine development process.
    Matched MeSH terms: Drug Resistance, Multiple, Bacterial
  20. Fulltext Antimicrobial susceptibility of clinical isolates of Pseudomonas aeruginosa from a Malaysian Hospital
    Pathmanathan SG, Samat NA, Mohamed R
    Malays J Med Sci, 2009 Apr;16(2):27-32.
    PMID: 22589655 MyJurnal
    Ongoing surveillance of Pseudomonas aeruginosa resistance against antimicrobial agents is fundamental to monitor trends in susceptibility patterns and to appropriately guide clinicians in choosing empirical or directed therapy. The in vitro activity level of eight antimicrobial drugs was assessed against 97 clinical isolates of P. aeruginosa collected consecutively for three months in 2007 from a Malaysian hospital. Antimicrobial susceptibility was determined using the E-test method in addition to the hospital's routine diagnostic testing by the disk diffusion method. Respiratory and wound swab isolates were the most frequently encountered isolates. The E-test and disk diffusion methods showed high concordance in determining the in vitro activity of the antimicrobial agents against the E isolates. Piperacillin-tazobactam was the most active antimicrobial agent with 91.8% susceptibility, followed by the aminoglycosides (amikacin, 86.6% and gentamicin, 84.5%), the quinolone (ciprofloxacin, 83.5%) and the beta-lactams (cefepime, 80.4%, ceftazidime, 80.4%, imipenem, 79.4% and meropenem, 77.3%). Incidence of multidrug resistance was 19.6% (19 out of 97 isolates). Periodic antibiotic resistance surveillance is fundamental to monitor changes in susceptibility patterns in a hospital setting.

    Study site: Hospital Kuala Lumpur
    Matched MeSH terms: Drug Resistance, Multiple
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