Black Phosphorus Nanoflakes: An Emerging Nanomaterial for Clinical Wound Management and Biomedical Applications Luke S. Smith, Hanif Haidari, Anteneh Amsalu, Gordon S. Howarth, Saffron J. Bryant, et al. International Journal of Molecular Sciences, 2024 Black phosphorus (BP), a two-dimensional material, has gathered significant attention over the last decade, primarily due to its unique physiochemical properties and potential role in various biomedical applications. This review provides an in-depth overview of the synthesis, nanomaterial properties, interactions, and biomedical uses of BP, with a particular focus on wound management. The structure, synthesis methods, and stability of BP are discussed, highlighting the high degree of nanomaterial biocompatibility and cytotoxicity. The antimicrobial properties of BP, including mechanisms of action and preclinical studies to date, are examined, emphasizing the effectiveness of BP against various clinical pathogens relevant to wound management. Additionally, the versatility of BP in biomedical implementations is highlighted through utilization in drug delivery, imaging, and photothermal therapy, with a focus on scalability and reproducibility with outlined future perspectives. Despite identified challenges for translation in clinical uses, BP nanomaterial has significant potential as a versatile platform in biomedical applications, especially in wound management.
Multidrug-resistant Stenotrophomonas maltophilia in residential aged care facilities: An emerging threat Sylvia A. Sapula, Bradley J. Hart, Naomi L. Siderius, Anteneh Amsalu, Jack M. Blaikie, et al. Microbiologyopen, 2024 Stenotrophomonas maltophilia is a multidrug‐resistant (MDR), Gram‐negative bacterium intrinsically resistant to beta‐lactams, including last‐resort carbapenems. As an opportunistic pathogen, it can cause serious healthcare‐related infections. This study assesses the prevalence, resistance profiles, and genetic diversity of S. maltophilia isolated from residential aged care facilities (RACFs). RACFs are known for their overuse and often inappropriate use of antibiotics, creating a strong selective environment that favors the development of bacterial resistance. The study was conducted on 73 S. maltophilia isolates recovered from wastewater and facility swab samples obtained from three RACFs and a retirement village. Phenotypic and genotypic assessments of the isolates revealed high carbapenem resistance, exemplifying their intrinsic beta‐lactam resistance. Alarmingly, 49.3% (36/73) of the isolates were non‐wild type for colistin, with minimum inhibitory concentration values of > 4 mg/L, and 11.0% (8/73) were resistant to trimethoprim‐sulfamethoxazole. No resistance mechanisms were detected for either antimicrobial. Genotypic assessment of known lineages revealed isolates clustering with Sm17 and Sm18, lineages not previously reported in Australia, suggesting the potential ongoing spread of MDR S. maltophilia. Lastly, although only a few isolates were biocide tolerant (2.7%, 2/73), their ability to grow in high concentrations (64 mg/L) of triclosan is concerning, as it may be selecting for their survival and continued dissemination.
Resistome Analysis of Klebsiella pneumoniae Complex from Residential Aged Care Facilities Demonstrates Intra-facility Clonal Spread of Multidrug-Resistant Isolates Jack M. Blaikie, Sylvia A. Sapula, Naomi L. Siderius, Bradley J. Hart, Anteneh Amsalu, et al. Microorganisms, 2024 Antimicrobial-resistant Klebsiella pneumoniae is one of the predominant pathogens in healthcare settings. However, the prevalence and resistome of this organism within residential aged care facilities (RACFs), which are potential hotspots for antimicrobial resistance, remain unexplored. Here, we provide a phenotypic and molecular characterization of antimicrobial-resistant K. pneumoniae isolated from RACFs. K. pneumoniae was isolated from urine, faecal and wastewater samples and facility swabs. The antimicrobial susceptibility profiles of all the isolates were determined and the genomic basis for resistance was explored with whole-genome sequencing on a subset of isolates. A total of 147 K. pneumoniae were isolated, displaying resistance against multiple antimicrobials. Genotypic analysis revealed the presence of beta-lactamases and the ciprofloxacin-resistance determinant QnrB4 but failed to confirm the basis for the observed cephalosporin resistance. Clonal spread of the multidrug-resistant, widely disseminated sequence types 323 and 661 was observed. This study was the first to examine the resistome of K. pneumoniae isolates from RACFs and demonstrated a complexity between genotypic and phenotypic antimicrobial resistance. The intra-facility dissemination and persistence of multidrug-resistant clones is concerning, given that residents are particularly vulnerable to antimicrobial resistant infections, and it highlights the need for continued surveillance and interventions to reduce the risk of outbreaks.
The scope of antimicrobial resistance in residential aged care facilities determined through analysis of Escherichia coli and the total wastewater resistome Sylvia A. Sapula, Anteneh Amsalu, Jon J. Whittall, Bradley J. Hart, Naomi L. Siderius, et al. Microbiology Spectrum, 2023 High and often inappropriate antibiotic use has been documented for residential aged care facilities (RACFs). As a result, RACFs represent selective environments favoring the development of antimicrobial resistance (AMR). However, surveillance of the prevalence and scope of AMR in RACFs is limited. Here, wastewater-based epidemiology encompassing culture-based methods in combination with whole genome sequencing and metagenomics allowed for the in-depth analysis of the prevalence of antimicrobial-resistant Escherichia coli in two RACFs and one retirement facility. Wastewater was collected at five different time points over 18 months. From these, E. coli were isolated and assessed for phenotypic and genotypic resistance. The antimicrobial resistome of each wastewater sample was also determined. A comparison of facilities revealed a higher prevalence of AMR and multidrug-resistant E. coli observed in one RACF. The international high-risk E. coli clone, ST131, carrying CTX-M-like extended-spectrum beta-lactamases was exclusively isolated from this facility. A high proportion of these isolates were classified as belonging to phylogroups B2 and D, associated with virulent extra-intestinal E. coli infections. The resistome of this facility also revealed a higher prevalence of mobile resistance genes such as sul1 and sul2 , conferring sulfamethoxazole resistance, the plasmid-mediated quinolone-resistance gene qnrS , and qacEdelta1 that confers biocide resistance. High fluoroquinolone resistance rates were observed in all three sample sites despite measures in place limiting the use of this class of antibiotics. The findings of this study illustrate that RACFs are highly selective environments that require measures to limit AMR development, potentially through antimicrobial stewardship. IMPORTANCE Antimicrobial resistance (AMR) is a global threat that imposes a heavy burden on our health and economy. Residential aged care facilities (RACFs), where frequent inappropriate antibiotic use creates a selective environment that promotes the development of bacterial resistance, significantly contribute to this problem. We used wastewater-based epidemiology to provide a holistic whole-facility assessment and comparison of antimicrobial resistance in two RACFs and a retirement village. Resistant Escherichia coli , a common and oftentimes problematic pathogen within RACFs, was isolated from the wastewater, and the phenotypic and genotypic AMR was determined for all isolates. We observed a high prevalence of an international high-risk clone, carrying an extended-spectrum beta-lactamase in one facility. Analysis of the entire resistome also revealed a greater number of mobile resistance genes in this facility. Finally, both facilities displayed high fluoroquinolone resistance rates—a worrying trend seen globally despite measures in place aimed at limiting their use.
Seroprevalence and associated factors of hepatitis B and C virus among pulmonary tuberculosis patients attending health facilities in Gondar Town, Northwest Ethiopia Birhanu Getie, Getnet Ayalew, Anteneh Amsalu, Getachew Ferede, Gizachew Yismaw, et al. Infection and Drug Resistance, 2021 Background Hepatitis B virus (HBV) and hepatitis C virus (HCV) are hepatotropic viruses whose primary replication occurs in the liver. Despite the significant clinical importance of early screening of hepatitis B and C virus infection in decreasing the hepatotoxicity effect of anti-tuberculosis drugs, screening of hepatitis B and C virus among tuberculosis (TB) patients before treatment has not been practiced in Ethiopia. Thus, this study was conducted to determine the seroprevalence and associated factors of HBV and HCV infections among pulmonary TB (PTB) patients attending health facilities in Gondar, Northwest Ethiopia. Methods A cross-sectional study was conducted among 145 bacteriologically confirmed PTB patients from January 1 to May 30, 2019. After obtaining a signed informed consent from each participant, data on socio-demographic, clinical, and associated factors were collected using a structured pre-tested questionnaire. Besides, a blood sample was collected to determine HBsAg and HCV antibodies by enzyme linked immune sorbent assay (ELISA). The data were entered and analyzed using SPSS version 21. A Fisher’s exact test was used to see the relationship between dependent and independent variables, and a p-value ≤0.05 was considered as statistically significant. Results Out of the 145 PTB patients screened, 5 (3.4%) patients tested positive for HBsAg, yet none of them were found to be positive for anti-HCV. Besides, the proportion of HIV-positive was 12 (8.3%). History of hospital admission (P= 0.005), tattooing (P= 0.009) and dental extraction (P=0.003) were significantly associated with HBsAg. Conclusion Although anti-HCV antibodies were not detected, the prevalence of HBV was relatively high in tuberculosis patients. This study highlights the need for the introduction of routine screening of viral hepatitis markers for all TB patients before anti-TB treatment for better management of patients. Likewise, further clinical and epidemiological studies are needed.
Worldwide distribution and environmental origin of the Adelaide imipenemase (AIM-1), a potent carbapenemase in Pseudomonas aeruginosa Anteneh Amsalu, Sylvia A. Sapula, Jonathan J. Whittall, Bradley J. Hart, Jan M. Bell, et al. Microbial Genomics, 2021 Carbapenems are potent broad-spectrum β-lactam antibiotics reserved for the treatment of serious infections caused by multidrug-resistant bacteria such as Pseudomonas aeruginosa . The surge in P. aeruginosa resistant to carbapenems is an urgent threat, as very few treatment options remain. Resistance to carbapenems is predominantly due to the presence of carbapenemase enzymes. The assessment of 147 P . aeruginosa isolates revealed that 32 isolates were carbapenem non-wild-type. These isolates were screened for carbapenem resistance genes using PCR. One isolate from wastewater contained the Adelaide imipenemase gene (bla AIM-1) and was compared phenotypically with a highly carbapenem-resistant clinical isolate containing the bla AIM-1 gene. A further investigation of wastewater samples from various local healthcare and non-healthcare sources as well as river water, using probe-based qPCR, revealed the presence of the bla AIM-1 gene in all the samples analysed. The widespread occurrence of bla AIM-1 throughout Adelaide hinted at the possibility of more generally extensive spread of this gene than originally thought. A blast search revealed the presence of the bla AIM-1 gene in Asia, North America and Europe. To elucidate the identity of the organism(s) carrying the bla AIM-1 gene, shotgun metagenomic sequencing was conducted on three wastewater samples from different locations. Comparison of these nucleotide sequences with a whole-genome sequence of a P. aeruginosa isolate revealed that, unlike the genetic environment and arrangement in P. aeruginosa , the bla AIM-1 gene was not carried as part of any mobile genetic elements. A phylogenetic tree constructed with the deduced amino acid sequences of AIM-1 suggested that the potential origin of the bla AIM-1 gene in P. aeruginosa might be the non-pathogenic environmental organism, Pseudoxanthomonas mexicana .
High burden of nosocomial infections caused by multi-drug resistant pathogens in pediatric patients at Hawassa University comprehensive specialized hospital Ethiopian Medical Journal, 2019
Immune protection of hepatitis B vaccine among children living in Gondar, northwest Ethiopia Ethiopian Medical Journal, 2019
Investigations on antimicrobial resistance: Contributions of a clinical research network Ethiopian Medical Journal, 2019
Characterisation of the wound microbiome and antimicrobial resistance profiles in clinical isolates from epidermolysis bullosa patients A Amsalu, H Haidari, B Mirco, V Rudolph-Stringer, S Walter, A Antipov, ... Orphanet Journal of Rare Diseases 21 (1), 151 , 2026 2026
Safety and Efficacy Validation of Stimuli Responsive Silver Hydrogel for Rapid Elimination of Bacterial Infection in Murine and Porcine Wounds A Antipov, T Kennewell, A Abdo, A Amsalu, H Haidari, Z Kopecki WOUND REPAIR AND REGENERATION 33 (6), 21-18 , 2025 2025
Risk factors for antimicrobial resistance in paediatric burn infections: Insights from a retrospective cohort study A Amsalu, A Alvaro, S Huang, A May, A Antipov, L Quinn, B Carney, ... Burns 51 (6), 107584 , 2025 2025
Black phosphorus nanoflakes: an emerging nanomaterial for clinical wound management and biomedical applications LS Smith, H Haidari, A Amsalu, GS Howarth, SJ Bryant, S Walia, ... International Journal of Molecular Sciences 25 (23), 12824 , 2024 2024 Citations: 11
An on-demand antibacterial hydrogel for precise and rapid elimination of bacterial infection in a murine partial thickness scald burn wound H Haidari, A Amsalu, K Vasilev, AJ Cowin, Z Kopecki Applied Materials Today 38, 102237 , 2024 2024 Citations: 18
Multidrug‐resistant Stenotrophomonas maltophilia in residential aged care facilities: An emerging threat SA Sapula, BJ Hart, NL Siderius, A Amsalu, JM Blaikie, H Venter Microbiologyopen 13 (3), e1409 , 2024 2024 Citations: 10
Resistome Analysis of Klebsiella pneumoniae Complex from Residential Aged Care Facilities Demonstrates Intra-facility Clonal Spread of Multidrug-Resistant … JM Blaikie, SA Sapula, NL Siderius, BJ Hart, A Amsalu, LEX Leong, ... Microorganisms 12 (4), 751 , 2024 2024 Citations: 7
The scope of antimicrobial resistance in residential aged care facilities determined through analysis of Escherichia coli and the total wastewater resistome SA Sapula, A Amsalu, JJ Whittall, BJ Hart, NL Siderius, L Nguyen, ... Microbiology spectrum 11 (6), e00731-23 , 2023 2023 Citations: 12
Worldwide distribution and environmental origin of the Adelaide imipenemase (AIM-1), a potent carbapenemase in Pseudomonas aeruginosa A Amsalu, SA Sapula, JJ Whittall, BJ Hart, JM Bell, J Turnidge, H Venter Microbial genomics 7 (12), 000715 , 2021 2021 Citations: 21
Seroprevalence and associated factors of hepatitis B and C virus among pulmonary tuberculosis patients attending health facilities in Gondar Town, Northwest Ethiopia B Getie, G Ayalew, A Amsalu, G Ferede, G Yismaw, B Tessema Infection and Drug Resistance, 3599-3608 , 2021 2021 Citations: 12
Efflux Pump-Driven Antibiotic and Biocide Cross-Resistance in Pseudomonas aeruginosa Isolated from Different Ecological Niches: A Case Study in the … A Amsalu, SA Sapula, M De Barros Lopes, BJ Hart, AH Nguyen, B Drigo, ... Microorganisms 8 (11), 1647 , 2020 2020 Citations: 114
Extended-spectrum β-lactamases-producing enterobacteria and antimicrobial resistance pattern among HIV/AIDS patients in the university of gondar specialized hospital, Ethiopia D Endalamaw, A Amsalu, S Biset, F Mekonnen, M Balew, S Eshetie Recent Adv Biol Med 6 (1), 11909 , 2020 2020 Citations: 4
Prevalence of Methicillin‐Resistant Staphylococcus aureus and Associated Risk Factors among Patients with Wound Infection at Referral Hospital, Northeast Ethiopia Y Tsige, S Tadesse, T G/Eyesus, MM Tefera, A Amsalu, MA Menberu, ... Journal of pathogens 2020 (1), 3168325 , 2020 2020 Citations: 50
Magnitude of hepatitis B and C virus infections and associated factors among patients scheduled for surgery at Hawassa University comprehensive specialized Hospital, Hawassa … M Taye, D Daka, A Amsalu, S Hussen BMC Research Notes 12 (1), 412 , 2019 2019 Citations: 27
Investigations on antimicrobial resistance: contributions of a clinical research network A Aseffa, E Abate, B Seyoum, T Kassa, T Abebe, A Amsalu, A Bitew, ... Ethiop Med J 1, 3-7 , 2019 2019 Citations: 2
Immune protection of hepatitis B vaccine among children living in Gondar, northwest Ethiopia G Ayalew, A Assefa, A Amsalu, M Geta, A Mihret, A Aseffa, R Howe, ... Ethiop Med J , 2019 2019 Citations: 11
The role of neutrophil to lymphocyte count ratio in the differential diagnosis of pulmonary tuberculosis and bacterial community-acquired pneumonia: a cross-sectional study at … M Berhane, M Melku, A Amsalu, B Enawgaw, Z Getaneh, F Asrie Clinical laboratory 65 (4) , 2019 2019 Citations: 84
High burden of Nosocomial infections caused by multi-drug Re-sistant pathogens in pediatric patients at Hawassa university comprehensive specialized hospital T Alemayehu, E Tadesse, S Ayalew, B Nigusse, B Yeshitila, A Amsalu, ... Ethiopian Medical Journal 58, 45-55 , 2019 2019 Citations: 25
Prevalence and associated factors of treatment failure among HIV/AIDS patients on HAART attending University of Gondar Referral Hospital Northwest Ethiopia G Ayele, B Tessema, A Amsalu, G Ferede, G Yismaw BMC immunology 19 (1), 37 , 2018 2018 Citations: 86
Bacterial profile, antibiotic resistance pattern and associated factors among cancer patients at University of Gondar Hospital, Northwest Ethiopia A Fentie, Y Wondimeneh, A Balcha, A Amsalu, BT Adankie Infection and drug resistance, 2169-2178 , 2018 2018 Citations: 56
MOST CITED SCHOLAR PUBLICATIONS
Seroprevalence of HIV, HBV, HCV and syphilis infections among blood donors at Gondar University Teaching Hospital, Northwest Ethiopia: declining trends over a period of five years B Tessema, G Yismaw, A Kassu, A Amsalu, A Mulu, F Emmrich, U Sack BMC Infectious diseases 10 (1), 111 , 2010 2010 Citations: 386
Seroprevalence and associated risk factors of hepatitis B virus among pregnant women in southern Ethiopia: a hospital-based cross-sectional study Y Metaferia, W Dessie, I Ali, A Amsalu Epidemiology and health 38, e2016027 , 2016 2016 Citations: 122
Efflux Pump-Driven Antibiotic and Biocide Cross-Resistance in Pseudomonas aeruginosa Isolated from Different Ecological Niches: A Case Study in the … A Amsalu, SA Sapula, M De Barros Lopes, BJ Hart, AH Nguyen, B Drigo, ... Microorganisms 8 (11), 1647 , 2020 2020 Citations: 114
Prevalence of uropathogen and their antibiotic resistance pattern among diabetic patients D Nigussie, A Amsalu Turkish journal of urology 43 (1), 85 , 2017 2017 Citations: 104
Bacterial pathogens associated with external ocular infections alongside eminent proportion of multidrug resistant isolates at the University of Gondar Hospital, northwest Ethiopia E Getahun, B Gelaw, A Assefa, Y Assefa, A Amsalu BMC ophthalmology 17 (1), 151 , 2017 2017 Citations: 100
Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis S Eshetie, F Tarekegn, F Moges, A Amsalu, W Birhan, K Huruy BMC infectious diseases 16 (1), 689 , 2016 2016 Citations: 96
Prevalence, Infectivity, and Associated Risk Factors of Hepatitis B Virus among Pregnant Women in Yirgalem Hospital, Ethiopia: Implication of Screening to Control Mother‐to … A Amsalu, G Ferede, S Eshetie, A Tadewos, D Assegu Journal of pregnancy 2018 (1), 8435910 , 2018 2018 Citations: 87
Prevalence and associated factors of treatment failure among HIV/AIDS patients on HAART attending University of Gondar Referral Hospital Northwest Ethiopia G Ayele, B Tessema, A Amsalu, G Ferede, G Yismaw BMC immunology 19 (1), 37 , 2018 2018 Citations: 86
The role of neutrophil to lymphocyte count ratio in the differential diagnosis of pulmonary tuberculosis and bacterial community-acquired pneumonia: a cross-sectional study at … M Berhane, M Melku, A Amsalu, B Enawgaw, Z Getaneh, F Asrie Clinical laboratory 65 (4) , 2019 2019 Citations: 84
Typhoid fever: clinical presentation and associated factors in febrile patients visiting Shashemene Referral Hospital, southern Ethiopia L Habte, E Tadesse, G Ferede, A Amsalu BMC research notes 11 (1), 605 , 2018 2018 Citations: 80
Impact of HIV status on treatment outcome of tuberculosis patients registered at Arsi Negele Health Center, Southern Ethiopia: a six year retrospective study G Gebremariam, G Asmamaw, M Hussen, MZ Hailemariam, D Asegu, ... PloS one 11 (4), e0153239 , 2016 2016 Citations: 68
The exposure rate to hepatitis B and C viruses among medical waste handlers in three government hospitals, southern Ethiopia A Amsalu, M Worku, E Tadesse, T Shimelis Epidemiology and health 38, e2016001 , 2016 2016 Citations: 58
Bacterial profile, antibiotic resistance pattern and associated factors among cancer patients at University of Gondar Hospital, Northwest Ethiopia A Fentie, Y Wondimeneh, A Balcha, A Amsalu, BT Adankie Infection and drug resistance, 2169-2178 , 2018 2018 Citations: 56
Pediatric urinary tract infection as a cause of outpatient clinic visits in southern Ethiopia: a cross sectional study E Mitiku, A Amsalu, BT Tadesse Ethiopian journal of health sciences 28 (2), 187 , 2018 2018 Citations: 56
High seroprevalence of syphilis infection among pregnant women in Yiregalem hospital southern Ethiopia A Amsalu, G Ferede, D Assegu BMC infectious diseases 18 (1), 109 , 2018 2018 Citations: 51
Prevalence of Methicillin‐Resistant Staphylococcus aureus and Associated Risk Factors among Patients with Wound Infection at Referral Hospital, Northeast Ethiopia Y Tsige, S Tadesse, T G/Eyesus, MM Tefera, A Amsalu, MA Menberu, ... Journal of pathogens 2020 (1), 3168325 , 2020 2020 Citations: 50
Potential bacterial pathogens of external ocular infections and their antibiotic susceptibility pattern at Hawassa University Teaching and Referral Hospital, Southern Ethiopia A Amsalu, T Abebe, A Mihret, D Delelegne, E Tadesse Afr J Microbiol Res 9 (14), 1012-1019 , 2015 2015 Citations: 40
Coinfections with hepatitis B and C virus and syphilis among HIV-infected clients in Southern Ethiopia: a cross-sectional study T Shimelis, Y Tassachew, A Tadewos, MW Hordofa, A Amsalu, ... HIV/AIDS-Research and Palliative Care, 203-210 , 2017 2017 Citations: 36
Antimicrobial resistance pattern of bacterial isolates from different clinical specimens in Southern Ethiopia: A three year retrospective study A Amsalu, Z Geto, D Asegu, S Eshetie African Journal of Bacteriology Research 9 (1), 1-8 , 2017 2017 Citations: 36
Risk factors of metabolic syndrome among hypertensive patients at Hawassa University Comprehensive Specialized Hospital, Southern Ethiopia A Tadewos, T Egeno, A Amsalu BMC cardiovascular disorders 17 (1), 218 , 2017 2017 Citations: 33
