Prevalence of extended-spectrum β-lactamases, AmpC, and carbapenemases in Proteus mirabilis clinical isolates

Clonal Dissemination of NDM-Producing Proteus mirabilis in a Teaching Hospital in Sousse, Tunisia

Proteus mirabilis (P. mirabilis) is an opportunistic pathogen involved in urinary tract infections as well as various nosocomial infections. Emerging resistances to beta-lactams in this species complicates potential treatment since it is intrinsically resistant to colistin. Eleven isolates of carbapenem-non-susceptible P. mirabilis were identified in Sousse Hospital, Tunisia, from January 2018 to December 2022. MICs were determined and isolates were sequenced to determine their resistomes, sequence types, virulence factors, and their clonal relationships. Susceptibility testing showed that all isolates were resistant to carbapenems, aminoglycosides, fluoroquinolones, chloramphenicol, and the trimethoprim/sulfamethoxazole combination. They remained susceptible to the aztreonam/avibactam combination. All isolates produced NDM-1 carbapenemase and ArmA 16S rRNA methylase. In addition, one isolate co-produced the blaVEB-6 gene. All isolates belonged to ST135, and phylogenetic analysis revealed that they were closely related. This study described the first outbreak of NDM-1-producing P. mirabilis in Tunisia.

Research in etiology of Floppy Kid Syndrome

Floppy Kid Syndrome (FKS) is a common and serious disease in goats, with incidence rates ranging from 10 to 50% and mortality rates between 20 and 60%. This study aimed to investigate the etiology of FKS through blood biochemical analysis and metagenomic sequencing. Blood biochemical analysis revealed metabolic disorders in FKS-affected goats, including acidosis and hypoglycemia. Metagenomic analysis showed marked gastric and gut dysbacteriosis, characterized by an increase in pathogenic bacteria such as Escherichia coli and Staphylococcus aureus, alongside a significant reduction in probiotic like Lactobacillus amylovorus. Furthermore, species diversity and richness were notably lower in FKS-affected goats compared to healthy goats. Based on these findings, we infer that FKS is a multifactorial disease caused by gastric and gut dysbacteriosis. The immaturity of the digestive system in newborn goats, combined with environmental stressors (such as sudden changes in weather), leads to gastric and gut dysbacteriosis, with a significant reduction in probiotic and an overgrowth of pathogenic bacteria. The dysbacteriosis, along with the inability to properly digest excessive milk intake, contributes to the accumulation of undigested milk in the digestive tract, creating an environment conducive to pathogenic bacteria growth. The fermentation of milk and the production of excessive lactic acid by pathogenic bacteria are absorbed into the bloodstream, causing acidosis and hypoglycemia. These metabolic disorders, in conjunction with the dysbacteriosis and systemic dysfunction, lead to the onset of FKS. These results underscore the critical role of gastric and gut dysbacteriosis in the pathogenesis of FKS, highlighting the need for targeted preventive and therapeutic strategies.

Impact of COVID-19 pandemic on antimicrobial resistance of Proteus mirabilis in a Brazilian hospital

This study analyzes the resistance and virulence profiles of Proteus mirabilis isolates obtained from patients admitted to the University Hospital of Londrina, Paraná, between 2019 and 2022. We evaluated the antimicrobial resistance phenotypes, genes associated with resistance, biofilm formation through a phenotypic assay, and the presence of specific virulence genes. When comparing the "pre-pandemic" (2019) and "pandemic" (2020-2022) periods, we observed an increase in resistance rates to all tested antimicrobials. Multidrug-resistant (MDR) pathogens producing extended-spectrum β-lactamase (ESBL) phenotypes were isolated in both periods, but their occurrence was significantly higher during the pandemic. We also observed an increase in the frequency of nearly all studied resistance genes. The virulence profiles remained largely unchanged. Analysis of patients' clinical and demographic data revealed that those hospitalized during the pandemic were older, required longer hospital stays, and had a higher usage of invasive devices. These findings suggest that the recent COVID-19 pandemic has impacted the antimicrobial resistance of P. mirabilis, a bacterium of significant clinical interest associated with urinary tract infections (UTIs) and healthcare-associated infections (HAIs).

Evolution of β-Lactam Antibiotic Resistance in Proteus Species: From Extended-Spectrum and Plasmid-Mediated AmpC β-Lactamases to Carbapenemases

The management of infectious diseases has proven to be a daunting task for clinicians worldwide, and the rapid development of antibiotic resistance among Gram-negative bacteria is making it even more challenging. The first-line therapy is empirical, and it most often comprises β-lactam antibiotics. Among Gram-negative bacteria, Proteus mirabilis, an important community and hospital pathogen associated primarily with urinary tract and wound infection, holds a special place. This review's aim was to collate and examine recent studies investigating β-lactam resistance phenotypes and mechanisms of Proteus species and the global significance of its β-lactam resistance evolution. Moreover, the genetic background of resistance traits and the role of mobile genetic elements in the dissemination of resistance genes were evaluated. P. mirabilis as the dominant pathogen develops resistance to expanded-spectrum cephalosporins (ESC) by producing extended-spectrum β-lactamases (ESBL) and plasmid-mediated AmpC β-lactamases (p-AmpC). β-lactamase-mediated resistance to carbapenems in Enterobacterales, including Proteus spp., is mostly due to expression of carbapenemases of class A (KPC); class B (metallo-β-lactamases or MBLs of IMP, VIM, or NDM series); or class D or carbapenem-hydrolyzing oxacillinases (CHDL). Previously, a dominant ESBL type in P. mirabilis was TEM-52; yet, lately, it has been replaced by CTX-M variants, particularly CTX-M-14. ESC resistance can also be mediated by p-AmpC, with CMY-16 as the dominant variant. Carbapenem resistance in Proteus spp. is a challenge due to its intrinsic resistance to colistin and tigecyclin. The first carbapenemases reported belonged to class B, most frequently VIM-1 and NDM-5. In Europe, predominantly France and Belgium, a clonal lineage positive for OXA-23 CHDL spreads rapidly undetected, due to its low-level resistance to carbapenems. The amazing capacity of Proteus spp. to accumulate a plethora of various resistance traits is leading to multidrug or extensively drug-resistant phenotypes.

Prevalence and molecular characterization of ESBL-producing Enterobacteriaceae in Egypt: a systematic review and meta-analysis of hospital and community-acquired infections

BACKGROUND

ESBL-producing Enterobacteriaceae (ESBL-PE) represent a significant global health threat. In response to this growing concern and the lack of a surveillance system for ESBL-PE infections in Egypt, we conducted this meta-analysis. In this study, we aimed to quantify the prevalence of ESBL-PE based on the source of infection and characterize their molecular dissemination. Additionally, we sought to uncover temporal trends to assess the spread of ESBL-PE over time.

METHODS

A comprehensive literature search was conducted in PubMed, Scopus, Google Scholar, Web of Science, and the Egyptian Knowledge Bank to identify studies that: (1) report the prevalence of ESBL-PE in Egypt; (2) use valid detection methods; (3) involve clinical specimens; and (4) were published between 2010 and 2024. The quality of the included studies was evaluated using the "Joanna Briggs Institute Critical Appraisal Checklist". Meta-analysis was performed using the R meta package, reporting pooled prevalence with 95% confidence intervals (CI) via a random effects model.

RESULTS

This meta-analysis included 34 studies with 4,528 isolates, spanning 2007 to 2023. The overall prevalence of ESBL-PE in Egypt was 60% (95% CI: 54-65). The leave-one-out meta-analysis demonstrated the absence of influential outliers and Egger's test indicated no evidence of publication bias (P = 0.25). The prevalence of ESBL-PE was 62% (95% CI: 55-68) in nosocomial infections and 65% (95% CI: 52-75) in community-acquired infections, with no statistically significant difference (P = 0.68). The prevalence of ESBL producers in E. coli (64%) and K. pneumoniae (63%) is higher than in Proteus mirabilis (46%) (P = 0.06). Temporal analysis showed a stable ESBL prevalence over time. Moreover, in phenotypically confirmed ESBL-producing, E. coli harboring blaCTX-M was most prevalent (73%), followed by blaTEM (60%) and blaSHV (22%), with significant differences (P < 0.01). Subsequent analysis identified blaCTX-M-15 as the predominant variant of the blaCTX-M gene.

CONCLUSIONS

The prevalence of ESBL-PE in Egypt is alarmingly high at 60%. The observed high rates in both hospital and community-acquired infections underscore the need for public health strategies targeting both settings. One limitation of this study is the high heterogeneity, which partly attributed to regional and institutional variations in antibiotic use and stewardship practices.

Is It Time to Start Worrying? A Comprehensive Report on the Three-Year Prevalence of ESBL-Producing Bacteria and Their Trends in Antibiotic Resistance from the Largest University Hospital in Slovakia

BACKGROUND/OBJECTIVES

Over the past few decades, extended-spectrum β-lactamase (ESBL)-producing bacteria have become a great concern in healthcare systems worldwide, imposing large burdens by increasing antimicrobial resistance and patient morbidity. Given the high mortality rates and emergence of multidrug-resistant (MDR) strains, monitoring ESBL prevalence and resistance patterns is crucial. This study aimed to evaluate ESBL-producing Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae over three years, focusing on phenotypic distribution and resistance profiles.

METHODS

A total of 1599 ESBL-producing bacterial samples were collected and analysed. A panel of 20 antibiotics was tested to determine resistance traits. Data were recorded on phenotypical distribution, isolation types, changes in antibiotic resistance, and the relation of such changes to antibiotic consumption (defined daily dose) from clinical isolates.

RESULTS

Phenotypical analysis revealed the minimal presence of the Cefotaximase from Munich (CTX-M) phenotype in E. coli and K. pneumoniae, creating a distinct epidemiological profile compared to global patterns. Shifts in isolation trends, particularly in P. mirabilis, suggest an expected increase in associated-mortality-rate in the coming years. While resistance trends were not statistically significant, MDR and extensively drug-resistant (XDR) strains were identified across all three bacteria. Only meropenem showed consistent 100% efficacy against E. coli, with other antibiotics displaying only partial effectiveness.

CONCLUSIONS

These findings highlight the need for ongoing surveillance of ESBL-producing bacteria and underscore challenges in managing antibiotic resistance due to limited efficacy of last-resort treatments. The unique phenotypical distribution observed could impact local resistance management strategies in hospital settings in the coming years.

Emergence of extensive drug resistance and high prevalence of multidrug resistance among clinical Proteus mirabilis isolates in Egypt

BACKGROUND

Proteus mirabilis is an opportunistic pathogen that has been held responsible for numerous nosocomial and community-acquired infections which are difficult to be controlled because of its diverse antimicrobial resistance mechanisms.

METHODS

Antimicrobial susceptibility patterns of P. mirabilis isolates collected from different clinical sources in Mansoura University Hospitals, Egypt was determined. Moreover, the underlying resistance mechanisms and genetic relatedness between isolates were investigated.

RESULTS

Antimicrobial susceptibility testing indicated elevated levels of resistance to different classes of antimicrobials among the tested P. mirabilis clinical isolates (n = 66). ERIC-PCR showed great diversity among the tested isolates. Six isolates (9.1%) were XDR while all the remaining isolates were MDR. ESBLs and AmpCs were detected in 57.6% and 21.2% of the isolates, respectively, where blaTEM, blaSHV, blaCTX-M, blaCIT-M and blaAmpC were detected. Carbapenemases and MBLs were detected in 10.6 and 9.1% of the isolates, respectively, where blaOXA-48 and blaNDM-1 genes were detected. Quinolone resistant isolates (75.8%) harbored acc(6')-Ib-cr, qnrD, qnrA, and qnrS genes. Resistance to aminoglycosides, trimethoprim-sulfamethoxazole and chloramphenicol exceeded 80%. Fosfomycin was the most active drug against the tested isolates as only 22.7% were resistant. Class I or II integrons were detected in 86.4% of the isolates. Among class I integron positive isolates, four different gene cassette arrays (dfrA17- aadA5, aadB-aadA2, aadA2-lnuF, and dfrA14-arr-3-blaOXA-10-aadA15) and two gene cassettes (dfrA7 and aadA1) were detected. While class II integron positive isolates carried four different gene cassette arrays (dfrA1-sat1-aadA1, estXVr-sat2-aadA1, lnuF- dfrA1-aadA1, and dfrA1-sat2).

CONCLUSION

P. Mirabilis ability to acquire resistance determinants via integrons may be held responsible for the elevated rates of antimicrobial resistance and emergence of XDR or even PDR strains limiting the available therapeutic options for management of infections caused by those strains.

Multidrug-Resistant Bacteria in Surgical Intensive Care Units: Antibiotic Susceptibility and β-Lactamase Characterization

Multidrug-resistant (MDR) bacteria of the utmost importance are extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacterales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus spp. (VRE). In this study, an evaluation of MDR bacteria in surgical intensive care units in a tertiary referral hospital was conducted. The study aimed to characterize β-lactamases and other resistance traits of Gram-negative bacteria isolated in surgical intensive care units (ICUs). Disk diffusion and the broth dilution method were used for antibiotic susceptibility testing, whereas ESBL screening was performed through a double disk synergy test and an inhibitor-based test with clavulanic acid. A total of 119 MDR bacterial isolates were analysed. ESBL production was observed in half of the Proteus mirabilis, 90% of the Klebsiella pneumoniae and all of the Enterobacter cloacae and Escherichia coli isolates. OXA-48 carbapenemase, carried by the L plasmid, was detected in 34 K. pneumoniae and one E. coli and Enterobacter cloacae complex isolates, whereas NDM occurred sporadically and was identified in three K. pneumoniae isolates. OXA-48 positive isolates coharboured ESBLs belonging to the CTX-M family in all but one isolate. OXA-23 carbapenemase was confirmed in all A. baumannii isolates. The findings of this study provide valuable insight of resistance determinants of Enterobacterales and A. baumannii which will enhance surveillance and intervention strategies that are necessary to curb the ever-growing carbapenem resistance rates.

Co-production of metallo-β-lactamase and OXA-type β-lactamases in carbapenem-resistant Acinetobacter baumannii clinical isolates in North East India

Carbapenem-resistant Acinetobacter baumannii poses a significant threat to public health globally, especially due to its ability to produce multiple carbapenemases, leading to treatment challenges. This study aimed to investigate the antibiotic resistance pattern of carbapenem-resistant A. baumannii isolates collected from different clinical settings in North East India, focusing on their genotypic and phenotypic resistance profiles. A total of 172 multidrug-resistant A. baumannii isolates were collected and subjected to antibiotic susceptibility test using the Kirby-Bauer disk diffusion method. Various phenotypic tests were performed to detect extended-spectrum β-lactamase (ESBL), metallo-β-lactamase (MBL), class C AmpC β-lactamase (AmpC), and carbapenem hydrolyzing class D β-lactamase (CHDL) production among the isolates. Overexpression of carbapenemase and cephalosporinase genes was detected among the isolates through both phenotypic and genotypic investigation. The antibiotic resistance profile of the isolates revealed that all were multidrug-resistant; 25% were extensively drug-resistant, 9.30% were pan-drug-resistant, whereas 91.27% were resistant to carbapenems. In the genotypic investigation, 80.81% of isolates were reported harbouring at least one metallo-β-lactamase encoding gene, with blaNDM being the most prevalent at 70.34%, followed by blaIMP at 51.16% of isolates. Regarding class D carbapenemases, blaOXA-51 and blaOXA-23 genes were detected in all the tested isolates, while blaOXA-24, blaOXA-48, and blaOXA-58 were found in 15.11%, 6.97%, and 1.74% isolates respectively. Further analysis showed that 31.97% of isolates co-harboured ESBL, MBL, AmpC, and CHDL genes, while 31.39% of isolates co-harboured ESBL, MBL, and CHDL genes with or without ISAba1 leading to extensively drug-resistant or pan drug-resistant phenotypes. This study highlights the complex genetic profile and antimicrobial-resistant pattern of the isolates circulating in North East India, emphasizing the urgent need for effective infection control measures and the development of alternative treatment strategies to combat these challenging pathogens.

Antibiotic resistance and virulence profiles of Proteus mirabilis isolated from broiler chickens at abattoir in South Africa

BACKGROUND

Proteus mirabilis has been identified as an important zoonotic pathogen, causing several illnesses such as diarrhoea, keratitis and urinary tract infections.

OBJECTIVE

This study assessed the prevalence of P. mirabilis in broiler chickens, its antibiotic resistance (AR) patterns, ESBL-producing P. mirabilis and the presence of virulence genes.

METHODS

A total of 26 isolates were confirmed as P. mirabilis from 480 pooled broiler chicken faecal samples by polymerase chain reaction (PCR). The disk diffusion method was used to evaluate the antibacterial susceptibility test, while nine virulence genes and 26 AR genes were also screened by PCR.

RESULTS

All 26 P. mirabilis isolates harboured the ireA (siderophore receptors), ptA, and zapA (proteases), ucaA, pmfA, atfA, and mrpA (fimbriae), hlyA and hpmA (haemolysins) virulence genes. The P. mirabilis isolates were resistant to ciprofloxacin (62%) and levofloxacin (54%), while 8 (30.7%) of the isolates were classified as multidrug resistant (MDR). PCR analysis identified the blaCTX-M gene (62%), blaTEM (58%) and blaCTX-M-2 (38%). Further screening for AMR genes identified mcr-1, cat1, cat2, qnrA, qnrD and mecA, 12%, 19%, 12%, 54%, 27% and 8%, respectively for P. mirabilis isolates. The prevalence of the integron integrase intI1 and intI2 genes was 43% and 4%, respectively.

CONCLUSIONS

The rise of ciprofloxacin and levofloxacin resistance, as well as MDR strains, is a public health threat that points to a challenge in the treatment of infections caused by these zoonotic bacteria. Furthermore, because ESBL-producing P. mirabilis has the potential to spread to humans, the presence of blaCTX -M -producing P. mirabilis in broilers should be kept under control. This is the first study undertaken to isolate P. mirabilis from chicken faecal samples and investigate its antibiotic resistance status as well as virulence profiles in South Africa.

Antimicrobial Susceptibility Trends of Proteeae Isolates From a Tertiary-Care Hospital in Western Saudi Arabia

BACKGROUND

The tribe Proteeae comprises Proteus, Providencia, and Morganella species. TheseGram-negative rods are of concern in that they are involved in diverse human infections, particularly in hospital settings. In the last two decades, there has been a sharp increase in infections by multidrug-resistant (MDR) Proteeae. Therefore, the objectives of this study were to: (i) assess the prevalence of infections caused by tribe Proteeae, (ii)determine the antimicrobial susceptibility profile of the test isolates, and (iii) identify the underlying risk factors for acquisition of infection by MDR strains.

METHODS

During the period from January 2019 to December 2020, we conducted a retrospective review of the electronic medical and laboratory records of adult patients who received care at our institution. In addition, we analyzed the risk factors associated with acquisition of infections by members of the tribe Proteeae using univariate and multivariate regression models.

RESULTS

Overall 403 adult patients (average age 59.69 ± 20.33 years) were enrolled into this study (196 males; 48.6%, and 207 females; 51.4%). Proteus mirabilis was the leading pathogen (70.7%; n=285), followed by Morganella morganii (20.1%; n=81), and Providencia species (9.2%; n=37). Most of the isolates were recovered from urine (59.3%; n=239), followed by wound swabs (23.1%; n=93), with the least from blood samples (1.7%; n=7). Out of 403 Proteeae isolates, 27.3% (n=110) were found to be extended-spectrum β-lactamase (ESBL)-producers, whereas 18.4% (n=74) were MDR. Patient's age, concomitant diabetes mellitus (DM), and long hospital stays were independently associated with infection by MDR strains.

CONCLUSION

Infections by MDR Proteeae are leading causes for morbidity in our tertiary-care facility. Strict adherence to infection control precautions, as well as effective implementation of antimicrobial stewardship programs, are crucial to overcome these superbugs.

Antibiotic resistance and virulence genes profiling of Vibrio cholerae and Vibrio mimicus isolates from some seafood collected at the aquatic environment and wet markets in Eastern Cape Province, South Africa

The current study determines the density of Vibrio spp. and isolates V. cholerae and Vibrio mimicus from fish-anatomical-sites, prawn, crab and mussel samples recovered from fish markets, freshwater and brackish water. Virulence and antibiotic resistance profiling of isolates were carried out using standard molecular and microbiology techniques. Vibrio spp. was detected in more than 90% of samples [134/144] and its density was significantly more in fish than in other samples. Vibrio. cholerae and V. mimicus were isolated in at least one sample of each sample type with higher isolation frequency in fish samples. All the V. cholerae isolates belong to non-O1/non-O139 serogroup. One or more V. cholerae isolates exhibited intermediate or resistance against each of the eighteen panels of antibiotics used but 100% of the V. mimicus were susceptible to amikacin, gentamycin and chloramphenicol. Vibrio cholerae exhibited relatively high resistance against polymyxin, ampicillin and amoxicillin/clavulanate while V. mimicus isolates exhibited relatively high resistance against nitrofurantoin, ampicillin and polymixin. The multiple-antibiotic-resistance-index [MARI] for isolates ranges between 0 and 0.67 and 48% of the isolates have MARI that is >0.2 while 55% of the isolates exhibit MultiDrug Resistance Phenotypes. The percentage detection of acc, ant, drf18, sul1, mcr-1, blasvh, blaoxa, blatem, blaoxa48, gyrA, gyrB and parC resistance-associated genes were 2%, 9%, 14%, 7%, 2%, 25%, 7%, 2%, 2%, 32%, 25% and 27% respectively while that for virulence-associated genes in increasing other was ace [2%], tcp [11%], vpi [16%], ompU [34%], toxR [43%], rtxC [70%], rtxA [73%] and hyla [77%]. The study confirmed the potential of environmental non-O1/non-O139 V. cholerae and V. mimicus to cause cholera-like infection and other vibriosis which could be difficult to manage with commonly recommended antibiotics. Thus, regular monitoring of the environment to create necessary awareness for this kind of pathogens is important in the interest of public health.

Genetic analysis of resistance and virulence characteristics of clinical multidrug-resistant Proteus mirabilis isolates

Objective

Proteus mirabilis is the one of most important pathogens of catheter-associated urinary tract infections. The emergence of multidrug-resistant (MDR) P. mirabilis severely limits antibiotic treatments, which poses a public health risk. This study aims to investigate the resistance characteristics and virulence potential for a collection of P. mirabilis clinical isolates.

Methods and results

Antibiotic susceptibility testing revealed fourteen MDR strains, which showed high resistance to most β-lactams and trimethoprim/sulfamethoxazole, and a lesser extent to quinolones. All the MDR strains were sensitive to carbapenems (except imipenem), ceftazidime, and amikacin, and most of them were also sensitive to aminoglycosides. The obtained MDR isolates were sequenced using an Illumina HiSeq. The core genome-based phylogenetic tree reveals the high genetic diversity of these MDR P. mirabilis isolates and highlights the possibility of clonal spread of them across China. Mobile genetic elements SXT/R391 ICEs were commonly (10/14) detected in these MDR P. mirabilis strains, whereas the presence of resistance island PmGRI1 and plasmid was sporadic. All ICEs except for ICEPmiChn31006 carried abundant antimicrobial resistance genes (ARGs) in the HS4 region, including the extended-spectrum β-lactamase (ESBL) gene blaCTX-M-65. ICEPmiChn31006 contained the sole ARG blaCMY-2 and was nearly identical to the global epidemic ICEPmiJpn1. The findings highlight the important roles of ICEs in mediating the spread of ARGs in P. mirabilis strains. Additionally, these MDR P. mirabilis strains have great virulence potential as they exhibited significant virulence-related phenotypes including strong crystalline biofilm, hemolysis, urease production, and robust swarming motility, and harbored abundant virulence genes.

Conclusion

In conclusion, the prevalence of MDR P. mirabilis with high virulence potential poses an urgent threat to public health. Intensive monitoring is needed to reduce the incidence of infections by MDR P. mirabilis.

Synthesis and photodynamic antimicrobial chemotherapy against multi-drug resistant Proteus mirabilis of ornithine-porphyrin conjugates in vitro and in vivo

For the treatment of bacterial infections, photodynamic antimicrobial chemotherapy (PACT) has the advantage of circumventing multi-drug resistance. In this work, new cationic photosensitizers against multi-drug resistant Proteus mirabilis (MRPM) were designed and synthesized by the conjugation of amino phenyl porphyrin with basic amino acid L-ornithine. Their photoinactivation efficacies against MRPM in vitro were reported and include the influence of laser energy, uptake, MIC and MBC, dose-dependent photoinactivation effects, membrane integrity, and fluorescence imaging. The PACT in vivo was evaluated using a wound mouse model infected by MRPM. Photosensitizer 4d displayed high photo inactivation efficacy against MRPM at 7.81 μM under illumination, and it could accelerate wound healing via bactericidal effect. These ornithine-porphyrin conjugates are potential photosensitizers for PACT in the treatment of MRPM infection.

Occurrence of Carbapenemases, Extended-Spectrum Beta-Lactamases and AmpCs among Beta-Lactamase-Producing Gram-Negative Bacteria from Clinical Sources in Accra, Ghana

Beta-lactamase (β-lactamase)-producing Gram-negative bacteria (GNB) are of public health concern due to their resistance to routine antimicrobials. We investigated the antimicrobial resistance and occurrence of carbapenemases, extended-spectrum β-lactamases (ESBLs) and AmpCs among GNB from clinical sources. GNB were identified using matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDITOF-MS). Antimicrobial susceptibility testing was performed via Kirby-Bauer disk diffusion and a microscan autoSCAN system. β-lactamase genes were determined via multiplex polymerase chain reactions. Of the 181 archived GNB analyzed, Escherichia coli and Klebsiella pneumoniae constituted 46% (n = 83) and 17% (n = 30), respectively. Resistance to ampicillin (51%), third-generation cephalosporins (21%), and ertapenem (21%) was observed among the isolates, with 44% being multi-drug resistant (MDR). β-lactamase genes such as AmpCs ((bla_FOX-M (64%) and bla_DHA-M and bla_EDC-M (27%)), ESBLs ((bla_CTX-M (81%), other β-lactamase genes bla_TEM (73%) and bla_SHV (27%)) and carbapenemase ((bla_OXA-48 (60%) and bla_NDM and bla_KPC (40%)) were also detected. One K. pneumoniae co-harbored AmpC (bla_FOX-M and bla_EBC-M) and carbapenemase (bla_KPC and bla_OXA-48) genes. bla_OXA-48 gene was detected in one carbapenem-resistant Acinetobacter baumannii. Overall, isolates were resistant to a wide range of antimicrobials including last-line treatment options. This underpins the need for continuous surveillance for effective management of infections caused by these pathogens in our settings.