Prevalence of meropenem-resistant Pseudomonas Aeruginosa in Ethiopia: a systematic review and meta­analysis.

INTRODUCTION: Antimicrobial resistance (AMR) is a pressing global health concern, particularly pronounced in low-resource settings. In Ethiopia, the escalating prevalence of carbapenem-resistant Pseudomonas aeruginosa (P. aeruginosa) poses a substantial threat to public health. METHODS: A comprehensive search of databases, including PubMed, Scopus, Embase, Hinari, and Google Scholar, identified relevant studies. Inclusion criteria encompassed observational studies reporting the prevalence of meropenem-resistant P. aeruginosa in Ethiopia. Quality assessment utilized JBI checklists. A random-effects meta-analysis pooled data on study characteristics and prevalence estimates, with subsequent subgroup and sensitivity analyses. Publication bias was assessed graphically and statistically. RESULTS: Out of 433 studies, nineteen, comprising a total sample of 11,131, met inclusion criteria. The pooled prevalence of meropenem-resistant P. aeruginosa was 15% (95% CI: 10-21%). Significant heterogeneity (I2 = 83.6%) was observed, with the number of P. aeruginosa isolates identified as the primary source of heterogeneity (p = 0.127). Subgroup analysis by infection source revealed a higher prevalence in hospital-acquired infections (28%, 95% CI: 10, 46) compared to community settings (6%, 95% CI: 2, 11). Geographic based subgroup analysis indicated the highest prevalence in the Amhara region (23%, 95% CI: 8, 38), followed by Addis Ababa (21%, 95% CI: 11, 32), and lower prevalence in the Oromia region (7%, 95% CI: 4, 19). Wound samples exhibited the highest resistance (25%, 95% CI: 25, 78), while sputum samples showed the lowest prevalence. Publication bias, identified through funnel plot examination and Egger's regression test (p < 0.001), execution of trim and fill analysis resulted in an adjusted pooled prevalence of (3.7%, 95% CI: 2.3, 9.6). CONCLUSION: The noteworthy prevalence of meropenem resistance among P. aeruginosa isolates in Ethiopia, particularly in healthcare settings, underscores the urgency of implementing strict infection control practices and antibiotic stewardship. Further research is imperative to address and mitigate the challenges posed by antimicrobial resistance in the country.

Characterization of ß-lactamase and virulence genes in Pseudomonas aeruginosa isolated from clinical, environmental and poultry sources in Bangladesh.

The emergence and spread of multidrug-resistant pathogens like Pseudomonas aeruginosa are major concerns for public health worldwide. This study aimed to assess the prevalence of P. aeruginosa in clinical, environmental, and poultry sources in Bangladesh, along with their antibiotic susceptibility and the profiling of ß-lactamase and virulence genes using standard molecular and microbiology techniques. We collected 110 samples from five different locations, viz., BAU residential area (BAURA; n = 15), BAU Healthcare Center (BAUHCC; n = 20), BAU Veterinary Teaching Hospital (BAUVTH; n = 22), Poultry Market (PM; n = 30) and Mymensingh Medical College Hospital (MCCH; n = 23). After overnight enrichment in nutrient broth, 89 probable Pseudomonas isolates (80.90%) were screened through selective culture, gram-staining and biochemical tests. Using genus- and species-specific PCR, we confirmed 22 isolates (20.0%) as P. aeruginosa from these samples. Antibiogram profiling revealed that 100.0% P. aeruginosa isolates (n = 22) were multidrug-resistant isolates, showing resistance against Doripenem, Penicillin, Ceftazidime, Cefepime, and Imipenem. Furthermore, resistance to aztreonam was observed in 95.45% isolates. However, P. aeruginosa isolates showed a varying degree of sensitivity against Amikacin, Gentamicin, and Ciprofloxacin. The blaTEM gene was detected in 86.0% isolates, while blaCMY, blaSHV and blaOXA, were detected in 27.0%, 18.0% and 5.0% of the P. aeruginosa isolates, respectively. The algD gene was detected in 32.0% isolates, whereas lasB and exoA genes were identified in 9.0% and 5.0% P. aeruginosa isolates. However, none of the P. aeruginosa isolates harbored exoS gene. Hence, this study provides valuable and novel insights on the resistance and virulence of circulating P. aeruginosa within the clinical, environmental, and poultry environments of Bangladesh. These findings are crucial for understanding the emergence of ß-lactamase resistance in P. aeruginosa, highlighting its usefulness in the treatment and control of P. aeruginosa infections in both human and animal populations.

Antimicrobial resistance and carbapenemase dissemination in Pseudomonas aeruginosa isolates from Libyan hospitals: a call for surveillance and intervention.

Pseudomonas aeruginosa is a multidrug-resistant bacterium capable of forming biofilms. This study aimed to assess resistance of clinical isolates from Libyan hospitals to antipseudomonal antibiotics, the prevalence of selected extended-spectrum ß-lactamases and carbapenemase genes among these isolates, and the microorganisms' capacity for alginate and biofilm production. Forty-five isolates were collected from four hospitals in Benghazi and Derna, Libya. Antimicrobial susceptibility was determined using agar disc diffusion. The presence of resistance genes (blaCTXM, blaTEM, blaSHV-1, blaGES-1, blaKPC, and blaNDM) was screened using PCR. Biofilm formation was quantified via the crystal violet assay, while alginate production was measured spectrophotometrically. Resistance to antipseudomonal antibiotics ranged from 48.9% to 75.6%. The most prevalent resistance gene was blaNDM (26.7%), followed by blaGES-1 (17.8%). Moreover, all isolates demonstrated varying degrees of biofilm-forming ability and alginate production. No statistically significant correlation was found between biofilm formation and alginate production. The dissemination of resistant genes in P. aeruginosa, particularly carbapenemases, is of great concern. This issue is compounded by the bacteria's biofilm-forming capability. Urgent intervention and continuous surveillance are imperative to prevent further deterioration and the catastrophic spread of resistance among these formidable bacteria.

Phenotypic and genotypic characterization of resistance and virulence in Pseudomonas aeruginosa isolated from poultry farms in Egypt using whole genome sequencing.

Pseudomonas aeruginosa (P. aeruginosa) is an ESKAPE pathogen that can quickly develop resistance to most antibiotics. This bacterium is a zoonotic pathogen that can be found in humans, animals, foods, and environmental samples, making it a One-Health concern. P. aeruginosa threatens the poultry industry in Egypt, leading to significant economic losses. However, the investigation of this bacterium using NGS technology is nearly non-existent in Egypt. In this study, 38 isolates obtained from broiler farms of the Delta region were phenotypically investigated, and their genomes were characterized using whole genome sequencing (WGS). The study found that 100% of the isolates were resistant to fosfomycin and harbored the fosA gene. They were also resistant to trimethoprim/sulfamethoxazole, although only one isolate harbored the sul1 gene. Non-susceptibility (resistant, susceptible with increased dose) of colistin was observed in all isolates. WGS analysis revealed a high level of diversity between isolates, and MLST analysis allocated the 38 P. aeruginosa isolates into 11 distinct sequence types. The most predominant sequence type was ST267, found in 13 isolates, followed by ST1395 in 8 isolates. The isolates were susceptible to almost all tested antibiotics carrying only few different antimicrobial resistance (AMR) genes. Various AMR genes that confer resistance mainly to ß-lactam, aminoglycoside, sulfonamide, and phenicol compounds were identified. Additionally, several virulence associated genes were found without any significant differences in number and distribution among isolates. The majority of the virulence genes was identified in almost all isolates. The fact that P. aeruginosa, which harbors several AMR and virulence-associated factors, is present in poultry farms is alarming and threatens public health. The misuse of antimicrobial compounds in poultry farms plays a significant role in resistance development. Thus, increasing awareness and implementing strict veterinary regulations to guide the use of veterinary antibiotics is required to reduce health and environmental risks. Further studies from a One-Health perspective using WGS are necessary to trace the potential transmission routes of resistance between animals and humans and clarify resistance mechanisms.

Eye infection risks from Pseudomonas aeruginosa via hand soap and eye drops.

Eye infections from bacterial contamination of bulk-refillable liquid soap dispensers and artificial tear eye drops continue to occur, resulting in adverse health outcomes that include impaired vision or eye enucleation. Pseudomonas aeruginosa (P. aeruginosa), a common cause of eye infections, can grow in eye drop containers and refillable soap dispensers to high numbers. To assess the risk of eye infection, a quantitative microbial risk assessment for P. aeruginosa was conducted to predict the probability of an eye infection for two potential exposure scenarios: (i) individuals using bacteria-contaminated eye drops and (ii) contact lens wearers washing their hands with bacteria-contaminated liquid soap prior to placing the lens. The median risk of an eye infection using contaminated eye drops and hand soap for both single and multiple exposure events (per day) ranged from 10-1 to 10-4, with contaminated eye drops having the greater risk. The concentration of P. aeruginosa was identified as the parameter contributing the greatest variance on eye infection risk; therefore, the prevalence and level of bacterial contamination of the product would have the greatest influence on health risk. Using eye drops in a single-use container or with preservatives can mitigate bacterial growth, and using non-refillable soap dispensers is recommended to reduce contamination of hand soap. Given the opportunistic nature of P. aeruginosa and its ability to thrive in unique environments, additional safeguards to mitigate bacterial growth and exposure are warranted.IMPORTANCEPseudomonas aeruginosa (P. aeruginosa) is a pathogen that can persist in a variety of unusual environments and continues to pose a significant risk for public health. This quantitative microbial risk assessment (QMRA) estimates the potential human health risks, specifically for eye infections, associated with exposure to P. aeruginosa in bacteria-contaminated artificial tear eye drops and hand soap. This study applies the risk assessment framework of QMRA to evaluate eye infection risks through both consumer products. The study examines the prevalence of this pathogen in eye drops and soap, as well as the critical need to implement measures that will mitigate bacterial exposure (e.g., single-use soap dispensers and eye drops with preservatives). Additionally, limitations and challenges are discussed, including the need to incorporate data regarding consumer practices, which may improve exposure assessments and health risk estimates.

Epidemiology and risk factors for extension of necrotizing otitis externa.

PURPOSE: Necrotizing otitis externa (OEN) is an aggressive and morbid infection of the external acoustic meatus. What are the risk factors for OEN extension? METHODS: French monocentric retrospective study (2004-2021), including patients with OEN defined by the association of an inflamed EAM, a positive nuclear imaging, the presence of a bacteriological sample and the failure of a well-followed local and/or general antibiotic treatment. OEN was extensive if it was associated with vascular or neurological deficits, if nuclear imaging fixation and/or bone lysis extended beyond the tympanic bone. RESULTS: Our population (n = 39) was male (74%), type 2 diabetic (72%), aged 75.2 years and pseudomonas aeruginosa was found in 88% of cases. Complications for 43% of patients were extensive fixation on nuclear imaging, for 21% of them the presence of extensive bone lysis, for 13% the appearance of facial palsy, for 5.3% the presence hypoglossal nerve palsy and for 2.5% the presence of thrombophlebitis or other nerves palsies. 59% of our population had extensive OEN. The diagnosis of the extensive OEN was made 22 days later (p = 0.04). The clinical presentation was falsely reassuring due to easier identification of the tympanic membrane (70% vs 46%, p = 0.17) but associated with periauricular oedema (42% vs 0%), bone exposure (16% vs 0%) and a temporomandibular joint pain (41% vs 12%). CONCLUSION: Delayed treatment of OEN, identification of clinical bone lysis, especially when the tympanic membrane is easily visualized, and the presence of unbalanced diabetes are potential risk factors for extension of OEN.

Prevalence and antimicrobial-resistant patterns of Pseudomonas aeruginosa among burn patients attending Yekatit 12 Hospital Medical College in Addis Ababa, Ethiopia.

BACKGROUND: Burns are one of the most common forms of trauma globally. P. aeruginosa plays a prominent role as an etiological agent among burn patients. There is a paucity of information about the prevalence and antimicrobial resistance patterns of P. aeruginosa among burn patients in Ethiopia. Hence, this study was designed to assess the prevalence and antimicrobial-resistant patterns of P. aeruginosa among burn patients attending Yekatit 12 Hospital Medical College in Addis Ababa, Ethiopia. METHODS: Hospital-based cross-sectional study was conducted at Yekatit 12 Hospital Medical College among burn patients from November 2020 to April 2021. Identification of P. aeruginosa was performed using Culture, Biochemical tests, and, Gram staining. Antimicrobial resistance testing was done using the Kirby-Bauer disc diffusion method. Logistic regression was computed to determine associated factors. RESULTS: From 210 burn wound cultures, 27 (12.86%) were found positive for P. aeruginosa. All the isolates showed greater than 70% susceptibility to the tested antibiotics except Gentamycin, Ceftazidime, and, Ciprofloxacin. In addition, 33.33% of P. aeruginosa isolates were multidrug-resistant. Admission type, Hospital stay time and Total body surface area (TBSA) had a statistically significant association (all with P-value <0.05) with the acquisition of P. aeruginosa infection. CONCLUSION: Overall, the prevalence of P. aeruginosa isolates among burn patients is almost 13%. Most P. aeruginosa isolates were sensitive to Imipenem, while they were most resistant to Gentamycin. One-third of P. aeruginosa were multidrug-resistant. This suggests the need to monitor the treatment of infection with the pathogen to limit the possibility of the emergence of multidrug-resistant isolates in burn centers.

Significant role of pyocyanin and exotoxin A in the pathogenesis of Pseudomonas aeruginosa isolated from hospitalized patients.

AIM: Due to the importance of exotoxin A and pyocyanin in the pathogenicity of this bacterium, we decided to evaluate the prevalence of genes encoding these virulence factors in clinical isolates of P.aeruginosa.

Comparative analysis of antibiotic susceptibility patterns and clinical features of mucoid and non-mucoid Pseudomonas aeruginosa infections: a retrospective study.

Background: Pseudomonas aeruginosa (PA) is a prevalent opportunistic pathogen that has close associations with both acute and chronic infections. However, there exists an insufficiency of accurate and comprehensive data pertaining to the antimicrobial susceptibility patterns and clinical characteristics of both mucoid and non-mucoid strains of PA (mPA and non-mPA, respectively). Methods: From January 1, 2021 to December 31, 2022, a thorough retrospective study was carried out to examine and compare the antibiotic susceptibility test outcomes and clinical characteristics of hospitalized patients with mPA and non-mPA infections. Results: This study investigated a cohort of 111 patients who were diagnosed with mPA infections, as well as 792 patients diagnosed with non-mPA infections. Significant demographic disparities, including gender (p < 0.001), age (p < 0.001), length of hospital stay (p < 0.001), diabetes (p = 0.043), and hypertension (p < 0.001), are evident between the mPA and non-mPA groups. The mPA group commonly necessitates hospitalization for respiratory system diseases, whereas the non-mPA group is associated with concomitant cardiovascular and cerebrovascular diseases. The mPA group demonstrates lower utilization rates of medical devices, such as Foley catheter (p < 0.001), nasogastric tube (p < 0.001), mechanical ventilation (p < 0.001), tracheostomy (p < 0.001), arterial and venous catheterization (p < 0.001), and exhibits superior organ function status, including lower incidences of hypoalbuminemia (p < 0.001), septic shock (p < 0.001), liver dysfunction (p < 0.001), renal failure (p < 0.001), and respiratory failure (p < 0.001). The non-mPA group is more vulnerable to infection with two or more bacterial pathogens compared to the mPA group, with the non-mPA group frequently resulting in Enterobacteriaceae infections and the mPA group being associated with fungal infections. Variations in antibiotic sensitivity are noted for Amikacin (p < 0.001), Ciprofloxacin (p < 0.001), Cefepime (p = 0.003), and Levofloxacin (p < 0.001) in antibiotic susceptibility testing, with resistance patterns closely tied to specific antibiotic usage. Conclusion: There are significant demographic characteristics, clinical manifestations and antibiotic susceptibility between mPA and non-mPA infections. It is crucial to emphasize these characteristics due to their significant role in preventing and treating PA infections.

Molecular characterization of extensively drug-resistant hypervirulent Pseudomonas aeruginosa isolates in China.

BACKGROUND: Recently, extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) isolates have been increasingly detected and posed great challenges to clinical anti-infection treatments. However, little is known about extensively resistant hypervirulent P. aeruginosa (XDR-hvPA). In this study, we investigate its epidemiological characteristics and provide important basis for preventing its dissemination. METHODS: Clinical XDR-PA isolates were collected from January 2018 to January 2023 and identified using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry; antibiotic susceptibility testing was performed by broth microdilution method, and minimum inhibitory concentrations (MICs) were evaluated. Virulence was evaluated using the Galleria mellonella infection model; molecular characteristics, including resistance genes, virulence genes, and homology, were determined using whole-genome sequencing. RESULTS: A total of 77 XDR-PA strains were collected; 47/77 strains were XDR-hvPA. Patients aged > 60 years showed a significantly higher detection rate of XDR-hvPA than of XDR-non-hvPA. Among the 47 XDR-hvPA strains, 24 strains carried a carbapenemase gene, including blaGES-1 (10/47), blaVIM-2 (6/47), blaGES-14 (4/47), blaIMP-45 (2/47), blaKPC-2 (1/47), and blaNDM-14 (1/47). ExoU, exoT, exoY, and exoS, important virulence factors of PA, were found in 31/47, 47/47, 46/47, and 29/47 strains, respectively. Notably, two XDR-hvPA simultaneously co-carried exoU and exoS. Six serotypes (O1, O4-O7, and O11) were detected; O11 (19/47), O7 (13/47), and O4 (9/47) were the most prevalent. In 2018-2020, O4 and O7 were the most prevalent serotypes; 2021 onward, O11 (16/26) was the most prevalent serotype. Fourteen types of ST were detected, mainly ST235 (14/47), ST1158 (13/47), and ST1800 (7/47). Five global epidemic ST235 XDR-hvPA carried blaGES and showed the MIC value of ceftazidime/avibactam reached the susceptibility breakpoint (8/4 mg/L). CONCLUSIONS: The clinical detection rate of XDR-hvPA is unexpectedly high, particularly in patients aged > 60 years, who are seemingly more susceptible to contracting this infection. Clonal transmission of XDR-hvPA carrying blaGES, which belongs to the global epidemic ST235, was noted. Therefore, the monitoring of XDR-hvPA should be strengthened, particularly for elderly hospitalized patients, to prevent its spread.

Antimicrobial resistance survey and whole-genome analysis of nosocomial P. Aeruginosa isolated from eastern Province of China in 2016-2021.

BACKGROUND: Pseudomonas aeruginosa is a major Gram-negative pathogen that can exacerbate lung infections in the patients with cystic fibrosis, which can ultimately lead to death. METHODS: From 2016 to 2021, 103 strains of P. aeruginosa were isolated from hospitals and 20 antibiotics were used for antimicrobial susceptibility determination. Using next-generation genome sequencing technology, these strains were sequenced and analyzed in terms of serotypes, ST types, and resistance genes for epidemiological investigation. RESULTS: The age distribution of patients ranged from 10 days to 94 years with a median age of 69 years old. The strains were mainly isolated from sputum (72 strains, 69.9%) and blood (14 strains, 13.6%). The size of these genomes ranged from 6.2 Mb to 7.4 Mb, with a mean value of 6.5 Mb. In addition to eight antibiotics that show inherent resistance to P. aeruginosa, the sensitivity rates for colistin, amikacin, gentamicin, ceftazidime, piperacillin, piperacillin-tazobactam, ciprofloxacin, meropenem, aztreonam, imipenem, cefepime and levofloxacin were 100%, 95.15%, 86.41%, 72.82%, 71.84%, 69.90%, 55.34%, 52.43%, 50.49%, 50.49%, 49.51% and 47.57% respectively, and the carriage rate of MDR strains was 30.69% (31/101). Whole-genome analysis showed that a total of 50 ST types were identified, with ST244 (5/103) and ST1076 (4/103) having a more pronounced distribution advantage. Serotype predictions showed that O6 accounted for 29.13% (30/103), O11 for 23.30% (24/103), O2 for 18.45% (19/103), and O1 for 11.65% (12/103) of the highest proportions. Notably, we found a significantly higher proportion of ExoU in P. aeruginosa strains of serotype O11 than in other cytotoxic exoenzyme positive strains. In addition to this, a total of 47 crpP genes that mediate resistance to fluoroquinolones antibiotics were found distributed on 43 P. aeruginosa strains, and 10 new variants of CrpP were identified, named 1.33, 1.34, 1.35, 1.36, 1.37, 1.38, 1.39, 1.40, 1.41 and 7.1. CONCLUSIONS: We investigated the antibiotic susceptibility of clinical isolates of P. aeruginosa and genomically enriched the diversity of P. aeruginosa for its prophylactic and therapeutic value.

Genomic epidemiology and ceftazidime-avibactam high-level resistance mechanisms of Pseudomonas aeruginosa in China from 2010 to 2022.

Ceftazidime-avibactam (CZA) resistance is a huge threat in the clinic; however, the underlying mechanism responsible for high-level CZA resistance in Pseudomonas aeruginosa (PA) isolates remains unknown. In this study, a total of 5,763 P. aeruginosa isolates were collected from 2010 to 2022 to investigate the ceftazidime-avibactam (CZA) high-level resistance mechanisms of Pseudomonas aeruginosa (PA) isolates in China. Fifty-six PER-producing isolates were identified, including 50 isolates carrying blaPER-1 in PA, and 6 isolates carrying blaPER-4. Of these, 82.1% (46/56) were classified as DTR-PA isolates, and 76.79% (43/56) were resistant to CZA. Importantly, blaPER-1 and blaPER-4 overexpression led to 16-fold and >1024-fold increases in the MICs of CZA, respectively. WGS revealed that the blaPER-1 gene was located in two different transferable IncP-2-type plasmids and chromosomes, whereas blaPER-4 was found only on chromosomes and was carried by a class 1 integron embedded in a Tn6485-like transposon. Overexpression of efflux pumps may be associated with high-level CZA resistance in blaPER-1-positive strains. Kinetic parameter analysis revealed that PER-4 exhibited a similar kcat/Km with ceftazidime and a high (∼3359-fold) IC50 value with avibactam compared to PER-1. Our study found that overexpression of PER-1 combined with enhanced efflux pump expression and the low affinity of PER-4 for avibactam contributes to high-level resistance to CZA. Additionally, the Tn6485-like transposon plays a significant role in disseminating blaPER. Urgent active surveillance is required to prevent the further spread of high-level CZA resistance in DTR-PA isolates.

A fractional-order model for nosocomial infection caused by Pseudomonas aeruginosa in Northern Cyprus.

Pseudomonas aeruginosa, a resilient gram-negative bacterium, poses a persistent threat as a leading cause of nosocomial infections, particularly in resource-constrained regions. Despite existing treatment and control measures, the bacterium continues to challenge healthcare systems, especially in developing nations. This paper introduces a fractional-order model to elucidate the dynamic behavior of nosocomial infections caused by P. aeruginosa and to compare the efficacy of carbapenems and aminoglycosides in treatment. The model's existence and uniqueness are established, and both global and local stability are confirmed. The effective reproduction number is computed, revealing an epidemic potential with a value of 1.02 in Northern Cyprus. Utilizing real-life data from a university hospital and employing numerical simulations, our results indicate that patients exhibit higher sensitivity and lower resistance to aminoglycoside treatment compared to carbapenems. Aminoglycosides consistently outperform carbapenems across key metrics, including the reduction of susceptible population, infection numbers, treatment efficacy, total infected population, hospital occupancy, and effective reproduction number. The fractional-order approach emerges as a suitable and insightful tool for studying the transmission dynamics of the disease and assessing treatment effectiveness. This research provides a robust foundation for refining treatment strategies against P. aeruginosa infections, contributing valuable insights for healthcare practitioners and policymakers alike.

Prevalence and molecular characteristics of ceftazidime-avibactam resistance among carbapenem-resistant Pseudomonas aeruginosa clinical isolates.

OBJECTIVES: Resistance against ceftazidime-avibactam (CZA) in carbapenem-resistant Pseudomonas aeruginosa (CRPA) is emerging. This study was aimed at detecting the prevalence and molecular characteristics of CZA-resistant CRPA clinical isolates in Guangdong Province, China. METHODS: The antimicrobial susceptibility profile of these strains was determined. A subset of 16 CZA-resistant CRPA isolates was analysed by whole-genome sequencing (WGS). Genetic surroundings of carbapenem resistance genes and pan-genome-wide association analysis were further studied. RESULTS: Of the 250 CRPA isolates, CZA resistance rate was 6.4% (16/250). The minimum inhibitory concentration (MIC) of CZA range was from 0.25 to >256 mg/L. MIC50 and MIC90 were 2/4 and 8/4 mg/L, respectively. Among the 16 CZA-resistant CRPA strains, 31.3% (5/16) of them carried class B carbapenem resistance genes, including blaIMP-4, blaIMP-45, and blaVIM-2, located on IncP-2 megaplasmids or chromosomes, respectively. Pan-genome-wide association analysis of accessory genes for CZA-susceptible or -resistant CRPA isolates showed that PA1874, a hypothetical protein containing BapA prefix-like domain, was enriched in CZA-resistant group significantly. CONCLUSIONS: Class B carbapenem resistance genes play important roles in CZA resistance. Meanwhile, the PA1874 gene may be a novel mechanism involving in CZA resistance. It is necessary to continually monitor CZA-resistant CRPA isolates.

Pseudomonas Infection Outbreak Associated with a Hotel Swimming Pool - Maine, March 2023.

Treated recreational water venues (e.g., pools and hot tubs) located at hotels represent one third of sources of reported treated recreational water-associated outbreaks; when these outbreaks are caused by Pseudomonas aeruginosa, they predominantly occur during January-April. On March 8, 2023, the Maine Center for Disease Control and Prevention (Maine CDC) initiated an investigation in response to reports of illness among persons who had used a swimming pool at hotel A during March 4-5. A questionnaire was distributed to guests who were at hotel A during March 1-7. Among 35 guests who responded, 23 (66%) developed ear pain, rash, or pain or swelling in feet or hands within days of using the pool during March 4-5. P. aeruginosa, a chlorine-susceptible bacterium, was identified in cultures obtained from skin lesions of three patients; a difference of two single nucleotide polymorphisms was found between isolates from two patients' specimens, suggesting a common exposure. Hotel A management voluntarily closed the pool, and Maine CDC's Health Inspection Program identified multiple violations, including having no disinfectant feeder system, all of which had been identified during a previous inspection. Because chlorine had been added to the pool water after the pool was voluntary closed, environmental samples were not collected. The pool remained closed until violations were addressed. Health departments can play an important role in reducing the risk for outbreaks associated with hotel pools and hot tubs. This reduction in risk can be achieved by collaborating with operators to ensure compliance with public health codes, including maintaining chlorine concentration and otherwise vigilantly managing the pool, and by disseminating prevention messages to pool and hot tub users.

Drug susceptibility, Prevalence and effect of Pseudomonas aeruginosa on wound healing of burn patients.

Objective: To determine the prevalence, antibiotic susceptibility and effect of Pseudomonas aeruginosa in relation to burn patients. METHODS: The cross-sectional study was conducted at the Centre for Advanced Studies in Vaccinology and Biotechnology, University of Balochistan, Quetta, Pakistan, from March 2018 to May 2021, and comprised pus swab cultures were isolated from inpatients with 2nd and 3rd degree burns aged up to 60 years at Bolan Medical Complex Hospital and Sandeman Provinical Hospital, the two main government tertiary care hospitals in Quetta. The samples were immediately cultured, and evaluated using biochemical tests, antibiotic susceptibility and molecular identification using polymerase chain reaction. Data was analysed using SPSS 20. RESULTS: Of the 720 burn wound samples, 424(58.9%) were positive for Pseudomonas aeruginosa; 304(42%) males and 120(16%) females (p<0.02). The overall mean age of the patients was 27.7±6.2 years (range: 1-60 years). The mean total burn surface area was not significantly different in positive 29.6±6.2% and negative 30.3±6.2% cases (p>0.05). The time leading to skin grafts in positive patients was 29.5±6.5 days compared to 22.3±6.3 days for negative patients (p< 0.007), and the time required for wound healing was 25.0±4.7 days and 16.7±5.2 days, respectively (p<0.001). Length of hospital stay of Pseudomonas aeruginosa positive patients was 38.0±7.8 days compared to 32.1±6.8 days for negative patients (p<0.001). Conclusion: Nosocomial infections and multidrug resistance species were observed frequently at the burn wound site. P. aeruginosa.

Two Artificial Tears Outbreak-Associated Cases of Extensively Drug-Resistant Pseudomonas aeruginosa Detected Through Whole Genome Sequencing-Based Surveillance.

We describe 2 cases of extensively drug-resistant Pseudomonas aeruginosa infection caused by a strain of public health concern, as it was recently associated with a nationwide outbreak of contaminated artificial tears. Both cases were detected through database review of genomes in the Enhanced Detection System for Hospital-Associated Transmission (EDS-HAT), a routine genome sequencing-based surveillance program. We generated a high-quality reference genome for the outbreak strain from an isolate from our center and examined the mobile elements encoding blaVIM-80 and bla-GES-9 carbapenemases. We used publicly available Pseudomonas aeruginosa genomes to explore the genetic relatedness and antimicrobial resistance genes of the outbreak strain.

The global epidemiology of ventilator-associated pneumonia caused by multi-drug resistant Pseudomonas aeruginosa: A systematic review and meta-analysis.

OBJECTIVES: The objective of this systematic review and meta-analysis was to estimate the global prevalence of multi-drug resistant (MDR) Pseudomonas aeruginosa causing ventilator-associated pneumonia (VAP). METHODS: The systematic search was conducted in four databases. Original studies describing MDR P. aeruginosa VAP prevalence in adults from 2012- 2022 were included. A meta-analysis, using the random effects model, was conducted for overall, subgroups (country, published year, study duration, and study design), and European data, respectively. Univariate meta-regression based on pooled estimates was also conducted. Systematic review registered in International Prospective Register of Systematic Review (CRD42022384035). RESULTS: In total of 31 studies, containing a total of 7951 cases from 16 countries, were included. The overall pooled prevalence of MDR among P. aeruginosa causing VAP was 33% (95% confidence interval [CI] 27.7-38.3%). The highest prevalence was for Iran at 87.5% (95% CI 69-95.7%), and the lowest was for the USA at 19.7% (95% CI 18.6-20.7%). The European prevalence was 29.9% (95% CI 23.2-36.7%). CONCLUSIONS: This review indicates that the prevalence of MDR P. aeruginosa in patients with VAP is generally high and varies significantly between countries; however, data are insufficient for many countries. The data in this study can provide a reference for VAP management and drug customisation strategies.

In vitro evaluation of biofilm phenotypic and genotypic characteristics among clinical isolates of Pseudomonas aeruginosa in Hamadan, West of Iran.

Due to high antimicrobial resistance and biofilm-forming ability, Pseudomonas aeruginosa is one of the seriously life-threatening agents causing chronic and nosocomial infections. This study was performed to determine the antibiotic resistance pattern, biofilm formation, and frequency of biofilm-related genes in P. aeruginosa strains. In total, 123 P. aeruginosa isolates were collected from different clinical sources. Antimicrobial susceptibility testing (AST) was performed to detect multidrug-resistant P. aeruginosa (MDRPA) isolates. To evaluate the biofilm-forming isolates, the microtiter plate (MTP) method was carried out. Also, the prevalence of biofilm genotype patterns, including pslA, pslD, pelA, pelF, and algD genes, was detected by polymerases chain reaction (PCR). According to our findings, the highest resistance and susceptibility rates were found in ceftazidime with 74.7% (n = 92) and ciprofloxacin with 42.2% (n = 52), respectively. In our study, the highest level of antibiotic resistance belonged to wound isolates which meropenem had the most antibacterial activity against them. In total, 86.1% (n = 106) P. aeruginosa isolates were determined as MDRPA, of which 61.3% (n = 65) were able to form strong biofilm. The highest and lowest frequency of biofilm-related genes among biofilm producer isolates belonged to pelF with 82.1% (n = 101) and algD with 55.2% (n = 68), respectively. The findings of the conducted study indicate a significant relationship between MDRPA and biofilm genotypic/phenotypic patterns, suggesting the necessity of a careful surveillance program in hospital settings.

Pseudomonasaeruginosa antimicrobial susceptibility profiles, resistance mechanisms and international clonal lineages: update from ESGARS-ESCMID/ISARPAE Group.

SCOPE: Pseudomonas aeruginosa, a ubiquitous opportunistic pathogen considered one of the paradigms of antimicrobial resistance, is among the main causes of hospital-acquired and chronic infections associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of P. aeruginosa to develop antimicrobial resistance through chromosomal mutations, the increasing prevalence of transferable resistance determinants (such as the carbapenemases and the extended-spectrum ß-lactamases), and the global expansion of epidemic lineages. The general objective of this initiative is to provide a comprehensive update of P. aeruginosa resistance mechanisms, especially for the extensively drug-resistant (XDR)/difficult-to-treat resistance (DTR) international high-risk epidemic lineages, and how the recently approved ß-lactams and ß-lactam/ß-lactamase inhibitor combinations may affect resistance mechanisms and the definition of susceptibility profiles. METHODS: To address this challenge, the European Study Group for Antimicrobial Resistance Surveillance (ESGARS) from the European Society of Clinical Microbiology and Infectious Diseases launched the 'Improving Surveillance of Antibiotic-Resistant Pseudomonas aeruginosa in Europe (ISARPAE)' initiative in 2022, supported by the Joint programming initiative on antimicrobial resistance network call and included a panel of over 40 researchers from 18 European Countries. Thus, a ESGARS-ISARPAE position paper was designed and the final version agreed after four rounds of revision and discussion by all panel members. QUESTIONS ADDRESSED IN THE POSITION PAPER: To provide an update on (a) the emerging resistance mechanisms to classical and novel anti-pseudomonal agents, with a particular focus on ß-lactams, (b) the susceptibility profiles associated with the most relevant ß-lactam resistance mechanisms, (c) the impact of the novel agents and resistance mechanisms on the definitions of resistance profiles, and (d) the globally expanding XDR/DTR high-risk lineages and their association with transferable resistance mechanisms. IMPLICATION: The evidence presented herein can be used for coordinated epidemiological surveillance and decision making at the European and global level.