Estimation, Evaluation and Characterization of Carbapenem Resistance Burden from a Tertiary Care Hospital, Pakistan.

Carbapenem resistance has become major concern in healthcare settings globally; therefore, its monitoring is crucial for intervention efforts to halt resistance spread. During May 2019-April 2022, 2170 clinical strains were characterized for antimicrobial susceptibility, resistance genes, replicon and sequence types. Overall, 42.1% isolates were carbapenem-resistant, and significantly associated with Klebsiella pneumoniae (K. pneumoniae) (p = 0.008) and Proteus species (p = 0.043). Carbapenemases were detected in 82.2% of isolates, with blaNDM-1 (41.1%) associated with the ICU (p < 0.001), cardiology (p = 0.042), pediatric medicine (p = 0.013) and wound samples (p = 0.041); blaOXA-48 (32.6%) was associated with the ICU (p < 0.001), cardiology (p = 0.008), pediatric medicine (p < 0.001), general surgery (p = 0.001), general medicine (p = 0.005) and nephrology (p = 0.020); blaKPC-2 (5.5%) was associated with general surgery (p = 0.029); blaNDM-1/blaOXA-48 (11.4%) was associated with general surgery (p < 0.001), and wound (p = 0.002), urine (p = 0.003) and blood (p = 0.012) samples; blaOXA-48/blaVIM (3.1%) was associated with nephrology (p < 0.001) and urine samples (p < 0.001). Other detected carbapenemases were blaVIM (3.0%), blaIMP (2.7%), blaOXA-48/blaIMP (0.1%) and blaVIM/blaIMP (0.3%). Sequence type (ST)147 (39.7%) represented the most common sequence type identified among K. pneumoniae, along with ST11 (23.0%), ST14 (15.4%), ST258 (10.9%) and ST340 (9.6%) while ST405 comprised 34.5% of Escherichia coli (E. coli) isolates followed by ST131 (21.2%), ST101 (19.7%), ST10 (16.0%) and ST69 (7.4%). Plasmid replicon types IncFII, IncA/C, IncN, IncL/M, IncFIIA and IncFIIK were observed. This is first report describing the carbapenem-resistance burden and emergence of blaKPC-2-ST147, blaNDM-1-ST340 and blaNDM-1-ST14 in K. pneumoniae isolates and blaNDM-1-ST69 and blaNDM-1/blaOXA-48-ST69 in E. coli isolates coharboring extended-spectrum beta-lactamases (ESBLs) from Pakistan.

Emergence of multidrug-resistant ST11 blaKPC-2 producing Klebsiella pneumoniae coharboring blaCTX-M and blaSHV in Pakistan.

INTRODUCTION: Carbapenemases are primarily responsible for the intensified spread of multidrug-resistant (MDR) K. pneumoniae by virtue of antibiotics overuse. Therefore, frequent investigation of high-risk clones especially from developing world is crucial to curtail global spread. METHODOLOGY: In this observational study, 107 K. pneumoniae were retrieved and confirmed genotypically from April 2018 to March 2020 from tertiary care hospitals in Lahore, Pakistan. Carbapenemases and extended-spectrum ß-lactamases were verified by Polymerase Chain Reaction and Sanger sequencing. Multilocus sequence typing and plasmid replicon typing were used to assign clonal lineages and plasmid replicons. RESULTS: Among the K. pneumoniae, 72.9% (78/107) strains were carbapenem resistant (CR) with 65.4% (51/78) exhibiting carbapenemase producing phenotype. Among CR K. pneumoniae 38.5% (30/78) strains exhibited the following carbapenemase genotypes: blaNDM-1 (26.7%, 8/30), blaOXA-48 (26.7%, 8/30), blaKPC-2 (20.0%, 6/30), blaVIM (10.0%, 3/30), blaNDM-1/blaOXA-48 (10.0%, 3/30), blaOXA-48/blaVIM (3.3%, 1/30) and blaOXA-48/blaIMP (3.3%, 1/30). Tigecycline and polymyxin-B retained susceptible profile. ß-lactam drugs showed intermediate to high resistance. The occurrence of CR K. pneumoniae infections was significantly associated with wound (39.7%, p = 0.0007), pus (38.5%, p = 0.009), general surgery (34.6%, p = 0.002) and intensive-care unit (26.9%, p = 0.04). blaKPC-2 producing K. pneumoniae coharboring blaCTX-M/blaSHV (66.7%) and blaCTX-M (33.3%) exhibited sequence type (ST) 258 (n = 4) and ST11 (n = 2) sequence types with IncFII, IncN, IncFIIA, IncL/M and IncFIIK plasmids. CONCLUSIONS: This is the first report describing the emergence of MDR blaKPC-2 producing K. pneumoniae ST11 coharboring blaCTX-M and blaSHV in Pakistan.

Characterization of Genomic Diversity among Carbapenem-Resistant Escherichia coli Clinical Isolates and Antibacterial Efficacy of Silver Nanoparticles from Pakistan.

The emergence of carbapenem-resistant Escherichia coli (E. coli) is considered an important threat to public health resulting in resistance accumulation due to antibiotics misuse and selection pressure. This warrants periodic efforts to investigate and develop strategies for infection control. A total of 184 carbapenem-resistant clinical strains of E. coli were characterized for resistance pattern, resistance genes, plasmids, sequence types and in vitro efficacy of silver nanoparticles (AgNPs). Carbapenem resistance was prevalent in E. coli isolated from female patients (64.7%), urine samples (40.8%) and surgical wards (32.1%). Polymyxin-B showed higher susceptibility. ESBLs and carbapenemases were produced in 179 and 119 isolates, respectively. Carbapenemase-encoding genes were observed among 104 strains with blaNDM-1 (45.1%), blaOXA-48 (27%), blaNDM-7 (3.8%), blaNDM-1/blaOXA-48 (15.4%), blaNDM-7/blaOXA-48 (2.9%), blaOXA-48/blaVIM (3.8%) and blaNDM-1/blaVIM (2%). ESBL resistance genes were detected in 147 isolates, namely blaSHV (24.9%), blaCTX-M (17.7%), blaTEM (4.8%), blaSHV/blaCTX-M (29.2%), blaSHV/blaTEM (15%) and blaCTX-M/blaTEM (8.8%). ST405 (44.4%) and ST131 (29.2%) were more frequent sequence types with ST101 (9.7%), ST10 (9.7%) and ST648 (7%). The replicon types IncFII, IncFIIK, IncA/C, IncN and IncL/M were detected. The combination of MEM/AgNPs remained effective against carbapenemase-positive E. coli. We reported genetically diverse E. coli strains coharboring carbapenemases/ESBLs from Pakistan. Moreover, this study highlights the enhanced antibacterial activity of MEM/AgNPs and may be used to manage bacterial infections.

Impact of antibiotic withdrawal and starvation conditions on plasmid elimination and consequent loss of resistance.

OBJECTIVE: To assess resistance-loss due to plasmid elimination under experimental conditions, including withdrawal of antibiotics and administration of starvation conditions. METHODS: The experimental study was conducted at the Department of Pathology, King Edward Medical University, Lahore, Pakistan, from July to December 2019. A single sensitive clinical isolate of escherichia coli, showing resistance towards ampicillin was collected and separately sub-cultured in three different culture broths: tryptic soya broth, minimal broth and control broth for a period of one month under standard laboratory conditions. Minimum inhibitory concentrations of the strains were calculated after every seven days to check antibiotic susceptibility. RESULTS: Minimum inhibitory concentrations of the initial escherichia coli strain measured on Day 1 was 6mg/mL and it became sensitive after continual sub-culturing in the absence of antibiotics in 21 days. Due to starvation conditions, the bacterial strain exhibited sensitivity to an even lower antibiotic concentration of 1.5mg/mL on the 28th day. Bacterial growth inhibition zones determined by disc diffusion method using an ampicillin disc of 10µg/mL showed no zone of inhibition. CONCLUSIONS: Provision of starvation conditions and withdrawal of antibiotic allowed the escherichia coli strain to exhibit gradual loss of resistance over a period of time.

A rare case of extensively drug-resistant Salmonella typhi meningitis in a 9-year old: a case report.

Meningitis caused by Salmonella typhi is rare and is generally seen in infants. We report a case of a 9-year-old boy with extensively drug-resistant S. typhi meningitis. The patient was diagnosed using a culture sensitivity test and successfully treated with meropenem. Culture sensitivity may be included in routine testing for the diagnosis of S. typhi especially in developing countries due to high burden of disease and emergence of drug resistance.

Three years mortality analysis in general surgery patients.

OBJECTIVE: Surgical patient mortality is progressively being measured for providing better management and care in different healthcare systems world-wide. The aim of this study was to assess mortality within a surgical department and to evaluate components associated with surgical and non- surgical deaths. METHODS: We retrospectively collected data including all admissions, both operative and non-operative, surgical procedures and reason of admission (for non-operative) and mortalities within three-year period (2015-2017) from Surgical Unit-2, JPMC Karachi. We assessed type of operations, admission, patient related factors including age, sex, co-morbid factors, reason, time and onset of presentation, operative notes, events, clinical cause and date/ time of death. RESULTS: The total admissions of 5730 patients were observed in surgical ward-2 during the period of 1st of January 2015 and 31st of December 2017. There were a total of 291 deaths during this period (5.07% overall mortality rate). GIT related (peritonitis/ obstruction) (58.41%), biliarytract/ pancreatic causes (10.9%), road traffic accidents/ blunt trauma (7.21%), firearm injuries (1.71%) followed by GIT malignancies (4.81%) and Non-GIT malignancies (2.06%) were observed to be the main/ leading causes of death. Of the 291 deaths, males were 179 (6.70%) and females were 112 (3.66%). Male to female ratio of morality came out to be 1.6:1. The cause of death in our patients was sepsis (58.41%), cardiopulmonary arrest (13.0%), trauma/ gunshot injuries 8.93%, advanced malignancies (6.87%), pulmonary embolism (6.18%), myocardial infarction (5.49%) and post op bleeding (1.03%). Mortality due to delayed presentation of patient i.e. after five days of onset of symptoms (62.88%), Surgical decision/ exploration after 24 hours (33.67%). The lack of availability of ICU/ HDU in hospital contributed (51.01%) to the total surgical mortality. CONCLUSIONS: As per the study of three years (2015-2017) a fluctuating mortality pattern is observed. The increment of death was mainly among the unavoidable deaths such as GIT and Non GIT related sepsis, advanced malignancies, trauma and firearm injuries, pulmonary embolism myocardial infarction, a moderate role has also been played by miscellaneous group of patients. Delayed presentation of the patients after appearance of first symptom/ symptoms, delayed surgical decision/ exploration also came out to be significantly important factors in our studies elaborating the major difference in mortality rate.