Molecular Characterization of Extended-Spectrum β-Lactamase-Producer Klebsiella pneumoniae Isolates Causing Neonatal Sepsis in Peru

High prevalence of multidrug-resistant Enterobacterales carrying extended-spectrum beta-lactamase and AmpC genes isolated from neonatal sepsis in Ahvaz, Iran

OBJECTIVES

In the recent years, multidrug resistant (MDR) neonatal septicemia-causing Enterobacterales has been dramatically increased due to the extended-spectrum beta-lactamases (ESBLs) and AmpC enzymes. This study aimed to assess the antibiotic resistance pattern, prevalence of ESBLs/AmpC beta-lactamase genes, and Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) fingerprints in Enterobacterales isolated from neonatal sepsis.

RESULTS

In total, 59 Enterobacterales isolates including 41 (69.5%) Enterobacter species, 15 (25.4%) Klebsiella pneumoniae and 3 (5.1%) Escherichia coli were isolated respectively. Resistance to ceftazidime and cefotaxime was seen in all of isolates. Furthermore, all of them were multidrug-resistant (resistant to three different antibiotic categories). The phenotypic tests showed that 100% of isolates were ESBL-positive. Moreover, AmpC production was observed in 84.7% (n = 50/59) of isolates. Among 59 ESBL-positive isolates, the highest percentage belonged to blaCTX-M-15 gene (66.1%) followed by blaCTX-M (45.8%), blaCTX-M-14 (30.5%), blaSHV (28.8%), and blaTEM (13.6%). The frequency of blaDHA, blaEBC, blaMOX and blaCIT genes were 24%, 24%, 4%, and 2% respectively. ERIC-PCR analysis revealed that Enterobacterales isolates were genetically diverse. The remarkable prevalence of MDR Enterobacterales isolates carrying ESBL and AmpC beta-lactamase genes emphasizes that efficient surveillance measures are essential to avoid the more expansion of drug resistance amongst isolates.

Traditional marketed meats as a reservoir of multidrug-resistant Escherichia coli

This study aimed to analyze Escherichia coli from marketed meat samples in Peru. Sixty-six E. coli isolates were recovered from 21 meat samples (14 chicken, 7 beef), and antimicrobial resistance levels and the presence of mechanisms of antibiotic resistance, as well as clonal relationships and phylogeny of colistin-resistant isolates, were established. High levels of antimicrobial resistance were detected, with 93.9% of isolates being multi-drug resistant (MDR) and 76.2% of samples possessing colistin-resistant E. coli; of these, 6 samples from 6 chicken samples presenting mcr-1-producer E. coli. Colistin-resistant isolates were classified into 22 clonal groups, while phylogroup A (15 isolates) was the most common. Extended-spectrum β-lactamase- and pAmpC-producing E. coli were found in 18 and 8 samples respectively, with blaCTX-M-55 (28 isolates; 16 samples) and blaCIT (8 isolates; 7 samples) being the most common of each type. Additionally, blaCTX-M-15, blaCTX-M-65, blaSHV-27, blaOXA-5/10-like, blaDHA, blaEBC and narrow-spectrum blaTEM were detected. In addition, 5 blaCTX-M remained unidentified, and no sought ESBL-encoding gene was detected in other 6 ESBL-producer isolates. The tetA, tetE and tetX genes were found in tigecycline-resistant isolates. This study highlights the presence of MDR E. coli in Peruvian food-chain. The high relevance of CTX-M-55, the dissemination through the food-chain of pAmpC, as well as the high frequency of unrelated colistin-resistant isolates is reported.

Worrying levels of antimicrobial resistance in Gram-negative bacteria isolated from cell phones and uniforms of Peruvian intensive care unit workers

BACKGROUND

Healthcare worker (HCW) uniforms and cell phones are involved in pathogen transmission. This study aimed to characterize pathogenic microorganism isolates from HCW uniforms and cell phones.

METHODS

Gram-negative microorganisms were recovered from HCW uniforms and cell phones. Antimicrobial susceptibility and the presence of extended-spectrum β-lactamases (ESBL) and carbapenemases were determined.

RESULTS

Escherichia coli was the most prevalent microorganism. Overall, high levels of resistance to cephalosporins, quinolones, co-trimoxazole and colistin were found. ESBL were mainly related to blaCTX-M-15 and blaSHV- genes. Carbapenem-resistant isolates presented as blaKPC or blaNDM.

CONCLUSIONS

High levels of antimicrobial resistance, including colistin, were detected. Therefore, strategies are urgently needed to prevent bacterial dissemination.

High Prevalence of blaCTX-M in Fecal Commensal Escherichia coli from Healthy Children

Background

Antibiotic-resistant Escherichia coli can colonize the intestinal tract of healthy children, causing concern when antibiotic resistance is related to the presence of transferable mechanisms, such as extended-spectrum β-lactamases (ESBLs).

Materials and Methods

Fecal samples from 41 healthy children from two villages of rural Peru were cultured on ceftriaxone-disks. ESBL production was confirmed with double disk synergy. In all ESBL-produced isolates, antibiotic susceptibility to 12 antibacterial agents was established by disk diffusion, while clonal relationships were determined by repetitive extragenic palindromic-polymerase chain reaction (REP-PCR). Presence of ST131 was determined using PCR.

Results

Ceftriaxone-resistant microorganisms were recovered from 39 samples belonging to 22 out of 41 children (53.7%). Of these, 80 ceftriaxone-resistant and two ceftriaxone-intermediate E. coli from inside ceftriaxone-halos were confirmed as ESBL-producers. All isolates were multidrug-resistant. In 79/80 (98.8%) ceftriaxone-resistant isolates, the presence of bla_CTX-M was detected alone (58 isolates, or together with other β-lactamase (bla_TEM, 17 isolates; bla_OXA-1-like, 3 isolates; bla_TEM + bla_OXA-1-like, 1 isolate), while in one isolate no such ESBL was identified. The two ceftriaxone-intermediate isolates recovered from the same sample, carried a bla_TEM and bla_SHV respectively. Thirty-four different clones were identified, with 4 clones being recovered from different samples from the same child. Twelve clones were disseminated among different children, including 5 clones disseminated between both villages. Two clones, accounting for 3 isolates and both recovered from the same children, belonged to E. coli ST131.

Conclusion

This study demonstrates high prevalence of ESBL-carriers among healthy children living in a rural area of Peru, stressing the need for continuous surveillance and search for public health control measures.

Evolution of Antimicrobial Resistance Levels of ESKAPE Microorganisms in a Peruvian IV-Level Hospital

BACKGOUND

The members of the so-called ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) are a frequent cause of severe infection, ranking among the most relevant causes of hospital infections. In Peru, few studies, often focused in a single ESKAPE microorganism, have been performed, but none providing an overall and comprehensive long-time analysis of the antibiotic resistance of ESKAPE microorganisms. In the present study, the evolution of antimicrobial resistance levels of ESKAPE microorganisms isolated during 2009 - 2010 (Period 1) and 2012 - 2014 (Period 2) in a IV-level hospital in Lima was analyzed.

MATERIALS AND METHODS

ESKAPE microorganisms were isolated from inpatients clinical samples. Bacterial identification, as well as antimicrobial susceptibility levels for up to 29 antimicrobial agents and presence of Extended-Spectrum β-Lactamases (only established in K. pneumoniae) were determined using automatic methods.

RESULTS

Of 9,918 clinical isolates, 1,917/3,777 (50.8%) [JAN/2009-JUN/2010 (Period 1)] and 4764/6141 (46.4%) [JAN/2012-DEC/2014 (Period 2)] belonged to the ESKAPE group (P <0.0001). ESKAPE were more frequent in the intensive care unit (ICU) (P <0.0001). E. faecium decreased from 5.1% to 4.1% (P <0.5), S. aureus from 10.5% to 7.0% (P <0.05), and P. aeruginosa from 12.9% to 11.6% (P <0.05), while, A. baumannii increased from 5.0% to 6.7% (P <0.05), mainly related to an increase in ICU isolates (8.4% vs. 17.1%; P <0.05). Overall, high levels of antimicrobial resistance were detected, but with few exceptions (e.g. vancomycin in E. faecium), antibiotic resistance levels remained stable or lower in Period 2. Contrarily, A. baumannii showed significantly increased resistance to different cephalosporins, carbapenems and amoxicillin plus sulbactam.

CONCLUSION

The introduction of a successful extensively drug-resistant A. baumannii clone in the ICU is suspected. The isolation of ESKAPE and levels of antibiotic resistance levels have reduced over time.

Emerging Threat of Multidrug Resistant Pathogens From Neonatal Sepsis

Multidrug-resistant (MDR) pathogens are responsible for a substantial burden of morbidity and mortality from neonatal sepsis; however, data on these sepsis-related pathogens among hospitalized neonates in China are not well characterized. In this study, a total of 240 strains were isolated from four Women and Children's hospitals in Southwest China between 2014 and 2019. Of these included pathogens, 104 (43.33%) were gram-positive bacteria, 129 (53.75%) were gram-negative bacteria, and 7 (2.92%) were fungi. Escherichia coli (E. coli, 34.01%) and Klebsiella pneumoniae (K. pneumoniae, 15.35%) were the main pathogen of neonate bacteremia. ST167 were the most prevalent STs in E. coli and ST11 in K. pneumoniae. Our study found that E. coli (62.71%) was the predominate pathogen of early-onset sepsis, among which 64.86% were MDR. Late-onset sepsis was mainly caused by K. pneumoniae (28.31%) and E. coli (24.78%), with showing that 78.33% of these pathogens were MDR. Notably, the prevalence of EO/LO pathogens were quite different from Indian and south of China. Moreover, we found that bla _CTX-M (42.06%) was most dominant resistant genes with about a third isolates (31.09%) were positive for bla _CTX-M-15. All the carbapenem-resistant K. pneumoniae were positive for NDM-1. Moreover, late-onset sepsis and antibiotic exposure were significantly associated with MDR infection. Emerging multi-resistant pathogens of sepsis posts a serious threat to neonatal outcomes and emphasizes an urgent need to control their further spread.

Molecular characterization of invasive Enterobacteriaceae from pediatric patients in Central and Northwestern Nigeria

Background

Bacteremia is a leading cause of mortality in developing countries, however, etiologic evaluation is infrequent and empiric antibiotic use not evidence-based. Here, we evaluated the patterns of ESBL resistance in children enrolled into a surveillance study for community acquired bacteremic syndromes across health facilities in Central and Northwestern Nigeria.

Method

Blood culture was performed for children aged less than 5 years suspected of having sepsis from Sept 2008-Dec 2016. Blood was incubated using the BACTEC^00AE system and Enterobacteriacea identified to the species level using Analytical Profile Index (API20E^®). Antibiotic susceptibility profile was determined by the disc diffusion method. Real time PCR was used to characterize genes responsible for ESBL production.

Result

Of 21,000 children screened from Sept 2008-Dec 2016, 2,625(12.5%) were culture-positive. A total of 413 Enterobacteriaceae available for analysis were screened for ESBL. ESBL production was detected in 160 Enterobacteriaceae, high resistance rates were observed among ESBL-positive isolates for Ceftriaxone (92.3%), Aztreonam (96.8%), Cefpodoxime (96.3%), Cefotaxime (98.8%) and Trimethoprim/sulfamethoxazole (90%), while 87.5%, 90.7%, and 91.9% of the isolates were susceptible to Imipenem, Amikacin and Meropenem respectively. Frequently detected resistance genes were blaTEM—83.8% (134/160), and, blaCTX-M 83.1% (133/160) followed by blaSHVgenes 66.3% (106/160). Co-existence of blaCTX-M, blaTEM and blaSHV was seen in 94/160 (58.8%), blaCTX-M and blaTEM in 118/160 (73.8%), blaTEM and blaSHV in 97/160 (60.6%) and blaCTX-M and blaSHV in 100/160 (62.5%) of isolates tested.

Conclusion

Our results indicate a high prevalence of bacteremia from ESBL Enterobacteriaceae in this population of children. These are resistant to commonly used antibiotics and careful choice of antibiotic treatment options is critical. Further studies to evaluate transmission dynamics of resistance genes could help in the reduction of ESBL resistance in these settings.

Spread of ST348 Klebsiella pneumoniae Producing NDM-1 in a Peruvian Hospital

The aim of this study was to characterize carbapenem-resistant Klebsiella pneumoniae (CR-Kp) isolates recovered from adults and children with severe bacteremia in a Peruvian Hospital in June 2018. Antimicrobial susceptibility was determined by disc/gradient diffusion and broth microdilution when necessary. Antibiotic resistance mechanisms were evaluated by PCR and DNA sequencing. Clonal relatedness was assessed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Plasmid typing was performed with a PCR-based method. Thirty CR-Kp isolates were recovered in June 2018. All isolates were non-susceptible to all β-lactams, ciprofloxacin, gentamicin and trimethoprim-sulfamethoxazole, while mostly remaining susceptible to colistin, tigecycline, levofloxacin and amikacin. All isolates carried the bla_NDM-1 gene and were extended spectrum β-lactamase (ESBL) producers. PFGE showed four different pulsotypes although all isolates but two belonged to the ST348 sequence type, previously reported in Portugal. bla_NDM-1 was located in an IncFIB-M conjugative plasmid. To our knowledge, this is the first report of an New Delhi metallo-β-lactamase (NDM)-producing K. pneumoniae recovered from both children and adults in Lima, Peru, as well as the first time that the outbreak strain ST348 is reported in Peru and is associated with NDM. Studies providing epidemiological and molecular data on CR-Kp in Peru are essential to monitor their dissemination and prevent further spread.

Neonatal sepsis at Mulago national referral hospital in Uganda: Etiology, antimicrobial resistance, associated factors and case fatality risk

Background

Sepsis is the third most common cause of death among neonates, with about 225,000 newborns dying every year globally. Data concerning the microbial etiology of neonatal sepsis and antimicrobial resistance profiles of its causative agents are necessary to inform targeted and effective treatment and prevention strategies.

Objective

To determine the proportion of newborns with symptoms and signs of sepsis who had a positive blood culture, its bacterial etiology, the antimicrobial resistance patterns as well as the factors associated with culture-positivity and case fatality at Mulago national referral hospital in Uganda.

Methods

We conducted a cross-sectional study among 359 neonates with symptoms and signs of sepsis who presented to the pediatric emergency care unit of Mulago national referral hospital from mid-January to end of December 2018. We performed blood culture and antimicrobial susceptibility testing, and conducted polymerase chain reaction to identify methicillin-resistant Staphylococcus aureus (MRSA) isolates. We used multivariable logistic regression to estimate the association between potential risk factors and culture-positive neonatal sepsis.

Findings

Of the 359 neonates recruited, 46 (12.8%; 95% CI 9.5%, 16.7%) had a positive blood culture. The predominant isolated bacteria were Staphylococcus aureus in 29 (63.0%), Escherichia coli in seven (15.2%), and Klebsiella pneumoniae in five (10.9%). Of the 46 pathogens, 73.9% were resistant to ampicillin, 23.9% to gentamicin and 8.7% to ceftriaxone. We isolated MRSA from the blood specimens of 19 (5.3%) of the 359 neonates, while 3 (0.8%) grew extended spectrum beta lactamase producers. The case fatality risk among neonates with neonatal sepsis was 9.5% (95% CI: 6.6%, 13.0%). Cesarean section delivery was strongly associated with culture-positive sepsis (adjusted odds ratio 3.45, 95% CI: 1.2, 10.1).

Conclusion

One in eight neonates with clinical signs of sepsis grew a likely causative bacterial pathogen. S. aureus was the main pathogen isolated and a third of these isolates were MRSA. A significant proportion of the isolated bacterial pathogens were resistant to the first and second line antibiotics used for the treatment of neonatal sepsis. There is need to revisit the current treatment guidelines for neonatal sepsis.

Antibiotic-Resistant Escherichia coli in Drinking Water Samples from Rural Andean Households in Cajamarca, Peru

Antibiotic resistance in pathogenic bacteria is a serious public health issue. The growing threat is a cause for concern and action to prevent the emergence of new resistant strains and the spread of existing ones to humans via the environment. This study aimed at identifying fecal pathogens in drinking water obtained from rural Andean households from Cajamarca, Peru, and measuring the antibiotic resistance profile of Escherichia coli. The study was embedded within a community-randomized controlled trial among 102 communities in the northern highlands of the Cajamarca region, Peru. Of 314 samples, 55.4% (95% CI [49.7, 61.0], n = 174) were identified as thermotolerant coliforms. Among the samples positive for thermotolerant coliform, E. coli was isolated in 37.3% (n = 117), Klebsiella spp. in 8.0% (n = 25), Enterobacter spp. in 5.1% (n = 16), and Citrobacter spp. in 2.5% (n = 8). Of the 117 E. coli samples, 48.7% (95% CI [39.4, 58.1], n = 57) showed resistance to any antibiotic. The E. coli antibiotic resistance profile showed highest resistance against tetracycline (37.6%), ampicillin (34.2%), sulfamethoxazole-trimethoprim (21.4%), and nalidixic acid (13%). Some 19.7% (95% CI [12.9, 28.0], n = 23) of the E. coli isolates displayed multidrug resistance, defined as resistance to at least three classes of antibiotics. The CTX-M-3 gene, which encodes extended-spectrum resistance to beta-lactamase antibiotics, was found in one isolate. The high prevalence of fecal contamination in drinking water highlights the importance of household water treatment methods. Likewise, the high levels of antibiotic resistance found indicate a need for further research to identify the origins of potential environmental contamination, misuse, or inadequate disposal of antibiotics.

Antimicrobial-resistant Gram-negative infections in neonates: burden of disease and challenges in treatment

PURPOSE OF REVIEW

This review summarizes the main challenges of antimicrobial resistance (AMR) in the neonatal population with a special focus on multidrug-resistant (MDR) Gram-negative pathogens.

RECENT FINDINGS

MDR-Gram-negative bacteria are a great concern in the neonatal population, with a worldwide rise in the reported incidence and with very limited therapeutic options. Extended-spectrum β-lactamase and carbapenem-resistant Enterobacteriaceae (CRE) have been reported as responsible for neonatal ICU outbreaks. Hospital data from low/middle-income countries show high proportions of isolates from neonates resistant to the WHO first-line and second-line recommended treatments. The spread of CRE has resulted in old antibiotics, such as colistin and fosfomycin, to be considered as alternative treatment options, despite the paucity of available data on safety and appropriate dosage.

SUMMARY

Improved global neonatal AMR surveillance programmes including both epidemiology and clinical outcomes are critical for defining the burden and designing interventions. The optimal empiric treatment for neonatal sepsis in settings of high rates of AMR is currently unknown. Both strategic trials of older antibiotics and regulatory trials of new antibiotics are required to improve clinical outcomes in MDR-Gram-negative neonatal sepsis.

Multidrug-Resistant Microorganisms Colonizing Lower Extremity Wounds in Patients in a Tertiary Care Hospital, Lima, Peru

Multidrug-resistant organism (MDRO) infections cause high morbidity and mortality, and high costs to patients and hospitals. The study aims were to determine the frequency of MDRO colonization and associated factors in patients with lower-extremity wounds with colonization. A cross-sectional study was designed during November 2015 to July 2016 in a tertiary care hospital in Lima, Peru. A wound swab was obtained for culture and susceptibility testing. MDRO colonization was defined if the culture grew with methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and/or extended spectrum beta-lactamase (ESBL) microorganisms. The frequency of MDRO wound colonization was 26.8% among the 97 patients enrolled. The most frequent MDRO obtained was ESBL-producing Escherichia coli, which was significantly more frequent in chronic wounds versus acute wounds (17.2% versus 0%, P < 0.05). Infection control measures should be implemented when patients with chronic lower-extremity wounds are admitted.

Resistance to quinolones, cephalosporins and macrolides in Escherichia coli causing bacteraemia in Peruvian children

OBJECTIVES

To characterise the β-lactam, quinolone and macrolide resistance levels and mechanisms in 62 Escherichia coli isolates causing bacteraemia in Peruvian children.

METHODS

Minimum inhibitory concentrations (MICs) of ciprofloxacin, nalidixic acid (NAL) and azithromycin were determined in the presence and absence of Phe-Arg-β-naphthylamide. Susceptibility to other 14 antimicrobial agents was also established. Extended-spectrum β-lactamases (ESBLs) were identified, and mutations in gyrA and parC as well as the presence of transferable mechanisms of quinolone resistance (TMQR) and macrolide resistance (TMMR) were determined.

RESULTS

Fifty isolates (80.6%) were multidrug-resistant. High proportions of resistance to ampicillin (93.5%), NAL (66.1%) and trimethoprim/sulfamethoxazole (66.1%) were observed. No isolate showed resistance to carbapenems and only two isolates were resistant to nitrofurantoin. Twenty-seven isolates carried ESBL-encoding genes: 2 bla_SHV-12; 13 bla_CTX-M-15; 4 bla_CTX-M-2; 6 bla_CTX-M-65; and 2 non-identified ESBLs. Additionally, 27 bla_TEM-1 and 9 bla_OXA-1-like genes were detected. All quinolone-resistant isolates showed target mutations, whilst TMQR were present in four isolates. Efflux pumps played a role in constitutive NAL resistance. The association between quinolone resistance and ESBL production was significant (P=0.0011). The mph(A) gene was the most frequent TMMR (16 isolates); msr(A) and erm(B) genes were also detected. Only one TMMR-carrying isolate [presenting mph(A) and erm(B) concomitantly] remained resistant to azithromycin when efflux pumps were inhibited.

CONCLUSIONS

A variety of ESBL-encoding genes and widespread of bla_CTX-M-15 in Lima has been shown. The role of efflux pumps in azithromycin resistance needs to be further evaluated, as well as effective control of the use of antimicrobial agents.

Characterisation of the first KPC-2-producing Klebsiella pneumoniae ST340 from Peru

OBJECTIVES

The aim of this study was to characterise a KPC-carrying Klebsiella pneumoniae isolate from a Peruvian hospital setting.

METHODS

The identity of the isolate was confirmed by amplification and sequencing of the 16S rRNA gene, and the antibiotic resistance profile was determined by disk diffusion and automated methods The sequence type (ST) and phylogenetic group were established by PCR. The presence of different β-lactamase genes was determined, including bla_MBL, bla_KPC, bla_CTX-M, bla_SHV, bla_OXA-1-like, bla_OXA-2-like, bla_OXA-5-like, bla_OXA-48-like and bla_TEM and up to six different plasmid-encoded AmpC genes as well as class 1 integrons. The conjugability of β-lactam resistance was assessed by conjugation.

RESULTS

The isolate was confirmed to be K. pneumoniae classified as belonging to the KpI phylogenetic group within ST340, which belongs to the high-risk clonal complex 258 (CC258). The isolate was resistant to all β-lactam agents tested, with only the presence of a non-conjugative bla_KPC-2 gene being detected and carried in a non-classical genetic structure.

CONCLUSIONS

This is the first description of a member of CC258 and of a bla_KPC-2 gene in Peru. Intensive surveillance is needed to determine the relevance of both in this area.

Neonatal Sepsis in Haiti

Infections (including sepsis, meningitis, pneumonia and tetanus) stand as a major contributor to neonatal mortality in Haiti (22%). Infants acquire bacteria that cause neonatal sepsis directly from the mother's blood, skin or vaginal tract either before or during delivery. Nosocomial and environmental pathogens introduce further risk after delivery. The absence of cohesive medical systems and methods for collecting information limits the available data in countries such as Haiti. This study seeks to add more information on the burden of severe bacterial infections and their etiology in neonates of Haiti. Researchers conducted a secondary retrospective analysis of a de-identified database from the Neonatal Intensive Care Unit (NICU) at Nos Petit Frères et Soeurs-St. Damien Hospital (NPFS-SDH). Records from 1292 neonates admitted to the NICU at NPFS-SDH in Port-au-Prince Haiti from 2013 to 2015 were reviewed. Sepsis accounted for 708 of 1292 (54.8%) of all admissions to the NICU. Infants admitted for sepsis had a mortality rate of 23% (163 of 708 infants admitted for sepsis). The most common organism cultured was Streptococcus agalactiae, followed by Klebsiella pneumoniae, Pseudomonas aeroginusa, Enterobacter aerogenes, Staphylococcus aureus and Proteus mirabillis Failure to order or obtain a culture was associated with an increased fatality (odds ratio 2.4) for infants with sepsis. Resistance should be a concern when treating empirically.