Search

Streptococcus pneumoniae upper respiratory infections and pneumonia are often treated with macrolides, but recently macrolide resistance is becoming an increasingly important problem. The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the National Immunization Program of Peru in 2015. This study aimed to evaluate the temporal evolution of macrolide resistance in S. pneumoniae isolates collected in five cross-sectional studies conducted before and after this vaccine introduction, from 2006 to 2019 in Lima, Peru. A total of 521 and 242 S. pneumoniae isolates recovered from nasopharyngeal swabs from healthy carrier children < 2 years old (2 carriage studies) and samples from normally sterile body areas from pediatric patients with invasive pneumococcal disease (IPD) (3 IPD studies), respectively, were included in this study. Phenotypic macrolide resistance was detected using the Kirby-Bauer method and/or MIC test. We found a significant increase in macrolide resistance over time, from 33.5% to 50.0% in carriage studies, and from 24.8% to 37.5% and 70.8% in IPD studies. Macrolide resistance genes [ erm (B) and mef (A/E)] were screened using PCR. In carriage studies, we detected a significant decrease in the frequency of mef (A/E) genes among macrolide-resistant S. pneumoniae strains (from 66.7% to 50.0%) after introduction of PCV13. The most common mechanism of macrolide-resistant among IPD strains was the presence of erm (B) (96.0%, 95.2% and 85.1% in the 3 IPD studies respectively). Macrolide resistance was more common in serotype 19A strains (80% and 90% among carriage and IPD strains, respectively) vs. non-serotype 19A (35.5% and 34.4% among carriage and IPD strains, respectively). In conclusion, S. pneumoniae macrolide resistance rates are very high among Peruvian children. Future studies are needed in order to evaluate macrolide resistance trends among pneumococcal strains, especially now after the COVID-19 pandemic, since azithromycin was vastly used as empiric treatment of COVID-19 in Peru. [ABSTRACT FROM AUTHOR]

Background: Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children,24 months in Lima, Peru. Methods: ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR. Results: ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), p,0.05. Only 10% of isolates were resistant to nalidixic acid and none to ciprofloxacin or cefotaxime. Ampicillin and sulfamethoxazole resistance were most often associated with blaTEM (69%) and sul2 genes (68%), respectively. Tetracycline resistance was associated with tet(A) (49%) and tet(B) (39%) genes. Azithromycin inhibitory diameters were ≤15 mm in 36% of isolates, with 5% of those presenting the mph(A) gene. Conclusions: ETEC from Peruvian children are often resistant to older, inexpensive antibiotics, while remaining susceptible to ciprofloxacin, cephalosporins and furazolidone. Fluoroquinolones and azithromycin remain the drugs of choice for ETEC infections in Peru. However, further development of resistance should be closely monitored. [ABSTRACT FROM AUTHOR]

The study was aimed to describe the serotype, mechanisms of antimicrobial resistance, and virulence determinants in Shigella spp. isolated from Peruvian children. Eighty three Shigella spp. were serogrouped and serotyped being established the antibiotic susceptibility. The presence of 12 virulence factors (VF) and integrase 1 and 2, along with commonly found antibiotic resistance genes was established by PCR. S. flexneri was the most relevant serogroup (55 isolates, 66%), with serotype 2a most frequently detected (27 of 55, 49%), followed by S. boydii and S. sonnei at 12 isolates each (14%) and S. dysenteriae (four isolates, 5%). Fifty isolates (60%) were multi-drug resistant (MDR) including 100% of S. sonnei and 64% of S. flexneri . Resistance levels were high to trimethoprim-sulfamethoxazole (86%), tetracycline (74%), ampicillin (67%), and chloramphenicol (65%). Six isolates showed decreased azithromycin susceptibility. No isolate was resistant to nalidixic acid, ciprofloxacin, nitrofurantoin, or ceftriaxone. The most frequent resistance genes were sul 2 (95%), tet (B) (92%), cat (80%), dfrA1 (47%), bla OXA-1 like (40%), with intl 1 and intl 2 detected in 51 and 52% of the isolates, respectively. Thirty-one different VF profiles were observed, being the ipa H (100%), sen (77%), virA and icsA (75%) genes the most frequently found. Differences in the prevalence of VF were observed between species with S. flexneri isolates, particularly serotype 2a, possessing high numbers of VF. In conclusion, this study highlights the high heterogeneity of Shigella VF and resistance genes, and prevalence of MDR organisms within this geographic region. [ABSTRACT FROM AUTHOR]

Objective There is little information about vaccine schedule compliance in very-low-birth-weight infants in developing countries. The aim of the study was to describe the compliance with the vaccine schedule among this population in Lima, Peru. Patients and methods We conducted a prospective cohort study in four hospitals in Lima in infants with a birth-weight of less than 1500 g, followed from birth up to 12 months of age every 2 weeks. The date and age at administration of each vaccine was recorded Results 222 infants were enrolled. The median birth-weight was 1250 g (range 550–1499 g) and the median gestational age was 30.0 weeks (range 23–37 weeks). The mean age for the first pentavalent (DPT, Hib, HepB) and oral polio vaccine administration was 4.3 ± 1.4 months in infants with a birth-weight of <1000 g vs. 3.1 ± 1.0 in infants with a birth-weight 1000–1500 g ( p < 0.001); 4.1 ± 0.9 vs. 3.3 ± 1.1 for rotavirus ( p < 0.05); and 5.1 ± 2.1 vs. 4.3 ± 1.8 for the 7-valent pneumococcal conjugated vaccine. Only 35% had received the three doses of oral polio and pentavalent vaccine by seven months, although by nine months 81% had received these vaccines. Conclusions Vaccination of very-low-birth-weight infants in Peru is significantly delayed, especially in infants with a birth-weight of <1000 g and lower gestational age. Urgent educational interventions targeting physicians and nurses should be implemented in order to improve vaccination rates and timing in these high risk populations. [ABSTRACT FROM AUTHOR]

Objectives. To describe physicians' preferences of antibiotic use in children less than 5 years in health centers of primary level in three periurban districts in Lima, Perú. Material and methods. A structured survey was applied to 218 general practitioners from three health networks of Lima. The survey included six typical clinical cases in children under 5 years with questions about antibiotic use: the cases were common cold, pharyngitis, pneumonia, bronchial obstructive syndrome, watery diarrhea and dysentery. Results. 81.6% of the physicians responded that more than a quarter of the patients they attended were children under five years. 15.6% of the general physicians would use an antibiotic for common cold treatment. For dysentery treatment 90.4% would use antibiotics, the frequently used were Trimethoprim-Sulfamethoxazole (TMP-SMX) and Furazolidone. 86.2% of physicians would recommend an antibiotic for pharyngitis. In a watery diarrhea case 32.7% of the doctors would use. In the case of bronchospasm, 73% of the doctors would recommend an antibiotic. 96.3% would recommend antibiotics for pneumonia. The perception of the degree of mother's satisfaction increased the risk of inappropriate prescription of antibiotics OR: 1.6, p=0.031, 95% CI: 1.1-2.6). Conclusions. There is tendency to overuse antibiotics for diagnoses such as pharyngitis and bronchospasm, as well as in cases of watery diarrhea and common cold, the reason could be that a large number of children under five years are treated by general practitioners without training in pediatric care. [ABSTRACT FROM AUTHOR]

Objectives. To determine the frequency and clinical features of central nervous system infections caused by enterovirus in children treated at the Hospital Nacional Cayetano Heredia in Lima, Peru. Materials and methods. A prospective, descriptive study was performed from April 2008 to March 2010. Patients aged 1 month -- 14 years with clinical diagnosis of encephalitis or aseptic meningitis were included. We investigated the presence of enterovirus, herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2) and varicella-zoster virus (VZV) by polymerase chain reaction (PCR). Results. 97 patients were included, out of which 69 % had acute encephalitis and 31 % acute meningitis. Enteroviruses were identified in 52,6% of all acute non-bacterial central nervous system infections; corresponding to 83,3 % of meningitis and 38,8 % of encephalitis. There were no cases of infection due to HSV-1, HSV-2 or VZV. Enterovirus infections reached 82,9 % in the warm months (November-January) and 28,6 % in the colder months (May-July). Conclusions. Enteroviruses are the principal etiologic agents in acute aseptic meningitis and encephalitis in pediatric patients in Lima, Peru. Enteroviruses have a seasonal epidemiological pattern with a clear increase in the number of cases during the summer months. It is useful to have this rapid diagnostic method available as an aid in the management of acute central nervous system infections. [ABSTRACT FROM AUTHOR]

Introduction. Diarrheagenic E. coli (DEC) are a major cause of diarrhea in children in developing countries. However, they are not part of routine diagnosis in clinical laboratories. Objectives. To determine the DEC prevalence in Peruvian children and to describe the genetic variability of these strains. Materials and methods. A total of 8 003 E. coli strains previously isolated from eight different studies of diarrhea in children, mainly from peri-urban areas of Lima, were analyzed. Diagnosis of DEC was done with Multiplex real-time PCR using genes for each of the 6 DEC groups. Conventional PCR was performed for the detection of additional virulence genes. Results. Globally, the mean prevalence in diarrhea samples (n=4,243) was: enteroaggregative E. coli (EAEC) 9.9%, enteropathogenic E. coli (EPEC) 8.5%, enterotoxigenic E. coli (ETEC) 6.9%, diffusely adherent E. coli (DAEC) 4.8%, Shiga toxin-producing E. coli (STEC) 0.8% and enteroinvasive E. coli (EIEC) 0.6%. The relative frequency of each pathogen varies according to the age and the type of study. The main pathotypes in control samples (n=3,760) were EPEC (10.9%) and EAEC (10.4%). An important variability in the virulence genes frequency and molecular resistance mechanisms for each pathotype was found, without differences between diarrhea and control groups. Conclusions. DEC are a major cause of diarrhea in Peruvian children. These pathogens are highly heterogeneous. Additional studies are required to determine the prevalence in rural areas of Peru and in severe diarrhea cases. [ABSTRACT FROM AUTHOR]

Summary: Norovirus was detected in 17.4% of 224 diarrhoeal samples from children younger than 24 months of age in Lima, in whom all common pathogens had been excluded (pathogen negative). Norovirus was identified more frequently in children older than 12 months of age than in younger children (34% vs 8%, P <0.001). Among norovirus-positive samples, genogroup II was the predominant group (92%). Compared with rotavirus, norovirus episodes tended to be of shorter duration and less severe. The role of norovirus as a cause of diarrhoea and the ascertainment of its severity in developing countries needs further confirmation by future epidemiological studies. [ABSTRACT FROM AUTHOR]

• The frequency of pneumococcal nasopharyngeal carriage has decreased after PCV13 introduction. • The frequency of PCV13 serotypes has decreased after PCV13 introduction compared to the pre-PCV7 period. • Antimicrobial resistance in Streptococcus pneumoniae has increased after PCV13 compared to the pre-PCV7 period. To determinate the frequency of Streptococcus pneumoniae nasopharyngeal carriers, serotypes and antimicrobial resistance in healthy children in Lima, Peru, post-PCV13 introduction and to compare the results with a similar study conducted between 2006 and 2008 before PCV7 introduction (pre-PCV7). A cross-sectional multicenter study was conducted between January 2018 and August 2019 in 1000 healthy children under two years of age. We use standard microbiological methods to determinate S. pneumoniae from nasopharyngeal swab, Kirby Bauer and minimum inhibitory concentration methods to determinate antimicrobial susceptibility and whole genomic sequencing to determinate pneumococcal serotypes. The pneumococcal carriage rate was 20.8 % vs. 31.1 % in pre-PCV7 (p < 0.001). The most frequent serotypes were 15C, 19A and 6C (12.4 %, 10.9 % and 10.9 % respectively). The carriage of PCV13 serotypes after PCV13 introduction decreased from 59.1 % (before PCV7 introduction) to 18.7 % (p < 0.001). Penicillin resistance was 75.5 %, TMP/SMX 75.5 % and azithromycin 50.0 %, using disk diffusion. Penicillin resistance rates using MIC breakpoint for meningitis (MIC ≥ 0.12) increased from 60.4 % to 74.5 % (p = 0.001). The introduction of PCV13 in the immunization program in Peru has decreased the pneumococcal nasopharyngeal carriage and the frequency of PCV13 serotypes; however, there has been an increase in non-PCV13 serotypes and antimicrobial resistance. [ABSTRACT FROM AUTHOR]

The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. Coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinolone-resistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area. [ABSTRACT FROM AUTHOR]

Introduction. Diffusely adherent E. coli (DAEC) is the sixth recognized group of diarrheagenic E. coli. However, its association with diarrhea remains controversial. Variability in the adherence patterns of clinical strains is unknown. Objectives. To compare the adherence patterns between strains isolated from children with and without diarrhea. Materials and methods. A total of 31 DAEC strains were analyzed, 25 from children with diarrhea and 6 from asymptomatic (control) children, isolated from a cohort study of children under one year of age in the southern districts of Lima. DAEC were identified by PCR (daaD gene). The pattern and adherence score in HEp-2 cell culture were evaluated, Actin polimerization was determined by fluorescence actin staining (fAS) and motility was evaluated by conventional microbiology methods. Results. Diffuse adherence pattern was found in 88% of diarrhea samples and in the total of control strains. The number of bacteria adhered per cell was significantly lower in diarrhea samples (p<0.05). However, actin polymerization was greater in diarrhea samples (60% vs. 17%). Motility test was positive in 60% of the diarrhea samples and in all control samples. Conclusions. Our findings suggest a difference between adherence patterns, actin polymerization and motility between DAEC strains corresponding to diarrhea and control groups. The significance of these results must be confirmed with a bigger number of strains and determining the presence of virulence genes in the strains. [ABSTRACT FROM AUTHOR]

The objective of the present study was to characterize Salmonella enterica serovar Infantis isolated from chicken meat determining their clonal relationships with S. Infantis isolated from children with diarrhea. Fifteen meat-recovered S. Infantis were analyzed. Susceptibility levels to 14 antibacterial agents, the presence of ESBL and that of inducible plasmid-mediated AmpC (i-pAmpC) were determined by phenotypical methods. The presence of ESBL and pAmpC was confirmed by PCR, and detected ESBL-encoding genes were sequenced and their transferability tested by conjugation. The presence of gyrA mutations as well as Class 1 integrons was determined by PCR. Clonal relationships were established by REP-PCR and RAPD. In addition, 25 clinical isolates of S. Infantis were included in clonality studies. All meat-recovered S. Infantis were MDR, showing resistance to ampicillin, nitrofurans and quinolones, while none was resistant to azithromycin, ceftazidime or imipenem. ESBL (bla CTX-M-65) and i-pAmpC (bla DHA) were detected in 2 and 5 isolates respectively (in one case concomitantly), with bla CTX-M-65 being transferable through conjugation. In addition, 1 isolate presented a bla SHV gene. All isolates presented D 87 Y at GyrA, nalidixic acid active efflux pump and a Class 1 integron of ~1000 bp (aadA1). Clonal analysis showed that all isolates were related. Further they were identical to MDR bla CTX-M-65 -producing S. Infantis isolates causing children diarrhea in Lima. The dissemination of MDR bla CTX-M-65 -producing S. Infantis between marketed meat and children highlights a public health problem which needs be controlled at livestock level. • Multidrug resistant S. Infantis were recovered from food samples. • Presence of CTX-M-65 was detected in 2 food-recovered S. Infantis. • Clonal relations between food and human S. Infantis isolates are shown. [ABSTRACT FROM AUTHOR]